This document discusses the requirements for UV-Visible spectrophotometers as specified in the USP and EP pharmacopoeias. It states that the USP and EP provide performance tests for wavelength accuracy, photometric accuracy, stray light, and resolution. Certified reference materials traceable to NIST or NPL standards are needed to properly perform these tests and ensure instruments meet regulatory compliance. The document then examines the specific test methods and requirements outlined in the USP and EP sections on UV-Visible spectrophotometry. It notes that Thermo Scientific offers a variety of certified reference materials and validation documentation to help laboratories achieve and maintain compliance with pharmacopoeia standards.
Recently, a new high-sensitivity detector was introduced that provides improved UHPLC system performance and includes new features that improve workplace efficiency.
This presentation introduces this technology and provides a description of its use for impurity analysis. For more information, go to www.ssi.shimadzu.com or follow Shimadzu on Twitter @shimadzussi.
Thanks for viewing!
This document outlines a test to determine if any reaction exists between latex gloves, cleanroom wipers, and acetone solvent through qualitative FTIR analysis. Gloves, wipers, and acetone were agitated together and their weights measured before and after. Extracts were placed in sample bottles and sent for FTIR testing to identify any leached residues. The goal was to evaluate potential non-volatile residues from cleaning materials that could remain after cleaning.
Calibration - UV VIS Spectrophotometer, HPLC, Gas Chromatograph, IR spectroph...SELINA SRAVANTHI
Calibration of analytical instruments is important to ensure accurate measurements. It involves comparing instruments to more precise reference standards. Calibrating UV-Vis spectrophotometers involves checking wavelength accuracy using holmium filters, absorbance accuracy using potassium dichromate, stray light levels, resolution, and linearity. Calibrating IR spectrometers involves checking wavenumber accuracy using polystyrene, resolution, transmittance levels, linearity, and reproducibility. Calibrating fluorimeters involves setting excitation/emission wavelengths and adjusting the concentration readout using standards. Calibrating HPLCs involves checking flow rate accuracy and gradient performance using solvent mixtures.
Calibration of infrared (IR) spectroscopy ensures the instrument provides accurate measurements. The calibration process involves using a polystyrene film standard to produce an IR spectrum. The spectrum is compared to a reference standard to check if the strongest peak is within 95% of the maximum. If not, adjustments are made to correct the signal. Periodic calibration is needed to account for instrument drift over time and ensure precise results.
Spectrolytic has become the pioneer in the supply of cost effective, mid-infrared spectroscopy solutions, offering the lowest cost per measurement point. Spectrolytic’s product portfolio moves the powerful analytical technology of mid-infrared spectroscopy (FTIR) out of the laboratory into the field, providing real time analysis anywhere, anytime.
Spectrolytic GmbH develops a static FTIR spectrometer that uses a patented optical design without moving parts. This makes it faster, more robust, and suitable for portable applications compared to conventional FTIR spectrometers which use a moving mirror. The static FTIR can process all wavelengths in parallel at speeds up to 50Hz. It finds applications in areas like medical analysis, process monitoring, and analysis of fast moving samples due to its measurement speed, robustness, and accuracy.
Spectrolytic was founded with the aim of making spectroscopy solutions available to the masses and to broaden the view of usability.
Spectrolytic GmbH is a developer and supplier of infrared spectrometers and related solutions for a wide range of applications and markets. It also provides development and manufacturing services to third parties for both systems and solutions.
Spectrolytic GmbH has its registered office in Wernberg-Köblitz, Germany, and its operating HQ in Wackersdorf, Germany. The Companies design, manufacture (internally and/or externally) a range of spectroscopy systems for a number of market sectors including but not limited to industrial and consumer applications.
The Company also provide technology consulting, system design and development services, plus related manufacturing to customers on a contract basis.
We believe we have some of the greatest minds in our business and will utilize this capability to expand our business to the benefits of the team and all stakeholders.
This document describes level zero and level one tests to measure the performance of Fourier transform mid-infrared spectrometers. Level zero tests involve routine checks that can be done in a few minutes to visually detect changes in instrument performance over time. Level zero tests include measuring reference spectra of an empty beam and polystyrene film, and comparing the results to previously stored reference spectra. Level one tests provide more quantitative data on various aspects of instrument performance.
Recently, a new high-sensitivity detector was introduced that provides improved UHPLC system performance and includes new features that improve workplace efficiency.
This presentation introduces this technology and provides a description of its use for impurity analysis. For more information, go to www.ssi.shimadzu.com or follow Shimadzu on Twitter @shimadzussi.
Thanks for viewing!
This document outlines a test to determine if any reaction exists between latex gloves, cleanroom wipers, and acetone solvent through qualitative FTIR analysis. Gloves, wipers, and acetone were agitated together and their weights measured before and after. Extracts were placed in sample bottles and sent for FTIR testing to identify any leached residues. The goal was to evaluate potential non-volatile residues from cleaning materials that could remain after cleaning.
Calibration - UV VIS Spectrophotometer, HPLC, Gas Chromatograph, IR spectroph...SELINA SRAVANTHI
Calibration of analytical instruments is important to ensure accurate measurements. It involves comparing instruments to more precise reference standards. Calibrating UV-Vis spectrophotometers involves checking wavelength accuracy using holmium filters, absorbance accuracy using potassium dichromate, stray light levels, resolution, and linearity. Calibrating IR spectrometers involves checking wavenumber accuracy using polystyrene, resolution, transmittance levels, linearity, and reproducibility. Calibrating fluorimeters involves setting excitation/emission wavelengths and adjusting the concentration readout using standards. Calibrating HPLCs involves checking flow rate accuracy and gradient performance using solvent mixtures.
Calibration of infrared (IR) spectroscopy ensures the instrument provides accurate measurements. The calibration process involves using a polystyrene film standard to produce an IR spectrum. The spectrum is compared to a reference standard to check if the strongest peak is within 95% of the maximum. If not, adjustments are made to correct the signal. Periodic calibration is needed to account for instrument drift over time and ensure precise results.
