...Photon correlation spectroscopy Photon Correlation Spectroscopy (PCS) is a technique that is used to determine the size distribution of small particles in suspension or polymers in liquid solution. It’s also known as dynamic light scattering. It can also be used to probe the behavior of complex fluids such as concentrated polymer solutions. Principle When light hits small particles, the light scatters in all directions as long as the particles are small compared to the wavelength. According to the Stokes Einstein’s theory, particle Brownian motion depending on the viscosity of the suspending fluid, temperature of the fluid, diffusion coefficients of polymeric samples, molecular weights of polymers and the size of particles suspending in the fluid. Thus, the graph of scattered light can be used to determine the diffusion of particles which correlates the particle sizes. Application PCS is used to characterize size of various particles including proteins, polymers, micelles, carbohydrates, and nanoparticles. If the system is mono-disperse, the mean effective diameter of the particles can be determined. This measurement depends on the size of the particle core, the size of surface structures, particle concentration, and the type of ions in the medium. Since PCS essentially measures fluctuations in scattered light intensity due to diffusing particles, the diffusion coefficient of the particles can be determined. PCS software of commercial instruments typically displays...
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...IR SPECTROSCOPY WITH INSTRUMENTATION BY MUHAMMAD ABDUL WAHAB ROL#428 Msc 2 SUBMITTED TO Dr.S.Mustansar Abbas IR SPECTROSCOPY It is the method or process to getting information about atoms and molecule by using electromagnetic radiation. OR The method of “seeing the unseenable”atoms and molecule. The field of spectroscopy related with internal structure of atom or molecule.There are different types of radiation but we use here IR RADIATION to analyte vibration change in electrons by IR Spectrum. INFRARED SPECTROSCOPY • IR Spectroscopy can be define as • The Study of concentration or specific obserption of infrared radiation which cause vibrational transition in the molecule. • IR light have longer wavelength and lower...
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...|CM2101 (Principles of Spectroscopy) | |Experiment 1: Rovibrational Spectrum of Hydrogen Chloride | AIM To measure the infra-red (IR) spectrum of gaseous HCl using Fourier Transform Infra-Red (FTIR) spectrometer, and analyse the rotational fine structures. ABSTRACT The experiment aims to identify various parameters of gaseous HCl related to quantum mechanics by using high-resolution IR spectrum and graphical method of analysis. The values that are being investigated specifically are νe (equilibrium vibrational frequency), νeχe (product of equilibrium vibrational frequency and anharmonicity constant), k (force constant), B0 (rotational constant at n = 0), B1 (rotational constant at n = 1), Be (rotational constant at equilibrium internuclear distance), α (Coriolis constant) and re (equilibrium internuclear distance). The spectrum obtained shows strong fundamental absorption band approximately between 3100 and 2600 cm-1, with the origin of the band approximately at 2880 cm-1. It is also characterised by the presence of P and R branches which spreads out from the origin, with the former being present at a lower wavenumber region than the latter. In addition, double peaks are observed due to the presence of two isotopes of chlorine: 35Cl and 37Cl. INTRODUCTION One of the areas being...
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...Abstract: Fluorescence has many practical applications such as mineralogy and chemical sensors. In this experiment, the fluorescence spectrum of an organic dye, Fluorescein was obtained and compared with its absorption spectrum. It was found that Fluorescein has a maximum absorption wavelength at (486±2) nm and maximum fluorescence emission at (517±2) nm. The cause in the shift of the wavelength between the absorbed and the emitted photons, known as the stroke’s shift, was caused by the collisional and vibrational non-radioactive decay in which some of the energy from the absorbed photon is converted into heat to the surrounding molecules. Hence the emitted photons have less energy and longer wavelength as: E=hv (1) These processes occur before the fluorescence because they have a much shorter lifetime (10-12 s) compared to the lifetime of the fluorescence (10-8 s) and thus competes effectively with fluorescence. Introduction: The aim of this experiment is to obtain the absorption and fluorescence spectrum in the organic dye molecule, Fluorescein. First, the spectrum of a xenon lamp was obtained using a monochromator combined with a photomultiplier tube detector. Then a fluorescence dye was inserted between the xenon lamp and the detector in order to obtain the absorption spectrum of the fluorescein dye. The equipment set up was then altered to investigate the fluorescence spectrum of the dye. The absorption spectrum and the fluorescence spectrum...
