UV-Visible Spectrometry is a technique used to analyze how molecules interact with light in the UV-Visible region. It works based on Beer's Law, where the absorbance of a solution is directly proportional to concentration and path length. The key components of a UV-Vis spectrometer are a radiation source, monochromator, sample cells, and detectors. It can be used for structure elucidation, quantitative analysis, detection of impurities, and studying chemical kinetics. Larger conjugated systems absorb at longer wavelengths with higher intensities. Solvents and functional groups can also impact absorption spectra.
Spectrofluorimetry or fluorimetry (www.Redicals.com)Goa App
The term fluorescence comes from the mineral fluorspar (calcium fluoride) when Sir George G. Stokes observed in 1852 that fluorspar would give off visible light (fluoresce) when exposed to electromagnetic radiation in the ultraviolet wavelength.
UV -Vis Spectrophotometry- Principle, Theory, Instrumentation and Application...Dr. Amsavel A
UV -Vis Spectrophotometry- Principle, Theory, Instrumentation and Application in Pharmaceutical Industry Dr. A. Amsavel.
UV &Visible Spectroscopy-Absorption Theory
Electronic Transitions
Beer- Lambert Law
Chromophores & Auxochrome
Factors Influence the Absorption
UV-Vis Spectrophotometer-Instrumentation
Operation of the Spectrophotometer
Qualification & Calibration
Application
Spectrofluorimetry or fluorimetry (www.Redicals.com)Goa App
The term fluorescence comes from the mineral fluorspar (calcium fluoride) when Sir George G. Stokes observed in 1852 that fluorspar would give off visible light (fluoresce) when exposed to electromagnetic radiation in the ultraviolet wavelength.
UV -Vis Spectrophotometry- Principle, Theory, Instrumentation and Application...Dr. Amsavel A
UV -Vis Spectrophotometry- Principle, Theory, Instrumentation and Application in Pharmaceutical Industry Dr. A. Amsavel.
UV &Visible Spectroscopy-Absorption Theory
Electronic Transitions
Beer- Lambert Law
Chromophores & Auxochrome
Factors Influence the Absorption
UV-Vis Spectrophotometer-Instrumentation
Operation of the Spectrophotometer
Qualification & Calibration
Application
the presentation gives knowledge about principle or fluorometry, factors that affect fluorescence including quenching instruments used in fluorometry, and the applications of fluorometry. added references in the end for more knowledge.
Hyphenated technique is a combination or coupling of two analytical techniques with the help of proper interface.
In this presentation Hyphenated techniques-LC-MS/MS, GC-MS/MS, HPTLC-MS has been discussed
the presentation gives knowledge about principle or fluorometry, factors that affect fluorescence including quenching instruments used in fluorometry, and the applications of fluorometry. added references in the end for more knowledge.
Hyphenated technique is a combination or coupling of two analytical techniques with the help of proper interface.
In this presentation Hyphenated techniques-LC-MS/MS, GC-MS/MS, HPTLC-MS has been discussed
http://www.redicals.com
The spectrophotometer technique is to measures light intensity as a function of wavelength.
• Measures the light that passes through a liquid sample
• Spectrophotometer gives readings in Percent Transmittance (%T) and in Absorbance (A)
Main Points of UV and IR spectroscopy BY PuttamreddykavyasriKavyasriPuttamreddy
uv spectroscopy, theory of UV spectroscopy, electron transitions,
beer's law, lambert's law, beer lamberts law, instrumentation of UV spectroscopy, solvent effect on UV analysis, choice of solvent , solvent effect , chromophore, auxochrome, IR spectroscopy, principle of IR spectroscopy, applications of IR, applications of UV, analysis subjects, pharmaceutical analysis M.pharm 1 year, 1 year
The detailed information of UV Visible Spectroscopy, it includes the information regarding electronic transitions, Electromagnetic radiations, Various shifts.