Spectrolytic has become the pioneer in the supply of cost effective, mid-infrared spectroscopy solutions, offering the lowest cost per measurement point. Spectrolytic’s product portfolio moves the powerful analytical technology of mid-infrared spectroscopy (FTIR) out of the laboratory into the field, providing real time analysis anywhere, anytime.
Spectrolytic GmbH develops a static FTIR spectrometer that uses a patented optical design without moving parts. This makes it faster, more robust, and suitable for portable applications compared to conventional FTIR spectrometers which use a moving mirror. The static FTIR can process all wavelengths in parallel at speeds up to 50Hz. It finds applications in areas like medical analysis, process monitoring, and analysis of fast moving samples due to its measurement speed, robustness, and accuracy.
Spectrolytic was founded with the aim of making spectroscopy solutions available to the masses and to broaden the view of usability.
Spectrolytic GmbH is a developer and supplier of infrared spectrometers and related solutions for a wide range of applications and markets. It also provides development and manufacturing services to third parties for both systems and solutions.
Spectrolytic GmbH has its registered office in Wernberg-Köblitz, Germany, and its operating HQ in Wackersdorf, Germany. The Companies design, manufacture (internally and/or externally) a range of spectroscopy systems for a number of market sectors including but not limited to industrial and consumer applications.
The Company also provide technology consulting, system design and development services, plus related manufacturing to customers on a contract basis.
We believe we have some of the greatest minds in our business and will utilize this capability to expand our business to the benefits of the team and all stakeholders.
This document describes level zero and level one tests to measure the performance of Fourier transform mid-infrared spectrometers. Level zero tests involve routine checks that can be done in a few minutes to visually detect changes in instrument performance over time. Level zero tests include measuring reference spectra of an empty beam and polystyrene film, and comparing the results to previously stored reference spectra. Level one tests provide more quantitative data on various aspects of instrument performance.
Wavelength accuracy is defined as the deviation of a measured wavelength from the known wavelength of an absorption or emission band. Wavelength accuracy and repeatability are important for UV/VIS instruments, as small deviations can cause errors in qualitative and quantitative analysis. Array-based instruments generally have better wavelength stability than scanning instruments, which have moving parts prone to misalignment. Various pharmacopeias specify wavelength accuracy requirements, with some applications requiring sub-nanometer accuracy. Regular calibration using reference standards like holmium oxide is needed to ensure wavelength accuracy is maintained over time.
Medical Laboratory technology Lab Manual for MLT students Vamsi kumar
MLT II lab manual for MLT students
Demonstration of working of spectrophotometer
Demonstration of maintenance of equipments and reagents
Sample formats for reporting test result
Demonstration of policies and procedures for infection control
Demonstration of mock diagnostic lab for learning & understanding patients right
Demonstration of mock environment to learn and understand conducive patient environment
Collection and handling of specimen for histopathology/cytopathology examination
Demonstration of working of Microtome
Demonstration of sharpening methods of microtome knife
Demonstration of tissue processing
Demonstration of PAP staining
Demonstration of PAS staining
Collection and handling of specimen for cytopathology examination
Demonstration of Mounting technique Demonstration of Mounting technique
Demonstration of maintaining record of inventory, test results etc
This document discusses UV-Visible spectrophotometry. It describes how spectrophotometers have evolved from colorimeters and the basic components and types of spectrophotometers. It also explains key concepts like the Beer-Lambert law and how absorbance relates to analyte concentration and path length. Different types of light sources, monochromators, sample chambers and detectors are outlined. Applications include identification of compounds, quality control, and calibration of spectrophotometers for parameters like wavelength accuracy and photometric accuracy using liquid and solid filters.
Handbook of Optical Filters for Fluorescence Microscopychromatechnology
This guide is a compilation of the principles and know-how that the engineers at Chroma Technology Corp use to design filters for a variety of fluorescence microscopes and applications, including wide-field microscopes, confocal microscopes, and applications involving simultaneous detection of multiple fluorescent probes. Also included is information on the terms used to describe and specify optical filters and practical information on how filters can affect the optical alignment of a microscope. Finally, the handbook ends with a glossary of terms that are italicized or in boldface in the text.
No single liquid chromatography (LC) detector delivers ideal results. Often with LC detectors one analyte responds more strongly than another, or may not respond at all. What is most desired is the ability to accurately measure a wide range of analytes with consistent response simultaneously.
Charged Aerosol detection (CAD) is a mass sensitive technique for determining levels of any non-volatile and many semi-volatile analytes after separation by liquid chromatography. This technique provides consistent analyte response independent of chemical characteristics and gives greater sensitivity over a wider dynamic range. An analytes response does not depend on optical properties, like with UV-vis absorbance, or the ability to ionize, as with mass spectrometry (MS). The presence of chromophoric groups, radiolabels, ionizable moieties, or chemical derivatization is needed for detection.
The document discusses charged aerosol detection, which can detect non-volatile and semi-volatile compounds that lack a chromophore or the ability to ionize. It compares charged aerosol detection to evaporative light scattering detection (ELSD). Charged aerosol detection has better sensitivity, linearity, and dynamic range than ELSD. It provides consistent detection of analytes independent of their chemical structure. The document presents several examples of applications using charged aerosol detection to analyze compounds such as adjuvants, glycans, carbohydrates, steviol glycosides, algal biofuels, and active pharmaceutical ingredients. It also describes using an inverse gradient to obtain a uniform response from charged aerosol detection when
This document discusses the technique of difference spectrophotometry and derivative spectrophotometry. It explains that these methods can improve the selectivity and accuracy of spectrophotometric analysis for samples containing absorbing interferents. Difference spectrophotometry works by measuring the difference in absorbance between two equimolar solutions with different chemical forms, while derivative spectrophotometry converts a normal absorption spectrum into its derivative to remove spectral interferences. Both techniques allow determination of a substance's spectrum that is unaffected by pH or other changes.