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...determine if they are “okay” to drive. The purpose of this project is to study, design ,build, and test a fixed frequency photospectrometer that will test the blood alcohol content of a person non-invasively. BACKGROUND Over the past decades a new method for measurement has been rapidly envancing. This method is a photonic technique that envolves electromagnetic radiation. Electromagnetic radiation has several forms including visible and infrared light radiation. Visible light radiation ranges from 370nm to 760nm, while infrared ranges from 760nm to approximately 1OE-4nm. Mark A. Arnold at the university of Iowa in Iowa City and Gary W.Small at Ohio University in Athens have been focusing on near-infrared (800nm to 1000nm) absorption spectroscopy as a solution to non-invasive glucose monitoring. Problems that have occurred revolve around the broad absorption signals of near-infrared radiation making it more difficult to identi@ a specific analyte. Arnold estimates that a working device is still five years away. A Biophotonic success is the Pulse Oximeter. It is a ten year old deviqe used to monitor patient’s conditions under anesthesia. It uses two LEDs that emit light at a wavelength of 660nm and 940nm respectively. Oxygenated blood absorbs strongly at 660nm. As cumulative blood oxygenation changes, the ratio of the light transmitted by the two frequencies changes. The unit detects the peaks and valleys, allowing it to separate the arterial blood 0-7803-5078-2/98/$10.00 0 1998...
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...The purpose of this lab was to get used to using lab machinery such as the spectrometer. Spectroscopy is the interaction of matter and electromagnetic radiation. Most of our lab was based on the idea that matter would absorb and then reflect the colors we wanted to see based on the dyes we used. We also tested how strong the dyes were by testing them on filter paper and seeing how far they would travel up the paper. During dry lab we put all the classes’ data together to get accurate absorbance averages for both Musk-ade red and blue. For red the average was 0.000100615, and blue was 0.001701276. Then we found a class standard deviation value 0.003750326. We also graphed the absorbance levels along with their concentrations of both red and blue dyes....
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...This page takes a brief look at the Beer-Lambert Law and explains the use of the terms absorbance and molar absorptivity relating to UV-visible absorption spectrometry. AbsorbanceMeasuring the absorbance of a solutionIf you have read the page about how an absorption spectrometer works, you will know that it passes a whole series of wavelengths of light through a solution of a substance (the sample cell) and also through an identical container (the reference cell) which only has solvent in it. | | Note: It isn't essential to read about how the spectrometerworks, but you could follow this link if you are interested or if it is on your syllabus. Everything you need from that page to understand the present topic is repeated below. | For each wavelength of light passing through the spectrometer, the intensity of the light passing through the reference cell is measured. This is usually referred to as Io - that's I for Intensity.The intensity of the light passing through the sample cell is also measured for that wavelength - given the symbol, I.If I is less than Io, then obviously the sample has absorbed some of the light. A simple bit of maths is then done in the computer to convert this into something called the absorbance of the sample - given the symbol, A.For reasons to do with the form of the Beer-Lambert Law (below), the relationship between A (the absorbance) and the two intensities is given by:On most of the diagrams you will come across, the absorbance...
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...Step 1: Calculate the degree of unsaturation. The degree of unsaturation indicates number of double bonds present in the compound. Step 2: See the IR spectrum, specially the region of wavenumbers greater than 1500 cm-1 . Look for likely functional groups keeping in mind, the degree of unsaturation and molecular formula. e.g, if there is one double bond and an oxygen, it could be a carbonyl; if there is no double bond and an oxygen, it will be either an ether or an alcohol; if there are 4 double bonds, there might be an aromatic ring. Step 3: See the PMRand 13C NMR spectrum.Check that the functional groups infered by IR and NMR are consistent or not. Step 4: Draw possible structures consistent with the unsaturation, IR, and NMR data. Check the total number of carbons, oxygens, hydrogens, etc. consistent with the molecular formula.Verify the molecular weight and base peak as well as fragmentation pattern from mass spectrum. Degree of unsaturation: The degree of unsaturation can be calculated from the molecular formula of compound containing carbon, hydrogen, oxygen, nitrogen, sulfur, or the halogens. A calculation of the degree of unsaturation tells us how many rings and double bonds are in the molecule; thus, we have an idea about presence of a carbonyl or a carbon-carbon double bond or a ring or an aromatic ring in the compound. Rules: • Rule 1: Replace halogen in the molecular formula by ‘CH3’ • Rule 2: Omit oxygens and sulphurs. • Rule 3: Replace nitrogen by ‘CH’. By using...