UV - Visible Spectroscopy detailed information is included .The Spectroscopy study provide the information and the absorbance as well the concentration of the drugs is studied.
Similar to UV visible Specrosopy and applications (20)
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Micro RNA genes and their likely influence in rice (Oryza sativa L.) dynamic ...Open Access Research Paper
Micro RNAs (miRNAs) are small non-coding RNAs molecules having approximately 18-25 nucleotides, they are present in both plants and animals genomes. MiRNAs have diverse spatial expression patterns and regulate various developmental metabolisms, stress responses and other physiological processes. The dynamic gene expression playing major roles in phenotypic differences in organisms are believed to be controlled by miRNAs. Mutations in regions of regulatory factors, such as miRNA genes or transcription factors (TF) necessitated by dynamic environmental factors or pathogen infections, have tremendous effects on structure and expression of genes. The resultant novel gene products presents potential explanations for constant evolving desirable traits that have long been bred using conventional means, biotechnology or genetic engineering. Rice grain quality, yield, disease tolerance, climate-resilience and palatability properties are not exceptional to miRN Asmutations effects. There are new insights courtesy of high-throughput sequencing and improved proteomic techniques that organisms’ complexity and adaptations are highly contributed by miRNAs containing regulatory networks. This article aims to expound on how rice miRNAs could be driving evolution of traits and highlight the latest miRNA research progress. Moreover, the review accentuates miRNAs grey areas to be addressed and gives recommendations for further studies.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Diabetes is a rapidly and serious health problem in Pakistan. This chronic condition is associated with serious long-term complications, including higher risk of heart disease and stroke. Aggressive treatment of hypertension and hyperlipideamia can result in a substantial reduction in cardiovascular events in patients with diabetes 1. Consequently pharmacist-led diabetes cardiovascular risk (DCVR) clinics have been established in both primary and secondary care sites in NHS Lothian during the past five years. An audit of the pharmaceutical care delivery at the clinics was conducted in order to evaluate practice and to standardize the pharmacists’ documentation of outcomes. Pharmaceutical care issues (PCI) and patient details were collected both prospectively and retrospectively from three DCVR clinics. The PCI`s were categorized according to a triangularised system consisting of multiple categories. These were ‘checks’, ‘changes’ (‘change in drug therapy process’ and ‘change in drug therapy’), ‘drug therapy problems’ and ‘quality assurance descriptors’ (‘timer perspective’ and ‘degree of change’). A verified medication assessment tool (MAT) for patients with chronic cardiovascular disease was applied to the patients from one of the clinics. The tool was used to quantify PCI`s and pharmacist actions that were centered on implementing or enforcing clinical guideline standards. A database was developed to be used as an assessment tool and to standardize the documentation of achievement of outcomes. Feedback on the audit of the pharmaceutical care delivery and the database was received from the DCVR clinic pharmacist at a focus group meeting.
2. T = I0 / It
Transmittance T is a ratio of intensity of transmitted light
to that of the incident light.
A = log I0 / It
The more general equation can be written as follows:
A = log I0 / It = log 1/ T = – log T = abc = εbc
The molar absorption coefficient is a measurement of
how strongly a substance absorbs light.
The larger its value, the greater the absorption
Beer's and Lambert's Law
3.
4. INSTRUMENTATION
Instruments for measuring the absorption of U.V. or visible
radiation are made up of the following components;
1. Sources (UV and visible)
2. filter or monochromator
3. Sample containers or sample cells
4. Detector
5. Radiation source
It is important that the power of the radiation source does not change
abruptly over its wavelength range.
The electrical excitation of deuterium or hydrogen at low pressure
produces a continuous UV spectrum
The mechanism for this involves formation of an excited molecular species,
which breaks up to give two atomic species and an ultraviolet photon
Both Deuterium and Hydrogen lamps emit radiation in the range 160 - 375
nm
Quartz windows must be used in these lamps, and quartz cuvettes must be
used, because glass absorbs radiation of wavelengths less than 350 nm.
