Mass Spectroscopy and Raman Spectroscopy - Essay Example

Mass spectroscopy and Raman spectroscopy Spectroscopy, or spectrometry, is the science that studies the capa of certain materials to either absorb or emit power in a specific section in the electromagnetic spectrum (Flowers and Silver, 2004; p.953). The data or information derived from using any spectroscopic technique is called a spectrum. A spectrum is a portion of the energy level which was detected against the wavelength of the energy. A spectrum is used to derive information on atomic and molecular energy levels, interactions of molecules, molecular geometries, and chemical bonds. In qualitative analysis, the resulting spectra are used to classify the components of a sample, while in quantitative analysis, spectra is used to measure the amount of material in a sample. (Ahuja and Alsante, 2003; p.16) Organic chemists define this science as the study of the "quantised interaction of electromagnetic radiations with matter" (Yadav, 2005; p.1). According to Yadav (2005), these electromagnetic emissions are created by the fluctuations of electric charges and the magnetic field existing in the atom. He further said that the various forms of electromagnetic radiation include ultraviolet, infrared, x-rays, microwaves, radio waves, and so on (Yadav, 2005; p.1). There are four methods or measurement techniques used in spectroscopy. These are: mass spectroscopy, or MS; ultraviolet spectroscopy, or UV; infrared spectroscopy, or IR; and nuclear magnetic resonance spectroscopy, or NMR. The common types of spectroscopy include: astronomical spectroscopy, atomic absorption spectroscopy, attenuated total reflectance spectroscopy, electron spectroscopy, Fourier-transform spectroscopy, gamma-ray spectroscopy, and laser spectroscopy. (Flowers and Silver, 2004; p.953) A new technique, Raman spectroscopy, is now considered the fifth spectroscopic measurement technique (Smith and Dent, 2005; p.1) The three main types of spectroscopy/spectrometry include: absorption spectroscopy, emission spectroscopy, and scattering spectroscopy. Absorption spectroscopy uses electromagnetic spectra which are absorbed by a particular sample substance. In emission spectroscopy, the electromagnetic spectrum is radiated by the sample substance. In scattering spectroscopy determines the sample's physical properties through the amount of light that the substance scatters at specific wavelengths, incident and polarization angles. The difference between scattering spectroscopy and emission spectroscopy lies in the fact that the scattering process is faster than the absorption or emission process (Flowers and Silver, 2004; p.953; Ahuja and Alsante, 2003; p.16). Mass spectroscopy as a technique offers outstanding structural information of different substances. It can also be a useful tool in separating molecules with little differences in their molecular weight. However, if mass spectroscopy is used as a quantitative measurement technique, its uses can be limited (Ahuja and Alsante, 2003; p.16). In ultraviolet spectroscopy, a sample substance is continuously irradiated with ultraviolet radiation of differing wavelengths. The power or energy which is related with the section of the electromagnetic spectrum matches the difference in power levels among various molecular orbitals. Ultraviolet radiation is created when a sample substance is exposed to a wavelength that equals the variation in energy between an occupied molecular orbital and an unoccupied molecular orbital. (Flowers and Silver, 2004; p.953) Ultraviolet spectroscopy, at a single wavelength, provides little selectivity of analysis (Ahuja and Alsante, 2003; p.16). Infrared spectroscopy, according to Stuart (2004), is definitely one of the most significant analytical measurement techniques that are available to scientists nowadays. (Stuart, 2004; p.1) This method offers precise information for some functional substance groups that present selectivity and allow quantification. (Ahuja and Alsante, 2003; p.16) This technique is based on the atoms' vibrations within a molecule; where an infrared spectrum is acquired by passing infrared waves through a particular material sample and establishing which portion of the radiation was absorbed. (Stuart, 2004; p.2) A great advantage of infrared spectroscopy is that it can study any sample at any given state. This technique can check a variety of liquids and solutions, pastes, even powders, films, fibres, and solid surfaces (Stuart, 2004; p.1). Nuclear magnetic resonance spectroscopy offers the structural information of a molecule in detail. It is also an important technique in classifying impurities found in material samples. Like mass spectroscopy, nuclear magnetic resonance spectroscopy has limited capacity when used as a quantitative tool (Ahuja and Alsante, 2003; p.16). Recent advances in the field of medicine use this technique in combination with other methods, such as computational modelling, to better understand the growth pattern of cancer cells. Laboratory experiments using this technique have confirmed earlier simulation results of protein structures. With the help of this technique, a molecule's physical, chemical, electronic, and