a brief discussion of AAS, an analytical technique use for heavy metal analysis. Atomic absorption spectroscopy is a quantitative method of analysis of any kind of sample; that is applicable to many metals
AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electro thermal vaporization.
Atomic Absorption Spectroscopy is a very common technique for detecting metals and metalloids in samples.
It is very reliable and simple to use.
It also measures the concentration of metals in the sample.
Atomic Absorption Spectroscopy is an analytical technique that measures the concentration of an element by measuring the amount of light that is absorbed at a characteristic wavelength when it passes through cloud of atoms
As the number of atoms in the light path increases, the amount of light absorbed increases.
Applications: Presence of metals as an impurity or in alloys can be perform.
Level of metals could be detected in tissue samples like Aluminum in blood and Copper in brain tissues.
Due to wear and tear there are different sorts of metals which are given in the lubrication oils which could be determined for the analysis of conditions of machines.
Determination of elements in the agricultural samples.
Water sample analysis (e.g. Ca, Mg, Fe, Si, Al, Ba content).
Food sample analysis.
Analysis of animal feedstuffs (e.g. Mn, Fe, Cu, Cr, Se, Zn).
Analysis of additives in lubricating oils and greases (Ba, Ca, Na, Li, Zn, Mg). analysis of soils.
Clinical sample analysis (blood samples: whole blood, plasma, serum; Ca, Mg, Li, Na, K, Fe).
Analysis of Environmental samples such as- drinking water, ocean water, soil.
Pharmaceutical sample Analysis: Estimation of zinc in insulin preparation, calcium in calcium salt is done by using AAS. Principle: The sample, in solution, is aspirated as a spray into a chamber, where it is mixed with air and fuel.
This mixture passes through baffles, here large drops fall and are drained off. Only fine droplets reach the flame.
Light from the hollow-cathode lamp passes through the sample of ground-state atoms in the flame.
The amount of light absorbed is proportional to the concentration.
The element being determined must be reduced to the elemental state, vaporized, and imposed in the beam of the radiation in the source.
When a ground-state atom absorbs light energy, an excited atom is produced.
The excited atom then returns to the ground state, emitting light of the same energy as it absorbed.
The flame sample thus contains a dynamic population of ground-state and excited atoms, both absorbing and emitting radiant energy. The emitted energy from the flame will go in all directions, and it will be a steady emission.
Because the purpose of the instrument is to measure the amount of light absorbed, the light detector must be able to distinguish between the light beam emitted by the hollow cathode lamp and that emitted by excited atoms in the flame.
Atomic spectroscopy plays a major role as the basis of a wide range of analytical techniques that contribute data on elemental concentrations and isotope ratios .These analytical data provide the raw material on which progress in geochemistry depends.
The main advantages of AAS & AES are that it is relatively inexpensive and easy to use, while still offering high throughput, quantitative analysis of the metal content of solids or liquids. This makes it suitable for use in a wide range of applications.
INSTRUMENTAL METHODS OF ANALYSIS, B.PHARM 7TH SEM. AND FOR BSC,MSC CHEMISTRY. This is Geeta prasad kashyap (Asst. Professor), SVITS, Bilaspur (C.G) 495001
Atomic Absorption spectrometer is an instrument used for quantitative analysis of most of the metals in nano grams. This is highly sensitive technique used for analysis.
Lecture-02.Classifications of Qualitative and Quantitative AnalysisUniversity of Okara
https://www.youtube.com/watch?v=wObwXIt1ZQc&t=123s
Basic Concept of Analytical Chemistry
Meaning: The word analytical comes from the Ancient Greek ana- "up, and lysis "a loosening"). Collectively it means breaking-up" or "an untying.
Definition: The branch of chemistry which deals with the analysis of matter, its identification, and its components. Thus, the process of chemical analysis are of two type;
(1) Qualitative Analysis (2) Quantitative Analysis
Classifications of Analytical Techniques
There are two types of techniques
(1) Classical technique (2) Instrumental techniques
The classical techniques are qualitative as well as quantitative. The qualitative analysis is based on identifying and determining the analyte based on some properties specific to the analyte like boiling point, melting point, optical activities or refractive index, solubilities, and color. E.g., the Boling point of water is 100oC, the melting point of sugar is 186 °C, the refractive index of water is 1.333, test color of K is purple or the color of litmus. paper indicating the acidity or basicity of a compound. When sulphuretted hydrogen (H2S) is passed through a solution containing Arsenic, a yellowish precipitate is formed indicating the presence of arsenic. If the precipitate is brown, is brown, it indicates Tin.