6. Various UV radiation sources
a. Deuterium lamp
b. Hydrogen lamp
c. Tungsten lamp
d. Xenon discharge lamp
e. Mercury arc lamp
Various Visible radiation sources
a. Tungsten lamp
b. Mercury vapour lamp
c. Carbonone lamp
7. Filters or monochromators
All monochromators contain the following component parts;
• An entrance slit
• A collimating lens
• A dispersing device (a prism or a grating)
• A focusing lens
• An exit slit
Steps Involved
a. Polychromatic radiation enters the monochromator through the entrance slit.
b. The beam is collimated, and then strikes the dispersing element at an angle.
c. The beam is split into its component wavelengths by the grating or prism.
d. By moving the dispersing element or the exit slit, radiation of only a
particular wavelength leaves the monochromator through the exit slit.
8. Sample containers or sample cells
A variety of sample cells available for UV region. The
choice of sample cell is based on
a) the path length, shape, size
b) the transmission characteristics at the desired
wavelength
c) the relative expense
The cell holding the sample should be transparent to the
wavelength region to be recorded.
9. Quartz or fused silica cuvettes are required for
spectroscopy in the UV region.
Silicate glasses can be used for the manufacture of
cuvettes for use between 350 and 2000 nm.
The thickness of the cell is generally 1 cm. cells may
be rectangular in shape or cylindrical with flat ends.
10. Detectors
In order to detect radiation, three types of photosensitive devices
are
a. photovoltaic cells or barrier- layer cell
b. phototubes or photo emissive tubes
c. photomultiplier tubes
11. Photovoltaic cell
Also known as barrier layer or photronic cell.
It consists of a metallic base plate like iron or aluminium which acts as one
electrode.
On its surface, a thin layer of a semiconductor metal like selenium is
deposited. Then the surface of selenium is covered by a very thin layer of
silver or gold which acts as a second collector tube.
When the radiation is incident upon the surface of selenium, electrons are
generated at the selenium- silver surface and the electrons are collected by
the silver. This accumulation at the silver surface creates an electric voltage
difference between the silver surface and the basis of the cell.
12. Phototubes
Also known as photo emissive cells.
A phototube consists of an evacuated glass bulb.
There is light sensitive cathode inside it. The inner
surface of cathode is coated with light sensitive layer
such as potassium oxide and silver oxide.
When radiation is incident upon a cathode,
photoelectrons are emitted.
These are collected by an anode. Then these are
returned via external circuit.
And by this process current is amplified and recorded.
13. The photomultiplier tube
It consists of a photoemissive cathode , several dynode and an anode.
A photon of radiation entering the tube strikes the cathode, causing the
emission of several electrons.
These electrons are accelerated towards the first dynode then onwards
Each original photon has produced 106 - 107 electrons. The resulting current is
amplified and measured.
Photomultipliers are very sensitive to UV and visible radiation. They have fast
response times. Intense light damages photomultipliers; they are limited to
measuring low power radiation.
14.
15. Single Beam Spectrometer
Benefits of Single Beam Design
Less number of optical components results in improved light transmission
and reduced noise
Affords greater sensitivity due to higher light throughput
16. Double Beam Spectrometer
Benefits of Double Beam Design
Correction of absorbance for solvent blank
In single beam design there can be fluctuations in lamp energy between
the ratio recording measurements.
Correction due to fluctuations in stray light, beam intensity variations
and electronic noise are applied in real-time
17.
18. Absorption of EMR by Organic molecules
Absorption of light result in the promotion of an electron from HOMO
to LUMO
i.e movement of valence shell electron ,typically from a filled bonding
MO to unfilled antibonding MO
As conjugation increases HOMO-LUMO gap decreases and the position
of absorption shift to longer wavelength
In saturated alkyl halide energy required decrease with decrease in
electronegativity
The conjugated system needs lower energy for excitation because
energy gap separation is low
19. The Influence of Functional Group in absorption peak
Absorption peaks are also influenced by functional groups.