structural information becomes easily available for further studies (Rennie, December 2005; pp.17-18). The fifth technique, Raman spectroscopy, has its basis on the amount of scattered electromagnetic waves which come from irradiation process of matter. This method measures the energy difference between scattered rays and incident rays. Raman spectroscopy has been considered to complement infrared spectroscopy because the two techniques offer a complete vibrational profile of any given sample material. The Raman technique is not as widely used as infrared spectroscopy because of the significant high costs of instrumentation and its complexity. In spite of this observation, Raman spectroscopy has been proven to be an effective tool in the field of chromatography and detection of the presence of polymorphs (Ahuja and Alsante, 2003; p.16) Mass spectroscopy, according to Mellon et. al. is a spectroscopic technique that deals with the systems which cause the "formation of gaseous ions, with or without fragmentation, which are then characterised by their mass to charge ratios and relative abundances". (Mellon et. al., 2000; p.3) Unlike the other techniques used in spectroscopy, mass spectroscopy is not an absorption spectroscopy. It is used to establish the molecular weight of a particular substance. (Flowers and Silver, 2004; p. 953) In mass spectroscopy, the spectra of compounds are adequately precise so they can be identified with a high level of confidence and certainty. When the sample material to be analysed (analyte) is part of a mixture, the spectrum will have all the ions of all the present compounds. If the analyte is a minor component in the particular mixture, identification will not be as easy. However, the technique of mass spectroscopy combined with chromatography has made differentiation possible. This high level of specificity makes mass spectroscopy allows better identification of compounds (Ardrey, 2003; p. 3). The history of mass spectroscopy may be traced to the time when Sir J. J. Thomson of the Cavendish Laboratory of the University of Cambridge, discovered the electron in 1897. During the first decade of the 20th century, Thomson constructed the first mass spectrometer, also called parabola spectrograph, to determine the mass-to-charge ratios of ions. He was later awarded the 1906 Nobel Prize in Physics to recognize his theoretical and experimental studies on the conduction of electricity by gases (Nier, 1998; pp 552-56). Later on, Francis W. Aston of the University of Cambridge designed a new mass spectrometer wherein ions were dispersed by mass and directed by velocity. Aston's creation helped improve the resolving power of mass spectrometry through magnitude over resolution. Like his mentor, Aston got the 1922 Nobel Prize in Chemistry for the studies he conducted on isotopes wherein he used the mass spectrometer he developed. (Nier, 1998; pp 552-56) In 1920, University of Chicago physics Professor A. J. Dempster developed an instrument which deflects magnetic fields with direction focusing. This pattern was copied for commercial purposes and is still in use as of present times (Nier, 1998; pp 552-56). In the 1950s, the method of mass spectroscopy is further enhanced when new instruments were developed and new applications and uses for this technique were discovered. An example is the discovery of low molecular mass of food flavour composites. (Mellon et. al., 2000; p. 2) Table 1 below summarizes the historical developments in the field of mass spectroscopy from the creation of the first mass spectrometer to the application of mass spectroscopy to viral analysis. Table 1. Historical developments in mass spectroscopy. Investigator (s) Year Contribution Thomson 1899-1911 First mass spectrometer was introduced Dempster 1918 Mass spectroscopy was used in electron ionization and magnetic focusing Aston 1919 Mass spectroscopy was used in measuring atomic weights Stephens 1946 Introduction of time-of-flight mass analysis Hipple, Sommer, and Thomas 1949 Mass spectroscopy is used in Ion cyclotron resonance Johnson and Nier 1953 Double-focusing instruments were introduced Paul and Steinwedel 1953 Quadrupole analyzers were introduced Beynon 1956 High-resolution mass spectroscopy is in use Biemann, Cone, Webster, and Arsenault 1966 Mass spectroscopy is used in peptide sequencing Munson and Field 1966 Mass spectroscopy is used in chemical ionization Dole 1968 Mass spectroscopy is used in Electrospray ionization Beckey 1969 Field desorption mass spectroscopy of organic molecules is done MacFarlane and Torgerson 1974 Plasma desorption mass spectroscopy is introduced Comisarow and Marshall 1974 FT-ICR mass spectroscopy is in use Yost and Enke 1978 Triple quadrupole mass spectroscopy is in use Barber 1981 Fast atom bombardment (FAB) was introduced Tanaka, Karas, and Hillenkamp 1983 Matrix-assisted laser desorption/ionization was introduced Fenn 1984 ESI on biomolecules Chowdhury, Katta, and Chait 1990 Protein conformational changes with ESI MS Mann and Wilm 1991 MicroESI Ganem, Li, and Henion Chait and Katta 1991 Noncovalent complexes with ESI MS Pieles, Zurcher, Schr, and Moser 1993 Oligonucleotide ladder sequencing was introduced