This document discusses the calibration of various analytical instruments used in pharmaceutical analysis. It begins with an introduction to calibration and the need for calibrating instruments. It then provides details on calibrating UV-Vis spectrophotometers, IR spectrophotometers, spectrofluorimeters, HPTLC, and gas chromatography. For each instrument, it describes the parameters checked during calibration such as wavelength accuracy, resolution, photometric accuracy, linearity, and acceptance criteria. The document aims to explain the calibration process for key analytical tools to ensure accurate measurements.
This document discusses molecular spectroscopy and spectrophotometry. It describes how a spectrophotometer works by measuring the intensity of light passing through a sample as a function of wavelength. Key components of a spectrophotometer include a light source, monochromator, cuvette containing the sample, and detector. The document also explains Beer's and Lambert's laws which relate absorbance to characteristics of the sample like concentration and path length. Colorimeters are also covered as devices that can determine concentration by measuring absorbance at specific wavelengths based on the Beer-Lambert law.
Calibration and validation of analytical instrumentsSolairajan A
This document discusses the calibration and validation of various analytical instruments used in pharmaceutical analysis. It provides details on calibrating UV-Vis spectrophotometers, IR spectrophotometers, spectrofluorimeters, HPLC, and GC. Calibration ensures instrument readings are accurate against standards, while validation confirms the instrument is correctly installed and operating as intended. The document outlines tests and acceptance criteria for evaluating characteristics like wavelength accuracy, resolution, noise, baseline flatness, sensitivity, flow rate, and linearity during calibration and validation of different analytical instruments.
Fluorescence spectroscopy analyzes fluorescence from a sample using light, usually ultraviolet light, to excite electrons in molecules of certain compounds causing them to emit light of a lower energy. Molecules have various electronic and vibrational energy levels, and fluorescence spectroscopy examines electronic state transitions. A photon excites a molecule to a higher vibrational state, which then loses energy and drops to the lowest excited state, emitting a photon of different energy upon returning to the ground state.
This document describes a study that compares the sensitivity of a single mode fiber optic sensor (FOS) to a conventional capacitive sensor (CS) for detecting partial discharge (PD) in transformer oil. PD occurs due to electrical breakdown in the oil and degrades the transformer insulation over time. Both sensors were immersed in an oil tank with high voltage electrodes to generate PD. The FOS detected acoustic emission from the PD, which modulated light in the fiber from a laser source. The CS detected electric fields from the PD. Analysis of the sensor signals in time and frequency domains found the FOS had a higher resolution (~9 dB) than the CS (~15 dB) for voltages over 15 kV, demonstrating it is a more
This document describes a standard practice for determining the activation spectrum of a material, which identifies the spectral regions of light that cause changes in the material's appearance and properties. It outlines two techniques: using sharp cut-on filters to expose the material to individual spectral bands simultaneously, and using a spectrograph to expose it to isolated narrow bands separately. The activation spectrum is specific to the light source used and provides information to help stabilize materials against degradation from certain wavelengths.
Ultra Performance Liquid Chromatography (UPLC) is an analytical technique that improves chromatographic resolution, speed, and sensitivity compared to traditional HPLC. It uses columns packed with smaller particles less than 2.5 μm. This allows for higher pressures, faster flow rates, and shorter run times. UPLC provides increased peak capacity and sensitivity for applications like metabolite identification, impurity profiling, and dissolution testing in pharmaceutical analysis and quality control.
The document discusses the qualification of analytical equipment. It describes the types of qualification which include design qualification, installation qualification, operational qualification, and performance qualification. It provides details on qualifying various analytical instruments such as FTIR, GC, and HPLC. Specific parameters to be tested during qualification are discussed for components like the inlet, oven, detector, autosampler, and others, along with typical acceptance criteria. The document emphasizes the importance of qualifying analytical equipment to ensure it is properly installed, operates correctly, and provides expected results.
This was a presentation by me for a Seminar For My Pharm. Analysis class. I have tried well to include possible things but haven't gone much in deep because it would be irrelevant as per syllabus. If any mistakes, Please do leave a comment
This document provides 10 best practices for testing electrosurgical units (ESUs) to ensure their performance and safety. It recommends adopting standardized test procedures, using additional test equipment like electrical safety analyzers and medical oscilloscopes, exercising caution with active electrodes, and performing comprehensive tests of power output, RF leakage currents, return electrode monitors, and inert gas parameters. It also suggests using test automation to quickly perform tests, document measurements, and archive long-term data. The document promotes choosing an ESU tester like the QA-ES II Electrosurgery Analyzer that can perform complete preventive maintenance and safety testing.
The document discusses UV-VIS spectroscopy. It introduces the technique, including principles such as the Beer-Lambert law. It describes the components of a spectrophotometer and various modes of analysis including quantitative analysis, kinetics measurements, and multi-component analysis. It also covers topics like method development and validation, including calibration procedures to control absorbance, limit stray light, and ensure proper resolution. The document provides an overview of the fundamentals and applications of UV-VIS spectroscopy.
performance and specifications of spectrophotometerPulak Das
Spectrophotometers measure the intensity of light at specific wavelengths to determine the concentration of compounds in solution. They consist of a light source, wavelength selector like a monochromator, cuvette to hold samples, photodetector like a photomultiplier tube, readout device, and data system. For accurate results, spectrophotometers must meet various performance specifications including wavelength accuracy checked using holmium oxide or didymium filters, low stray light verified with cutoff filters, linear detector response across concentration ranges, and photometric accuracy assessed using neutral density filters.