The quantitative analysis is based on the quantity of the analyte. Like determining the volume of the analyte ( volumetric and gasometric analysis) and weight of the analyte (gravimetric analysis.
2) Instrumental methods can be both qualitative and quantitative. The qualitative analysis likewise relies on detecting and determining the analyte based on certain characteristics. Elements (C, H, N, S) of organic compounds using a CHNS analyzer, heavy metals using an atomic absorption spectrophotometer, and alkali and alkaline earth metals (K, Na, Ca, Mg) using a flame photometer. At the molecular level, infrared (IR) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and thin-layer chromatography are used to examine substances. These techniques tell us the nature of a compound. Some of these techniques can also be used for quantitative purposes as well.
Reference Books:
Skoog, D. A., West, P. M., Holler, F. J., Crouch, S. R., Fundamentals of AnalyticalChemistry, 9th ed., Brooks Cole Publishing Company, (2013).
Christian, G. D., Analytical Chemistry. 6th ed., John-Wiley & Sons, New York, (2006).
Harris, D. C., Quantitative Chemical Analysis, 8th ed., W. H. Freeman and Company, New York, USA, (2011).
Bender, G.T. 1987. “Principles of Chemical Instrumentation” W.B. Saunders Co., London.
Reilley, C. 1993. Laboratory Manual of Analytical Chemistry. Allyn& Bacon, London.
Hargis, L.G. 1988. “Analytical Chemistry: Printice Hall Publishers, London.
Pharmaceuticals: In some pharmaceutical manufacturing processes, minute quantities of a catalyst used in the process (usually a metal) are sometimes present in the final product. By using AAS the amount of catalyst present can be determined.
Atomic absorption spectroscopy (AAS) and atomic emission spectroscopy (AES) is a spectro analytical procedure for the quantitative determination of chemical elements by free atoms in the gaseous state.
Atomic absorption spectroscopy is based on absorption of light by free metallic ions.
In analytical chemistry the technique is used for determining the concentration of a particular element (the analyte) in a sample to be analyzed. AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporization
Atomic absorption spectrometry (AAS) is an analytical technique that measures the concentrations of elements.
Atomic absorption is so sensitive that it can measure down to parts per billion of a gram (µg dm–3 ) in a sample.
The technique makes use of the wavelengths of light specifically absorbed by an element. They correspond to the energies needed to promote electrons from one energy level to another, higher, energy level.
Atomic absorption spectrometry has many uses in different areas of chemistry.
Clinical analysis : Analysing metals in biological fluids such as blood and urine.
Environmental analysis: Monitoring our environment – eg finding out the levels of various elements in rivers, seawater, drinking water, air, petrol and drinks such as wine, beer and fruit drinks.
The technique makes use of the atomic absorption spectrum of a sample in order to assess the concentration of specific analytes within it. It requires standards with known analyte content to establish the relation between the measured absorbance and the analyte concentration and relies therefore on the [Beer–Lambert law].
The electrons within an atom exist at various energy levels. When the atom is exposed to its own unique wavelength, it can absorb the energy (photons) and electrons move from a ground state to excited states.
The radiant energy absorbed by the electrons is directly related to the transition that occurs during this process.
Furthermore, since the electronic structure of every element is unique, the radiation absorbed represents a unique property of each individual element and it can be measured.
An atomic absorption spectrometer uses these basic principles and applies them in practical quantitative analysis
A typical atomic absorption spectrometer consists of four main components:
Atomization
Light source,
Atomization system,
Monochromator &
Detection system
Atomization can be carried out either by a flame or furnace.
Heat energy is utilized in atomic absorption spectroscopy to convert metallic elements to atomic dissociated vapor.
The temperature should be controlled very carefully for the conversion of atomic vapor.
At too high temperatures, atoms
A presentation containing the Principle, shematic diagram, omponents of the instrument, working of the instrument, application, advantages and disadvantages of the instrument.
Atomic spectroscopy plays a major role as the basis of a wide range of analytical techniques that contribute data on elemental concentrations and isotope ratios .These analytical data provide the raw material on which progress in geochemistry depends.
The main advantages of AAS & AES are that it is relatively inexpensive and easy to use, while still offering high throughput, quantitative analysis of the metal content of solids or liquids. This makes it suitable for use in a wide range of applications.