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...Application of Spectroscopy Astronomical Spectroscopy Energy from celestial objects is used to analyze their chemical composition, density, pressure, temperature, magnetic fields, velocity, and other characteristics. There are many energy types (spectroscopies) that may be used in astronomical spectroscopy. Atomic Absorption Spectroscopy Energy absorbed by the sample is used to assess its characteristics. Sometimes absorbed energy causes light to be released from the sample, which may be measured by a technique such as fluorescence spectroscopy. Attenuated Total Reflectance Spectroscopy This is the study of substances in thin films or on surfaces. The sample is penetrated by an energy beam one or more times and the reflected energy is analyzed. Attenuated total reflectance spectroscopy and the related technique called frustrated multiple internal reflection spectroscopy are used to analyse coatings and opaque liquids. Electron Paramagnetic Spectroscopy This is a microwave technique based on splitting electronic energy fields in a magnetic field. It is used to determine structures of samples containing unpaired electrons. Electron Spectroscopy There are several types of electron spectroscopy, all associated with measuring changes in electronic energy levels. Fourier Transform Spectrosopy This is a family of spectroscopic techniques in which the sample is irradiated by all relevant wavelengths simultaneously for a short period of time. The absorption spectrum...
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...Spectroscopy CONTENTS Introduction Physical Quantities measured What Is Spectroscopy Nature of light The Electromagnetic Spectrum General Types of Spectra Continuous Spectra Emission spectra Absorption Spectra Types of Spectroscopy How Spectrometer work? Types of Spectroscopy Examples of Spectroscopy in Astronomy Probing the Formation of Stars in Colliding Galaxies in the universe. Uncovering the mystery of quasar Spectroscopy in Astronomy camp Stars like our own Sun Bibliography 1. Introduction Spectroscopy Spectroscopy is the study of matter and its properties by investigating light, sound, or particles that are emitted, absorbed or scattered by the matter under investigation. Spectroscopy may also be defined as the study of the interaction between light and matter. Historically, spectroscopy referred to a branch of science in which visible light was used for theoretical studies on the structure of matter and for qualitative and quantitative analyses. Recently, however, the definition has broadened as new techniques have been developed that utilize not only visible light, but many other forms of electromagnetic and non-electromagnetic radiation: microwaves, radiowaves, x-rays, electrons, phonons (sound waves) and others. Impedance spectroscopy is a study of frequency response in alternating current. Spectroscopy is often used in physical and analytical chemistry for the identification of substances through the spectrum emitted from them or absorbed...
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...Practical 2 – UV-Visible Spectroscopy Iron in dietary supplements Introduction UV-Visible spectroscopy is an analytical technique involving measurement of the UV-visible light absorbed by substances, and is therefore commonly used for determining the concentration of a substance in a sample. Many substances absorb energies of particular wavelengths, while transmitting energy of other wavelengths. A UV-visible spectrum is produced when photons that are present in this particular region of the electromagnetic spectrum gain energy; causing electrons to jump from to higher energy levels than the ones they previously existed in. Not all substances have the same energy levels, since they vary from substance to substance. This in turn means that the energy and wavelength of the light required to move electrons from their energy levels also varies between substances. Hence it is possible to use the specific spectrum produced by each substance to identify what it is. A substance that absorbs light appears coloured, however the observable colour is the complement of the colour(s) absorbed, i.e. the colour not absorbed, since it is what remains to reach our eyes. UV-Visible spectroscopy can be used to obtain qualitative data, such as through identifying compounds using spectra compounds, or quantitative analysis. However, it is generally used for quantitative analysis, in order to determine the concentration of substance in a sample. In this procedure, the spectrum of the pure...