16 chapter 5 pharmaceutical formulation and its evaluationPCSIR
This document discusses the formulation and evaluation of herbal hair oils and creams. It describes the preparation methods for herbal hair oils using coconut oil as the base and ethyl acetate fractions of plant extracts. Four herbal hair oil formulations were prepared and evaluated for parameters like pH, viscosity, acid value, peroxide value and saponification value. An oil-in-water cream was also formulated using stearic acid as the emulsifier and plant extract fractions. The cream formulations were evaluated for properties like appearance, pH, viscosity and emulsion type. Stability studies including tests for globule size, phase separation and moisture absorption were also conducted on the cream formulations.
This document summarizes the history of education policy making in Pakistan and analyzes reasons for the failure of policy implementation. It discusses conventional explanations for failures, such as unclear goals, lack of political commitment, and issues with governance. It also argues that a neuro-cognitive perspective is needed to understand how individuals make sense of policies and the cognitive constraints on learning and behavior change. Accounting for both conventional factors and cognitive constraints could help formulate policies more likely to achieve desired outcomes. The document uses examples from Pakistan's education policies to support its analysis of challenges with policy implementation.
Wavelength accuracy is defined as the deviation of a measured wavelength from the known wavelength of an absorption or emission band. Wavelength accuracy and repeatability are important for UV/VIS instruments, as small deviations can cause errors in qualitative and quantitative analysis. Array-based instruments generally have better wavelength stability than scanning instruments, which have moving parts prone to misalignment. Various pharmacopeias specify wavelength accuracy requirements, with some applications requiring sub-nanometer accuracy. Regular calibration using reference standards like holmium oxide is needed to ensure wavelength accuracy is maintained over time.
Medical Laboratory technology Lab Manual for MLT students Vamsi kumar
MLT II lab manual for MLT students
Demonstration of working of spectrophotometer
Demonstration of maintenance of equipments and reagents
Sample formats for reporting test result
Demonstration of policies and procedures for infection control
Demonstration of mock diagnostic lab for learning & understanding patients right
Demonstration of mock environment to learn and understand conducive patient environment
Collection and handling of specimen for histopathology/cytopathology examination
Demonstration of working of Microtome
Demonstration of sharpening methods of microtome knife
Demonstration of tissue processing
Demonstration of PAP staining
Demonstration of PAS staining
Collection and handling of specimen for cytopathology examination
Demonstration of Mounting technique Demonstration of Mounting technique
Demonstration of maintaining record of inventory, test results etc
This document discusses UV-Visible spectrophotometry. It describes how spectrophotometers have evolved from colorimeters and the basic components and types of spectrophotometers. It also explains key concepts like the Beer-Lambert law and how absorbance relates to analyte concentration and path length. Different types of light sources, monochromators, sample chambers and detectors are outlined. Applications include identification of compounds, quality control, and calibration of spectrophotometers for parameters like wavelength accuracy and photometric accuracy using liquid and solid filters.
Handbook of Optical Filters for Fluorescence Microscopychromatechnology
This guide is a compilation of the principles and know-how that the engineers at Chroma Technology Corp use to design filters for a variety of fluorescence microscopes and applications, including wide-field microscopes, confocal microscopes, and applications involving simultaneous detection of multiple fluorescent probes. Also included is information on the terms used to describe and specify optical filters and practical information on how filters can affect the optical alignment of a microscope. Finally, the handbook ends with a glossary of terms that are italicized or in boldface in the text.
No single liquid chromatography (LC) detector delivers ideal results. Often with LC detectors one analyte responds more strongly than another, or may not respond at all. What is most desired is the ability to accurately measure a wide range of analytes with consistent response simultaneously.
Charged Aerosol detection (CAD) is a mass sensitive technique for determining levels of any non-volatile and many semi-volatile analytes after separation by liquid chromatography. This technique provides consistent analyte response independent of chemical characteristics and gives greater sensitivity over a wider dynamic range. An analytes response does not depend on optical properties, like with UV-vis absorbance, or the ability to ionize, as with mass spectrometry (MS). The presence of chromophoric groups, radiolabels, ionizable moieties, or chemical derivatization is needed for detection.
The document discusses charged aerosol detection, which can detect non-volatile and semi-volatile compounds that lack a chromophore or the ability to ionize. It compares charged aerosol detection to evaporative light scattering detection (ELSD). Charged aerosol detection has better sensitivity, linearity, and dynamic range than ELSD. It provides consistent detection of analytes independent of their chemical structure. The document presents several examples of applications using charged aerosol detection to analyze compounds such as adjuvants, glycans, carbohydrates, steviol glycosides, algal biofuels, and active pharmaceutical ingredients. It also describes using an inverse gradient to obtain a uniform response from charged aerosol detection when
This document discusses the technique of difference spectrophotometry and derivative spectrophotometry. It explains that these methods can improve the selectivity and accuracy of spectrophotometric analysis for samples containing absorbing interferents. Difference spectrophotometry works by measuring the difference in absorbance between two equimolar solutions with different chemical forms, while derivative spectrophotometry converts a normal absorption spectrum into its derivative to remove spectral interferences. Both techniques allow determination of a substance's spectrum that is unaffected by pH or other changes.
This document discusses the calibration of various analytical instruments used in pharmaceutical analysis. It begins with an introduction to calibration and the need for calibrating instruments. It then provides details on calibrating UV-Vis spectrophotometers, IR spectrophotometers, spectrofluorimeters, HPTLC, and gas chromatography. For each instrument, it describes the parameters checked during calibration such as wavelength accuracy, resolution, photometric accuracy, linearity, and acceptance criteria. The document aims to explain the calibration process for key analytical tools to ensure accurate measurements.
This document discusses molecular spectroscopy and spectrophotometry. It describes how a spectrophotometer works by measuring the intensity of light passing through a sample as a function of wavelength. Key components of a spectrophotometer include a light source, monochromator, cuvette containing the sample, and detector. The document also explains Beer's and Lambert's laws which relate absorbance to characteristics of the sample like concentration and path length. Colorimeters are also covered as devices that can determine concentration by measuring absorbance at specific wavelengths based on the Beer-Lambert law.