INSTRUMENTAL METHODS OF ANALYSIS, B.PHARM 7TH SEM. AND FOR BSC,MSC CHEMISTRY. This is Geeta prasad kashyap (Asst. Professor), SVITS, Bilaspur (C.G) 495001
Atomic Absorption spectrometer is an instrument used for quantitative analysis of most of the metals in nano grams. This is highly sensitive technique used for analysis.
Lecture-02.Classifications of Qualitative and Quantitative AnalysisUniversity of Okara
https://www.youtube.com/watch?v=wObwXIt1ZQc&t=123s
Basic Concept of Analytical Chemistry
Meaning: The word analytical comes from the Ancient Greek ana- "up, and lysis "a loosening"). Collectively it means breaking-up" or "an untying.
Definition: The branch of chemistry which deals with the analysis of matter, its identification, and its components. Thus, the process of chemical analysis are of two type;
(1) Qualitative Analysis (2) Quantitative Analysis
Classifications of Analytical Techniques
There are two types of techniques
(1) Classical technique (2) Instrumental techniques
The classical techniques are qualitative as well as quantitative. The qualitative analysis is based on identifying and determining the analyte based on some properties specific to the analyte like boiling point, melting point, optical activities or refractive index, solubilities, and color. E.g., the Boling point of water is 100oC, the melting point of sugar is 186 °C, the refractive index of water is 1.333, test color of K is purple or the color of litmus. paper indicating the acidity or basicity of a compound. When sulphuretted hydrogen (H2S) is passed through a solution containing Arsenic, a yellowish precipitate is formed indicating the presence of arsenic. If the precipitate is brown, is brown, it indicates Tin.
The quantitative analysis is based on the quantity of the analyte. Like determining the volume of the analyte ( volumetric and gasometric analysis) and weight of the analyte (gravimetric analysis.
2) Instrumental methods can be both qualitative and quantitative. The qualitative analysis likewise relies on detecting and determining the analyte based on certain characteristics. Elements (C, H, N, S) of organic compounds using a CHNS analyzer, heavy metals using an atomic absorption spectrophotometer, and alkali and alkaline earth metals (K, Na, Ca, Mg) using a flame photometer. At the molecular level, infrared (IR) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and thin-layer chromatography are used to examine substances. These techniques tell us the nature of a compound. Some of these techniques can also be used for quantitative purposes as well.
Reference Books:
Skoog, D. A., West, P. M., Holler, F. J., Crouch, S. R., Fundamentals of AnalyticalChemistry, 9th ed., Brooks Cole Publishing Company, (2013).
Christian, G. D., Analytical Chemistry. 6th ed., John-Wiley & Sons, New York, (2006).
Harris, D. C., Quantitative Chemical Analysis, 8th ed., W. H. Freeman and Company, New York, USA, (2011).
Bender, G.T. 1987. “Principles of Chemical Instrumentation” W.B. Saunders Co., London.
Reilley, C. 1993. Laboratory Manual of Analytical Chemistry. Allyn& Bacon, London.
Hargis, L.G. 1988. “Analytical Chemistry: Printice Hall Publishers, London.
Pharmaceuticals: In some pharmaceutical manufacturing processes, minute quantities of a catalyst used in the process (usually a metal) are sometimes present in the final product. By using AAS the amount of catalyst present can be determined.
Atomic absorption spectroscopy (AAS) and atomic emission spectroscopy (AES) is a spectro analytical procedure for the quantitative determination of chemical elements by free atoms in the gaseous state.
Atomic absorption spectroscopy is based on absorption of light by free metallic ions.
In analytical chemistry the technique is used for determining the concentration of a particular element (the analyte) in a sample to be analyzed. AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporization
Atomic absorption spectrometry (AAS) is an analytical technique that measures the concentrations of elements.
Atomic absorption is so sensitive that it can measure down to parts per billion of a gram (µg dm–3 ) in a sample.
The technique makes use of the wavelengths of light specifically absorbed by an element. They correspond to the energies needed to promote electrons from one energy level to another, higher, energy level.
Atomic absorption spectrometry has many uses in different areas of chemistry.
Clinical analysis : Analysing metals in biological fluids such as blood and urine.
Environmental analysis: Monitoring our environment – eg finding out the levels of various elements in rivers, seawater, drinking water, air, petrol and drinks such as wine, beer and fruit drinks.