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...BIO 566 INTRODUCTION TO BIOPHYSICS QUIZ 2 MAC-JULY 2012 Question 1 Write an essay on spectroscopy which includes : (15 marks) Basic principles, nature of electromagnetic radiation, types of spectra-(absorbance, emission and fluorescene) types of spectroscopy – (principle, instrumentation and applications of atomic absortion spectroscopy, UV Visible Spectroscopy, Nuclear Magnetic Resonance Spectroscopy and Electron Spin Resonance Spectroscopy) Spectroscopy is the study of the absorption and emission of light and other radiation by matter, as related to the dependence of these processes on the wavelength of the radiation. More recently, the definition has been expanded to include the study of the interactions between particles such as electrons, protons, and ions, as well as their interaction with other particles as a function of their collision energy. Spectroscopic analysis has been crucial in the development of the most fundamental theories in physics, including quantum mechanics, the special and general theories of relativity, and quantum electrodynamics. Spectroscopy, as applied to high-energy collisions, has been a key tool in developing scientific understanding not only of the electromagnetic force but also of the strong and weak nuclear forces. The basic principle shared by all spectroscopic techniques is to shine a beam of electromagnetic radiation onto a sample, and observe how it responds to such a stimulus. The...
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...lab done this semester the dilution I did was the problem. Will send this one as a reference that I understand the concept and calculation of the lab and will send another lab explaining the errors. AA1 - Varian Spectra AA 200 Experiments INTRODUCTION Concept: Atomic absorption spectroscopy (AAS) is a spectra analytical procedure for the quantitative determination of chemical elements employing the absorption of optical radiation (light) by free atoms. It is capable of measuring the concentrations of a wide variety of element in sample. In AAS method measures the light absorbed by the very large proportion of atoms in the ground state. It is a widely used technique due to its simplicity, effectiveness, and relatively low cost. Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids, the analyses atoms or ions must be vaporized in a flame or graphite furnace. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels. The analyse concentration is determined from the amount of absorption. Applying the Beer-Lambert law directly in AA spectroscopy is difficult due to variations in the atomization efficiency from the sample matrix, and non uniformity of concentration and path length of analyses atoms (in graphite furnace AA). Concentration measurements are usually determined from a working curve after calibrating the instrument with...
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...Maria Vasilenko 223901 Feasibility of using biosensors for heavy metal detection in complex matrices such as bio-slurries. Master of Science Thesis Examiners: Professor Matti Karp Professor Raghida Lepistö Examiner and topic approved in The Science and Bioengineering Department Council meeting on 7.11.2012 Abstract TAMPERE UNIVERSITY OF TECHNOLOGY Master‟s Degree Programme in Science and Bioengineering Vasilenko Maria: Feasibility of using biosensors for heavy metal detection in complex matrices such as bio-slurries. Seminar paper, 97 pages November 2012 Major: Biotechnology Examiners: Matti Karp, Raghida Lepisto Keywords: environmental pollution, heavy metals, biosensors, slurries The quality of bioslurries that are used in industrial production and agriculture need to be watched very closely to avoid spreading of contaminants on area and poisoning of humans and animals. Because heavy metals are very stable and toxic in many chemical compositions, their amount should be estimated very thoroughly. A new approach that involved biosensors was tested in this study. Because the slurries are complex non-unified matrices which composed of two phases – solid and liquid, the cell behavior can varies a lot from the one that explained in water and so the estimation of ion concentration can be not reliable. It was shown that the cell actually behave different in the slurries. Normally the dissolved compounds suppress the biosensor activity and, in the same time, the ions in the...
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...UV-Visible Spectrophotometer Calibration S.ZALI M.Sc. Dept. of Analytical chemistry Razi vaccine serum research institute S.Zali@rvsri.ir 2008 The primary objective of GLP is to ensure the generation of high quality data. Essential to this is the ability to produce estimates for the measurement uncertainty associated with calibrations. V The spectrophotometer has become the workhorse for high throughput routine testing for a wide variety of analysts in chemical and biochemical analysis laboratories. It is important for accuracy and reproducibility in measurement that this instrument is correctly set up and calibrated. Increasing Wavelength 50,000 Gamma X-ray 12,820 UV 200 4000 NIR 380 780 IR 2500 400 cm-1 FIR Micro Radio 25 000 nm Increasing Energy K-shell electrons Outer-shell electrons Molecular vibrations Molecular Rotation Conventional Spectrophotometer: The factors that must be calibrated: Control of wavelengths Control of absorbance Limit of stray light Resolution Spectral slit width Cell Control of wavelengths: Wavelength standards: The ideal wavelength standard would have very narrow and very well defined peaks. Control of wavelengths: •Solution of holmium(III) in perchloric acid: 240– 640 nm. •Holmium oxide filters: 280–640 nm. •Didymium filters: 400–750 nm. •Using of spectral lines in low-pressure discharge lamps: 656.1 nm produced by...
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