Calibration and validation of analytical instrumentsSolairajan A
This document discusses the calibration and validation of various analytical instruments used in pharmaceutical analysis. It provides details on calibrating UV-Vis spectrophotometers, IR spectrophotometers, spectrofluorimeters, HPLC, and GC. Calibration ensures instrument readings are accurate against standards, while validation confirms the instrument is correctly installed and operating as intended. The document outlines tests and acceptance criteria for evaluating characteristics like wavelength accuracy, resolution, noise, baseline flatness, sensitivity, flow rate, and linearity during calibration and validation of different analytical instruments.
Fluorescence spectroscopy analyzes fluorescence from a sample using light, usually ultraviolet light, to excite electrons in molecules of certain compounds causing them to emit light of a lower energy. Molecules have various electronic and vibrational energy levels, and fluorescence spectroscopy examines electronic state transitions. A photon excites a molecule to a higher vibrational state, which then loses energy and drops to the lowest excited state, emitting a photon of different energy upon returning to the ground state.
This document describes a study that compares the sensitivity of a single mode fiber optic sensor (FOS) to a conventional capacitive sensor (CS) for detecting partial discharge (PD) in transformer oil. PD occurs due to electrical breakdown in the oil and degrades the transformer insulation over time. Both sensors were immersed in an oil tank with high voltage electrodes to generate PD. The FOS detected acoustic emission from the PD, which modulated light in the fiber from a laser source. The CS detected electric fields from the PD. Analysis of the sensor signals in time and frequency domains found the FOS had a higher resolution (~9 dB) than the CS (~15 dB) for voltages over 15 kV, demonstrating it is a more
This document describes a standard practice for determining the activation spectrum of a material, which identifies the spectral regions of light that cause changes in the material's appearance and properties. It outlines two techniques: using sharp cut-on filters to expose the material to individual spectral bands simultaneously, and using a spectrograph to expose it to isolated narrow bands separately. The activation spectrum is specific to the light source used and provides information to help stabilize materials against degradation from certain wavelengths.
Ultra Performance Liquid Chromatography (UPLC) is an analytical technique that improves chromatographic resolution, speed, and sensitivity compared to traditional HPLC. It uses columns packed with smaller particles less than 2.5 μm. This allows for higher pressures, faster flow rates, and shorter run times. UPLC provides increased peak capacity and sensitivity for applications like metabolite identification, impurity profiling, and dissolution testing in pharmaceutical analysis and quality control.
The document discusses the qualification of analytical equipment. It describes the types of qualification which include design qualification, installation qualification, operational qualification, and performance qualification. It provides details on qualifying various analytical instruments such as FTIR, GC, and HPLC. Specific parameters to be tested during qualification are discussed for components like the inlet, oven, detector, autosampler, and others, along with typical acceptance criteria. The document emphasizes the importance of qualifying analytical equipment to ensure it is properly installed, operates correctly, and provides expected results.
This was a presentation by me for a Seminar For My Pharm. Analysis class. I have tried well to include possible things but haven't gone much in deep because it would be irrelevant as per syllabus. If any mistakes, Please do leave a comment
This document provides 10 best practices for testing electrosurgical units (ESUs) to ensure their performance and safety. It recommends adopting standardized test procedures, using additional test equipment like electrical safety analyzers and medical oscilloscopes, exercising caution with active electrodes, and performing comprehensive tests of power output, RF leakage currents, return electrode monitors, and inert gas parameters. It also suggests using test automation to quickly perform tests, document measurements, and archive long-term data. The document promotes choosing an ESU tester like the QA-ES II Electrosurgery Analyzer that can perform complete preventive maintenance and safety testing.
The document discusses UV-VIS spectroscopy. It introduces the technique, including principles such as the Beer-Lambert law. It describes the components of a spectrophotometer and various modes of analysis including quantitative analysis, kinetics measurements, and multi-component analysis. It also covers topics like method development and validation, including calibration procedures to control absorbance, limit stray light, and ensure proper resolution. The document provides an overview of the fundamentals and applications of UV-VIS spectroscopy.
performance and specifications of spectrophotometerPulak Das
Spectrophotometers measure the intensity of light at specific wavelengths to determine the concentration of compounds in solution. They consist of a light source, wavelength selector like a monochromator, cuvette to hold samples, photodetector like a photomultiplier tube, readout device, and data system. For accurate results, spectrophotometers must meet various performance specifications including wavelength accuracy checked using holmium oxide or didymium filters, low stray light verified with cutoff filters, linear detector response across concentration ranges, and photometric accuracy assessed using neutral density filters.
16 chapter 5 pharmaceutical formulation and its evaluationPCSIR
This document discusses the formulation and evaluation of herbal hair oils and creams. It describes the preparation methods for herbal hair oils using coconut oil as the base and ethyl acetate fractions of plant extracts. Four herbal hair oil formulations were prepared and evaluated for parameters like pH, viscosity, acid value, peroxide value and saponification value. An oil-in-water cream was also formulated using stearic acid as the emulsifier and plant extract fractions. The cream formulations were evaluated for properties like appearance, pH, viscosity and emulsion type. Stability studies including tests for globule size, phase separation and moisture absorption were also conducted on the cream formulations.
This document summarizes the history of education policy making in Pakistan and analyzes reasons for the failure of policy implementation. It discusses conventional explanations for failures, such as unclear goals, lack of political commitment, and issues with governance. It also argues that a neuro-cognitive perspective is needed to understand how individuals make sense of policies and the cognitive constraints on learning and behavior change. Accounting for both conventional factors and cognitive constraints could help formulate policies more likely to achieve desired outcomes. The document uses examples from Pakistan's education policies to support its analysis of challenges with policy implementation.