The technique makes use of the atomic absorption spectrum of a sample in order to assess the concentration of specific analytes within it. It requires standards with known analyte content to establish the relation between the measured absorbance and the analyte concentration and relies therefore on the [Beer–Lambert law].
The electrons within an atom exist at various energy levels. When the atom is exposed to its own unique wavelength, it can absorb the energy (photons) and electrons move from a ground state to excited states.
The radiant energy absorbed by the electrons is directly related to the transition that occurs during this process.
Furthermore, since the electronic structure of every element is unique, the radiation absorbed represents a unique property of each individual element and it can be measured.
An atomic absorption spectrometer uses these basic principles and applies them in practical quantitative analysis
A typical atomic absorption spectrometer consists of four main components:
Atomization
Light source,
Atomization system,
Monochromator &
Detection system
Atomization can be carried out either by a flame or furnace.
Heat energy is utilized in atomic absorption spectroscopy to convert metallic elements to atomic dissociated vapor.
The temperature should be controlled very carefully for the conversion of atomic vapor.
At too high temperatures, atoms
A presentation containing the Principle, shematic diagram, omponents of the instrument, working of the instrument, application, advantages and disadvantages of the instrument.
It relate with the spectrophotometry. The components and the uses of each of them are detailed. The ultimate goal of using this spectrometry and the uses of them also explained well.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
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I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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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
3. Atomic absorption spectroscopy is a quantitative method of analysis of any kind
of sample; that is applicable to many metals
AAS can be used to determine over 70 different elements in solution, or
directly in solid samples via electro thermal vaporization.
Atomic Absorption Spectroscopy is a very common technique for detecting
metals and metalloids in samples.
It is very reliable and simple to use.
It also measures the concentration of metals in the sample.
Atomic Absorption Spectroscopy is an analytical technique that measures the
concentration of an element by measuring the amount of light that is absorbed at
a characteristic wavelength when it passes through cloud of atoms
As the number of atoms in the light path increases, the amount of light absorbed
increases.
Optical Atomic Spectroscopy/ Optical Spectrometry
Absorption
Emission
INTRODUCTION
3
4. ATOMIC EMISSION SPECTROSCOPY
Examines the wavelengths of photons
emitted by atoms or molecules during
their transition from an excited state to a
lower energy state.
Each element emits a characteristic set
of discrete wavelengths.
By observing these wavelengths the
elemental composition of the sample can
be determined.
ATOMIC ABSORPTION SPECTROSCPY
Measures the loss of electromagnetic
energy after it illuminates the sample
under study.
The energy in certain amount is
absorbed during transition to the higher
level.
The amount of energy absorbed gives
estimate of the concentration of the
analyte in the sample.
COMPARISON
4
6. The sample, in solution, is aspirated as a spray into a chamber, where it is mixed
with air and fuel.
This mixture passes through baffles, here large drops fall and are drained off. Only
fine droplets reach the flame.
Light from the hollow-cathode lamp passes through the sample of ground-state
atoms in the flame.
The amount of light absorbed is proportional to the concentration.
The element being determined must be reduced to the elemental state, vaporized, and
imposed in the beam of the radiation in the source.
When a ground-state atom absorbs light energy, an excited atom is produced.
The excited atom then returns to the ground state, emitting light of the same energy
as it absorbed.
The flame sample thus contains a dynamic population of ground-state and excited
atoms, both absorbing and emitting radiant energy. The emitted energy from the
flame will go in all directions, and it will be a steady emission.
Because the purpose of the instrument is to measure the amount of light absorbed,
the light detector must be able to distinguish between the light beam emitted by the
hollow cathode lamp and that emitted by excited atoms in the flame.
PRINCIPLE
6
8. Hollow Cathode Lamp (HCL)
the most common radiation source in AAS.
It contains a tungsten anode and a hollow
cylindrical cathode made of the element to be
determined.
These are sealed in a glass tube filled with an
inert gas (neon or argon).
Each element has its own unique lamp which
must be used for that analysis.
The invention of hollow cathode lamp by
Walsh in 1955 made practical applications of
AAS possible
1. LIGHT SOURCE
Electrode-less Discharge Lamps (EDL)
designed to be physically interchangeable with Lumina Hollow Cathode Lamps.
The benefits of electrode- less discharge lamps are realized especially when
analyzing volatile elements like As, Sb, Bi, Cd, Hg, Rb, Sn, Te, etc. Sputtering of
such metal atoms and their adsorption on cathode lamp side walls and windows
begins to affect the useful life of the lamps.