The functional groups influence the conjugated systems, causing the
absorption peaks to appear at longer wavelengths than the peak wavelength
of benzene, although they do not go beyond 400 nm and enter the visible
region.
The colour of organic compounds, then, is influenced more strongly by the
size of the conjugated system.
20. Chromophore
Functional group not in conjugation with any other group is said to be
chromophore
Generally groups having unsaturated centers or heteroatoms or both
NO2,N=O ,C=O ,C=N ,C=S
Auxochrome
Don’t have selective absorption above 200nm on its own
Along Chromophore shift to a longer wavelength and increase in intensity of
absorption peak
Acidic: −COOH, −OH, −SO3H
Basic: −NH2, −NHR, −NR2
21. The Relationship Between Conjugated Double Bond
Systems and Absorption Peaks
This absorption spectra obtained by dissolving
compounds in ethanol and analysing the resulting
solutions.
The concentrations were adjusted so that the
absorption intensities of the components were
roughly the same.
Peak wavelengths tend to be shifted toward the
long wavelength region as the conjugated system
gets larger
With larger conjugated systems, the absorption
peak wavelengths tend to be shifted toward the
long wavelength region and the absorption peaks
tend to be larger.
23. Solvent Effect
Compound peak could be obscured by the
solvent peak
So a most suitable solvent is one that does
not itself get absorbed in the region under
investigation.
A solvent should be transparent in a
particular region.
A dilute solution of sample is always
prepared for analysis.
Most commonly used solvents are as
follows.
Solvent λ of absorption
Water 191 nm
Ether 215 nm
Methanol 203 nm
Ethanol 204 nm
Chloroform 237 nm
Carbon
tetrachloride
265 nm
Benzene 280 nm
Tetrahydrofuran 220 nm
24.
25. Detection of Impurities
One of the best methods for determination of
impurities in organic molecules.
Additional peaks can be observed due to
impurities in the sample and it can be
compared with that of standard raw material.
By also measuring the absorbance at specific
wavelength, the impurities can be detected
Benzene appears as a common impurity in
cyclohexane. Its presence can be easily
detected by its absorption at 255 nm.
Applications of Absorption Spectroscopy (UV, Visible)
26. Structure elucidation of organic
compounds.
To check the presence or absence of
unsaturation, the presence of hetero
atoms
From the location of peaks and
combination of peaks, it can be
concluded that whether the compound
is saturated or unsaturated, hetero
atoms are present or not etc.
27. Quantitative analysis
Quantitative determination is based on Beer’s law
which is as follows.
A = log I0 / It = log 1/ T = – log T = abc = εbc
Where,
ε is extinction co-efficient,
c is concentration
b is the length of the cell that is used in
UV spectrophotometer
28. Qualitative analysis
Identification is done by comparing the
absorption spectrum with the spectra of
known compounds
UV absorption spectroscopy is generally
used for characterizing aromatic
compounds and aromatic olefins.
29. Chemical kinetics
Kinetics of reaction can also be studied using UV spectroscopy.
The UV radiation is passed through the reaction cell and the
absorbance changes can be observed.
Quantitative analysis of pharmaceutical substances
Many drugs are either in the form of raw material or in the form of
formulation
They can be assayed by making a suitable solution of the drug in a
solvent and measuring the absorbance at specific wavelength.
Diazepam tablet can be analyzed by 0.5% H2SO4 in methanol at
the wavelength 284 nm.
30. As HPLC detector
The presence of an analyte gives a response which can be
assumed to be proportional to the concentration.
For more accurate results, the instrument's response to the
analyte in the unknown should be compared with the response
to a standard; as in the case of calibration curve.
Three types
- Fixed Wavelength
- Variable Wavelength
- Diode array