This document summarizes information about the antisemitic forgery known as "The Protocols of the Learned Elders of Zion". It explains that the document was not actually written by Jewish people, but was instead plagiarized from earlier works and propagated by Russian secret police to strengthen the weak czar and blame Jews for reforms. While initially used to incite pogroms in Russia in 1905, the forgery was later spread more widely and helped justify the Nazis' genocide against Jews. A Russian court in the 1920s ruled that the Protocols were an antisemitic forgery, but it continued to be widely circulated and believed until being fully debunked in the 1920s.
This study examines masculinity in Pashto folk poetry, specifically the genre of "Gharra", through analysis of folk poetry and interviews. Two case studies of tribal conflicts are presented. Both began from small disputes but escalated as each side sought to avenge losses and defend their honor. Folk poetry such as "Gharra" played a role in fueling passions for revenge and asserting bravery. The study finds masculinity and defending one's honor are core aspects of Pashtun identity and tribalism that folk poetry has traditionally reinforced during conflicts. However, oral traditions are weakening with modern influences, though much cultural history remains preserved in folk genres.
Analytical characterization of fatty acids composition of datura albaPCSIR
- The document analyzes the fatty acid composition of Datura alba seed oil using gas chromatography mass spectrometry (GC-MS).
- A total of 15 different fatty acids were identified and quantified, with linoleic acid found to have the highest concentration at 16.22%. Other major fatty acids identified were palmitic acid (6.59%), oleic acid (5.41%), and stearic acid (1.35%).
- This work provides the first analytical characterization of the fatty acid composition of D. alba seed oil using GC-MS, which can help explore its potential pharmacological importance.
In vitro phytochemical, antibacterial and antifungal activities of leaves, st...PCSIR
This study investigated the phytochemical and antimicrobial activities of extracts from the leaves, stems, and roots of Adiantum capillus veneris. Phytochemical analysis revealed the presence of flavonoids, alkaloids, tannins, saponins, and other compounds. Water, methanol, and ethanol extracts showed significant antibacterial activity against multidrug-resistant bacterial strains isolated from clinical samples, as well as antifungal activity against medically important fungi. Fourier transform infrared spectroscopy identified compounds such as aldehydes, amides, alcohols, and carboxylic acids in the extracts. This research concluded that A. capillus veneris extracts have valuable phytochemicals and significant
Micro propagation of stevia rebaudiana bertoniPCSIR
This document summarizes a study on the micropropagation of Stevia rebaudiana Bertoni, an exotic medicinal plant, through root explants. Researchers found that surface sterilizing root explants with 0.25% mercury chloride solution eliminated contamination and mortality. Shoots were induced on root explants cultured on MS medium supplemented with 1.25mg/L BAP, resulting in 59.5% induction and 3.05cm shoot length. A combination of 1.25mg/L BAP and 0.5mg/L TDZ achieved the highest shoot induction of 89.5% and length of 3.75cm. Subculturing induced multiple shoot proliferation. Roots were induced through culturing micro
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...
D16128~
1. U.S. and European Pharmacopoeias and
UV-Visible Spectrophotometers
Michael W. Allen, Ph.D., Thermo Fisher Scientific, Madison, WI, USA
Introduction
UV-Visible spectrophotometers are versatile instruments
that measure a variety of different samples in diverse
laboratory settings. In some laboratories, instruments
are regulated by agencies such as the Food and Drug
Administration (FDA) and the European Medicines
Agency (EMEA). Thermo Scientific products provide a
comprehensive suite of resources to help your laboratory
achieve compliance with regulatory agencies. This includes
software enabling 21 CFR Part 11 compliance to satisfy
the FDA requirements for electronic records and electronic
signatures, traceable certified reference materials produced
in our own ISO/IEC 17025 accredited standards laboratory,
and rigorous validation documentation to help your
laboratory achieve and maintain compliance.
Installation qualification (IQ), operational
qualification (OQ), and performance verification (PV) tests
are performed using certified reference materials (CRMs).
CRMs are traceable to primary standards recognized by
the National Institutes of Science and Technology (NIST)
or the National Physical Laboratory (NPL). Traceability
ensures equivalent measurements are made regardless of
the instrument or the region of the world where the
measurement is made. ISO/IEC 17025 accreditation
provides the assurance that our standards laboratory
always uses the appropriate processes and procedures. We
are the only UV-Visible spectrophotometer manufacturer
to have a fully accredited laboratory that produces
standards traceable to both NIST and NPL.
Documents like the U.S. Pharmacopoeia (USP), the
European Pharmacopoeia (EP), the British Pharmacopoeia
(BP), the Japanese Pharmacopeia and the Australian TGA
provide specific testing protocols and, in some cases,
specifications for instrument performance. These
guidelines, in conjunction with the Thermo Scientific
UV Validator, help your laboratory achieve and maintain
regulatory compliance. The UV Validator guides you
step-by-step through the process of IQ and OQ, writing
standard operating procedures (SOPs), and storing records
in one location for easy access during an audit.
This application note will focus on the requirements
for UV-Visible spectrophotometers specified in the USP
and EP. It is designed to help you understand what is and
is not required in the individual Pharmacopoeias and
specifically what reference material is needed to perform
each test. Since both the USP and EP frequently allow
alternative methods for testing, a list of CRMs and
re-calibration services available is also supplied.
USP and EP Specifications for UV-Visible
Spectrophotometers
Section 851 of the USP describes the requirements for
UV-Visible spectrophotometers. Additional specifications
are provided in some of the individual monographs that
use UV-Visible spectrophotometers to perform the assay,
such as the quantification of Lycopene [PF30(2)]. Likewise,
the requirements for UV-Visible spectrophotometers are
given in section 2.2.25 of the EP. The EP details some
specific performance requirements in this section, such as
the permitted tolerance for wavelength accuracy. However,
like the USP, additional specifications are found in the
individual monographs of the EP.