Their power supplies are built into all PinAAcle series of atomic absorption
spectrometers. PerkinElmer System 2 EDLs consist of the element, or a salt of the
element, sealed in a quartz bulb containing an inert gas atmosphere. 8
9. 2. NEBULIZER
suck up liquid samples at controlled
rate.
create a fine aerosol spray for
introduction into flame.
Mix the aerosol and fuel and oxidant
thoroughly for introduction into
flame.
9
10. Atomization is separation of particles into individual molecules and breaking
molecules into atoms.
This is done by exposing the analyte to high temperatures in a flame or graphite
furnace.
Sample Atomization Technique
Flame Atomization
Electro thermal Atomization
Hydride Atomization
Cold- Vapour Atomization
3. ATOMIZATION
10
11. Nebulization is process by which sample liquid converts into a fine mist & aerosols.
Desolvation is a thermodynamically driven, self-assembly process for polymeric
materials to prepare nanoparticles.
Volatilization is the process of converting a chemical substance from a liquid or solid
state to a gaseous or vapor state.
Dissociation is process in which molecules (or ionic compounds such as salts, or
complexes) separate or split into other things such as atoms, ions, or radicals, usually
in a reversible manner.
Flame Atomization
To create flame, we need to
mix an oxidant gas and a fuel
gas.
in most of the cases air-
acetylene flame or nitrous
oxide- acetylene flame is used.
liquid or dissolved samples are
typically used with flame
atomizer.
11
12. This is a very important part in an AA spectrometer. It is used to separate out all of
the thousands of lines.
A Monochromator is used to select the specific wavelength of light which is
absorbed by the sample, and to exclude other wavelengths.
The selection of the specific light allows the determination of the selected element
in the presence of others.
4. MONOCHROMATOR
12
5. DETECTOR
The light selected by the Monochromator is directed onto a detector that is
typically a photomultiplier tube, whose function is to convert the light signal into
an electrical signal proportional to the light intensity.
The processing of electrical signal is fulfilled by a signal amplifier.
The signal could be displayed for readout, or further fed into a data station for
printout by the requested format.
13. A calibration curve is used to determine the unknown concentration of an
element in a solution.
The instrument is calibrated using several solutions of known concentrations.
The absorbance of each known solution is measured and then a calibration
curve of concentration vs absorbance is plotted.
The sample solution is fed into the instrument, and the absorbance of the
element in this solution is measured.
The unknown concentration of the element is then calculated from the
calibration curve.
Calibration Curve
13
14. Interference is a phenomenon that leads to change in intensity of analyte signal in
spectroscopy.
Interferences in AAS fall into two basic categories:
Non-Spectral Interferences affect the formation of analyte items.
Spectral Interferences
high light absorption due to presence of absorbing species
Matrix Interference: When a sample is more viscous or has different surface
tension than the standard it result in difference in sample uptake rate due to
changes in nebulization efficiency.
Chemical interference: If a sample contains a species which forms a thermally
stable compound with analyte that is not completely decomposed by the flame
energy then chemical interferences exist.
Ionization Interference: It is more common in hot flames. The dissociation
process doesn't stop at formation of ground state atoms.
Spectral Interferences: Spectral interferences are caused by presence of another
atomic absorption line or a molecular absorbance band close to the spectral line
of element of interest.
Interferences
14
16. Presence of metals as an impurity or in alloys can be perform.
Level of metals could be detected in tissue samples like Aluminum in blood and
Copper in brain tissues.
Due to wear and tear there are different sorts of metals which are given in the
lubrication oils which could be determined for the analysis of conditions of
machines.
Determination of elements in the agricultural samples.
Water sample analysis (e.g. Ca, Mg, Fe, Si, Al, Ba content).
Food sample analysis.
Analysis of animal feedstuffs (e.g. Mn, Fe, Cu, Cr, Se, Zn).
Analysis of additives in lubricating oils and greases (Ba, Ca, Na, Li, Zn, Mg).
analysis of soils.
Clinical sample analysis (blood samples: whole blood, plasma, serum; Ca, Mg,
Li, Na, K, Fe).
Analysis of Environmental samples such as- drinking water, ocean water, soil.
Pharmaceutical sample Analysis: Estimation of zinc in insulin preparation,
calcium in calcium salt is done by using AAS.
APPLICATIONS
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