It can be inferred from both the USP and EP that your
instrument must meet the general requirements specified
in the instrument specific section and the performance
expectation of the individual monographs. Therefore, if
you are performing an assay given in a specific monograph,
you are bound by the tolerance given in that monograph.
Key Words
• Certified
Reference
Materials
• European
Pharmacopoeia
• Operational
Qualification (OQ)
• Performance
Verification
• Regulatory
Compliance
• U.S.
Pharmacopoeia
Application
Note: 51111
2. General Test Descriptions
Photometric Accuracy, or absorbance accuracy, is the
deviation between the absorption value measured on a
spectrophotometer and the precisely known absorbance
value of a traceable standard. Photometric accuracy is
extremely important when the extinction coefficient of
an analyte is being determined or when single point
quantification measurements are performed.
Resolution is related to the physical slit width of the
spectrophotometer, which in turn determines the spectral
bandwidth (SBW) of the instrument. By definition,
resolution is the ability to resolve two adjacent peaks.
Therefore, resolution and spectral bandwidth are not
identical measurements. Figure 1 shows the variation
in the toluene in hexane test on a Thermo Scientific
Evolution™ 600 instrument as a function of SBW. From
Table 1 you can see the strong dependence of the SBW on
the ratio obtained from the peak and the valley of the test.
It is important to remember that as the physical and
spectral bandwidth decrease, so does the energy throughput,
thus the signal-to-noise ratio of the measurement is lower.
It is always recommended that the SBW of the instrument
not exceed 10% of the natural bandwidth of the
absorption band.
Stray Light is stray radiant energy present in the
spectrophotometer. Instrumental stray light evaluates the
efficiency of the instrument, which is influenced by
scattering, higher order diffraction, and the performance
of optical components and the detector(s). Stray light
limits instrument performance at high absorbance or low
transmittance values. For more information, request Thermo
Scientific Technical Note 51170, Stray Light – Measurement
and Effect on Performance in UV-Visible Spectroscopy.
Wavelength Accuracy can be defined as the discrepancy
between the wavelength value reported by the instrument
for a peak and that of a precisely known peak. This test
effectively evaluates the performance of the moving
mechanical components responsible for positioning the
monochromator. While these components are very stable,
they are susceptible to the effects of thermal changes and
vibration. For more information, request Thermo Scientific
Technical Note 51171, Wavelength Accuracy – Measurement
and Effect on Performance in UV-Visible Spectroscopy.
The sections that follow describe the general
requirements of the EP given in section 2.2.25 and the
USP in section 851.
European Pharmacopeia Specifications
Section 2.2.25 entitled Absorption Spectrophotometry,
Ultraviolet and Visible of the EP details how to perform
UV-Visible absorption measurements. This section also
describes the individual performance verification tests and
provides some specific instrument performance specifications.
Detailed specifications can also be found in the individual
monographs.
Apparatus. This first section of the EP defines the
instruments that are appropriate for absorption
measurements. It states that the instruments must be
“capable of producing monochromatic radiation in the
range of 200 nm to 800 nm” and have a “device
suitable for measuring the absorbance”, i.e. a detector.
This is a general requirement and is satisfied by all
Thermo Scientific UV-Visible spectrophotometers.
Control of Wavelengths or Wavelength Accuracy. This
section describes the verification of the wavelength scale.
The EP specifies four methods of determining wavelength
accuracy: (1) the absorption maxima of a holmium
perchlorate solution, (2) the emission line of a hydrogen
discharge lamp, (3) the emission line of a deuterium
discharge lamp, and (4) the emission lines of a mercury
vapor lamp. A table of absorption maxima for each of
these methods is given in Table 2. The EP states, “the
permitted tolerance is ± 1 nm for the ultraviolet range
and ± 3 nm for the visible.” This section also states that,
“[s]uitable certified reference materials may also be used.”
This requirement is satisfied or exceeded by all Thermo
Scientific UV-Visible spectrophotometers.
Figure 1: The toluene in hexane performance verification test at various
spectral bandwidths. Scans at 0.2 nm (blue), 0.5 nm (yellow), 1.0 (green),
1.5 (red), and 2.0 (black) are shown. Typical ratios are shown in Table 1.
SBW (nm) 0.5 1.0 1.5 2.0 3.0
Ratio 2.5 2.1 1.6 1.4 1.0
Table 1: Nominal minimum/maximum absorbance ratios of the toluene in
hexane test as a function of spectral bandwidth (SBW)
3. Control of Absorbance. This section describes the
verification of the absorbance scale, also referred to as
photometric accuracy or absorbance accuracy. The
recommended method of verifying photometric accuracy
is a solution of potassium dichromate. The EP gives
recommendations on the appropriate solvent and
concentrations for the preparation of dichromate solutions.
The EP states, “the tolerance for the absorption is ± 0.01.”
This section also states that, “suitable certified reference
materials may also be used.” Solutions of potassium
dichromate in far-UV sealed cuvettes are appropriate for
performing this test and are available from Thermo Scientific.
More information is provided in the CRMs sections on the
following pages. This requirement is satisfied or exceeded
by all Thermo Scientific UV-Visible spectrophotometers.
Limit of Stray Light. This section describes the
verification of stray light. The recommended method of
verifying stray light is a 12 g/L solution of potassium
chloride. The absorbance of this solution in a 1 cm cell
should be “greater than 2.0 at 198 nm when compared
with water as compensation liquid.” This section also
states that, “[s]uitable certified reference materials may
also be used.” Solutions of potassium chloride in far-UV
sealed cuvettes are available from Thermo Scientific. More
information is provided in the CRMs sections on the
following pages. This requirement is satisfied or exceeded
by all Thermo Scientific UV-Visible spectrophotometers.
Resolution. This section defines the procedure for
testing the resolution of the spectrophotometer, when
prescribed in a specific monograph. The recommended
method of testing is a 0.02% (v/v) percent solution of
toluene in hexane. The minimum ratio of the absorbance at
266 nm to 269 nm is stated in the monograph. This section
also states that, “suitable certified reference materials may
also be used.” Since the individual monographs define the
appropriate limits of this test, please refer to the individual
instrument specifications to determine the best instrument
for your analysis. Currently, there are no monographs in
the EP that specify a resolution requirement for a Visible
or UV-Visible spectrophotometer. Typically a spectral
bandwidth less than 2.0 nm is required to meet the British
Pharmacopoeia (BP) specification. The Evolution 600,
Evolution 300, Evolution 60 and the GENESYS™ 6
spectrophotometers meet or exceed this requirement.
Variable Slit Widths. A recent addition to the EP, this
section defines the use of an instrument with variable
slit-widths or spectral bandwidth (SBW). If using an
instrument with a variable slit width, such as the
Evolution 300 or Evolution 600 spectrophotometer, the
“slit-width must be small compared with the half-width of
the absorption band…” Typically, the half-width of the
peak being analyzed should be greater than 10 times the
SBW. This means an SBW of 1.0 nm should be used to
analyze peaks greater than 10 nm wide at half height. The
standard continues “…it [slit-width] must be as large as
possible to obtain a high value of I0.” With this statement,
the EP suggests that the largest possible SBW be used for
quantitative analysis.
U. S. Pharmacopeia Specifications
Section 851 entitled Spectrophotometry and Light
Scattering of the USP details how to perform UV-Visible
absorption measurements. This section also describes the
individual performance verification tests and the
recommended standards for performing these tests;
however, it provides no specific instrument performance
specifications. These instrument specifications are found
in the individual monographs for the assays.
Accuracy of Calibration - wavelength scale. This
section describes the verification of the wavelength scale,
also referred to as wavelength accuracy. The USP states,
“the best single source of UV and visible calibration is
the quartz-mercury arc.” The section then continues by
stating that, “a hydrogen discharge lamp may also be
used.” A table of calibration wavelengths for both lamps
is given in Table 3.
A mercury lamp accessory is available for the
Evolution 300 and Evolution 600 spectrophotometers.
Because the emission lines from the mercury lamp are
fundamental properties of the element, there is no inherent
calibration or certification necessary with this standard.
Additionally, this accessory provides the best method for
verifying wavelength accuracy as stated in the USP. Moreover,
the Mercury Lamp accessory also allows you to calibrate
the wavelength scale of the instrument exactly as it was
calibrated at the factory. This saves the cost of a service
call should re-calibration be necessary for any reason.
Holmium
Perchlorate Mercury Vapor Lamp Hydrogen Lamp Deuterium Lamp
Solution (nm) (nm)* (nm) (nm)
241.15 253.7 404.66 486.1 486.0
287.15 302.25 435.83
361.5 313.16 546.07
536.3 334.15 576.96
365.48 579.07
* The Evolution 300/600 Mercury Lamp Accessory allows automated
testing of the lines shown in bold print. Other lines are easily tested
with manual scans.
Table 2: Absorption maxima for EP standards (taken from Table 2.2.25.-1)
Quartz Mercury Arc Hydrogen Lamp
(nm)* (nm)
253.7 365.48 486.13
302.25 404.66 656.28
313.16 435.83
334.15
* The Evolution 300/600 Mercury Lamp Accessory allows automated
testing of the lines shown in bold print. Other lines are easily tested
with manual scans.
Table 3: Absorption maxima for USP wavelength accuracy standards
4. If continuous sources are not used, the USP specifies
a specific NIST reference material, SRM 2034, a certified
holmium oxide solution. Figure 2 shows the peaks of a
solution of holmium oxide in perchorlic acid, a test used
to verify wavelength accuracy.
The only rigid specification given in section 851 of the
USP regarding wavelength accuracy is, “…comparisons
[should] be made at the wavelength at which peak
absorption occurs. Should this differ by more than ± 1 nm
from the wavelengths specified in the individual monograph,
re-calibration of the instrument may be indicated.” This
specification is located in a paragraph discussing the good
practices for spectrophotometric measurements and does
not appear in the section discussing wavelength accuracy
tests. Some have inferred that this statement indicates a
resolution of 1 nm is a requirement of the USP, however,
it is merely a best practice suggestion for performing
wavelength calibrations.
Accuracy of Calibration – Photometric Scale. This
section describes the verification of the absorbance scale,
also referred to as photometric accuracy. Here the USP
simply states, “a number of standard inorganic glass filters
as well as standards solutions of known transmittances such
as… potassium dichromate are available.” Here the USP
references two specific NIST publications for SRM 930e and
SRM 931e, these documents detail the use of liquid and
glass filters for making photometric accuracy measurements.
Stray Light. No specification for stray light is given in
Section 851 of the USP.
Resolution. No specification for resolution is given in
Section 851 of the USP.
Thermo Scientific Certified Reference Materials
We maintain an ISO/IEC 17025 accredited standards
laboratory in Cambridge, UK. This laboratory allows us
to provide NIST and NPL traceable CRMs. Having a
NIST and NPL traceable laboratory saves valuable time
by decreasing the lead time required to receive traceable
standards. Additionally, this laboratory provides
recalibration services for many standards, regardless of
the original manufacturer.
The Evolution 300 and Evolution 600 instruments
feature an optional mercury lamp accessory. This
accessory allows not only for verification of wavelength
accuracy, but also allows the user to perform a complete
re-calibration of the instrument if necessary. The Mercury
Lamp tests performance and offers the ability to perform
a wavelength calibration exactly as it is performed in the
factory, all without a service call.
Information on our complete line of CRMs is provided
in the chart on the following page. Please contact us if
you have any additional questions regarding your
particular application.
Figure 2: The peaks of a solution of holmium oxide in perchloric acid solution.
The scan was acquired on a GENESYS 6 spectrophotometer using
VISIONlite™ software.