Henzel, Billeci, Stults, Wong, Grimley, and Watanabe 1993 Mass spectroscopy is used in protein mass mapping Siuzdak, Bothner, Fuerstenau, and Benner 1996-2001 Mass spectroscopy is used in intact viral analysis Source: Borman, S. et. al., 2003; p.49 The technique of mass spectroscopy has progressed significantly during the last two decades, and this has helped in the development of new applications and instrumentation. (De Hoffmann and Stroobant, 2002; p.1) Nowadays, more applications are being discovered, such as its use in the field of drug discovery like genomics, proteomics, or pharmacokinetics. Mass spectrometry also plays a significant role in high throughput compound classification (Schalley, 2003; p. 285). High throughput screening is the most advanced technique in analytical technology. This particular method is widely used in the pharmaceutical and life-science industries ("NASA", 2001; p. 2). Mass spectroscopy has a number of significant uses. Geologists use it to date rocks, and pharmaceutical companies use it to determine the structure of novel compounds. Mass spectroscopy is a powerful technique used for separation processes such as gas chromatography, liquid chromatography, capillary electrophoresis, and supercritical fluid chromatography, due to its sensitivity and ability to classify chemical compounds successfully. The most common forms of hyphenated mass spectroscopy include gas chromatography/MS, liquid chromatography/MS, ion mobility spectrometry/MS, and tandem MS/MS. Gas chromatography/MS is used mainly to separate compounds. Liquid chromatography/MS is also used to separate compounds, but it differs such that its mobile phase is liquid instead of gas. Ion mobility spectrometry/MS is a technique where ions are first separated before being placed into the mass spectrometer. Lastly, tandem mass spectrometry/MS involves various steps of analysis, which are usually divided by fragmentation (De Hoffmann and Stroobant, 2002; p.1). Mass spectroscopy is a significant tool in the field of biochemistry. It helps in acquiring precise molecular weight measurements, reaction monitoring, amino acid sequencing, oligonucleotide sequencing, and in determining the structures of protein (Ashcroft, 2006; Course Notes). When a substance is analysed using this technique, the substance is positioned within a chamber, where it will be bombarded by a continuous flow of high-energy electrons. When this happens, the substance being analysed is divided into smaller portions, where some portions take on a positive charge, and the rest remain neutral. When these particles are combined, they are exposed to a magnetic field which will filter out the neutral ones and leave the positively charged ones, which are later dispersed depending on their mass to charge ratio. This results in a mass spectrum, a pattern of peaks which match up the structural characteristics of the material sample. The mass spectrum also gives information such as the initial molecular of the substance being analysed, and provides initial data of its molecular structure through its peaks (Flowers and Silver, 2004; p. 953). Mass spectroscopy seeks to create ions from both organic and inorganic compounds using any technique with the use of a mass spectrometer. A basic mass spectrometer is composed of the following: an ion source, a mass analyser, and a detector (Gross, 2004; p. 3). The most recent development in the field of mass spectroscopy is the capacity to record mass spectra from ordinary samples in their original environments, without initial preparations done to the samples. The use of mass spectroscopy to the classification of chemical compounds found in a mixture depends on the resolving power of the analyser. (Cooks, et. a.l., 2006; p. 1566) A mass spectrometer is a tool used to generate gas-phase ions, and separate them accordingly in their mass-to-charge ratios with the use of either electric or magnetic field in an empty field to count the number of ions present (Henderson and McIndoe, 2005; p.1). More modern spectrometers are now available. Most of them have the capacity to perform more than one analysis at the same time (Henderson and McIndoe, 2005; p.1). Mass spectrometers are tools used by various industries and the academe for commercial and research purposes. The various uses and applications of modern mass spectrometry include: in the field of biotechnology: the analysis of proteins, peptides, and oligonucleotides; for pharmaceutical purposes: drug discovery, combinatorial chemistry, pharmacokinetics, and drug metabolism; for clinical or medical purposes: neonatal screening, haemoglobin analysis, and drug testing; for environmental purposes: water quality and food contamination; and lastly, for geological purpose of examining the composition of oil deposits (Ashcroft, 2006; Course Notes). In a mass spectrometer, the analyser defines it effectiveness. The analyser is a portion of the spectrometer with a specific high vacuum capacity to propel extracted ions from sample substances to move through some type of electromagnetic field. These ions have different masses, velocities, and charge rates, and are moved by differently by the electromagnetic field found in the analyser (De Hoffmann and Stroobant, 2002; p.1). A representative schematic diagram of a mass spectrometer is illustrated below. Figure 1. Diagram of a mass spectrometer. Sample materials are presented, which are then bombarded with a stream of electrons. This results in positively charged ions which pass through a magnetic field. The samples interact with the receptor which is based on their mass. (Image source: Advanced Molecular Biology Laboratory; "Mass Spectrometry" http://www.bioteach.ubc.ca/MolecularBiology/MassSpectrometry/index.htm) Mass spectrometers are now used in various processes like carbon dating and radioactive dating. When this technique is used together with the method called gas chromatography, it can be an impressive instrument which can detect traces of contaminants in aqueous solutions. Mass spectrometers are also found in spacecrafts and space satellites. They are used to identify the composition of materials intercepted found in space (Henderson and McIndoe, 2005; p.2). The technique of Raman spectroscopy is founded on the measurement of scattered electromagnetic radiation from irradiated matter (Ahuja and Alsante, 2003; p.16). Raman spectroscopy is a significant classical spectroscopic technique, which uses lasers. New techniques in Raman spectroscopy include induced Raman spectroscopy, surface-enhanced Raman spectroscopy, and coherent anti-Stokes Raman spectroscopy (Demtrder, 2003; p.3). Raman spectroscopy, like infrared spectroscopy, is a technique used in studying the vibrations and movements of both molecules and crystals, and the two methods are considered complementary. (Schrader, 2003; p. 884) The history of Raman spectroscopy dates back to 1928 when Sir Chandrasekhra Raman together with K.S. Krishnan experimented on inelastic scattering of light. The original experiment involved sunlight which was directed by a telescope to a sample. Another lens was near the sample to collect scattered rays. A series of optical filters were used to demonstrate the scattered rays with the altered frequency due to the incident light. This has become the basic principle of Raman spectroscopy (Smith and Dent, 2005; p. 2). Raman scattering, the basic principle that surrounds Raman spectroscopy, yields scattered photons with different frequencies from the source of radiation which causes it. The difference in their frequencies is related to the vibrational or rotational properties of the molecules from where scattering occurs (Ferraro, 2003; p.2). The early instruments and tools which were used in this technique involved a mercury lamp (as the source of light), a spectrograph to separate the different colours of scattered light, and photographic film to capture the spectrum. Initially, Raman spectroscopy is a limited technique due to the popularity of infrared spectroscopy, an absorption technique which is similar to the techniques employed by Raman spectroscopy. (Pelletier, 1999; p.2). Improvements were made to gradually enhance Raman instrumentation. Various elements were used to construct the perfect lamp, like helium, lead, zinc, and bismuth, but these produced low intensity light. In 1914, a mercury lamp was developed, but it was only in 1939 that mercury lamps became suitable for use in Raman technique. (Ferraro, 2003; p.1) In 1953, the first commercial Raman instrument was introduced to the market, making it more accessible to a wider range of users and applications. Lasers replaced the mercury lamp in the 1960s which offered more ease and precision in use. (Pelletier, 1999; p.2) At present, Raman technique uses instruments like Fourier transform spectroscopes which are widely available in the market (Ferraro, 2003; p.2). There are two main types of Raman instruments available in the market today: dispersive instruments and interferometric instruments. These two types of instruments are categorized according to their ability to efficiently handle low light levels, provide adequate resolution to gauge scattered spectra, and remove interference and stray light from the main laser light. (Cazes, 2005; p. 217) Below is a schematic diagram of a Raman spectrometer. Figure 1. Diagram of a Raman spectrometer. (Image source: http://www.chm.bris.ac.uk/pt/diamond/stuthesis/chapter2.htm) A Raman spectrometer has four basic components, namely, laser, optical sampling system, wavelength separator, and detector. The laser and other hardware are housed in a base unit, and the optical sampling system has the means to provide lighting on a sample material through the laser, and later collect the scattered light. Different Raman spectrometers have different excitation wavelengths, speed, and sampling machine used for specific sample materials (Slater et. al., 2001; p. 42). Initially, Raman instrumentation consisted of bulky tools which discouraged many from using the technique. It was only during the 1990s when its bulkiness was reduced and more enhancements were introduced, such as holographic notch filters, which are used to separate Raman signals, lasers, detectors, computers, and new software (Adar, et. al., 2004; p. 22). Raman instrumentation is now applied to a wide range of applications. The Fourier transform technique gave Raman spectroscopy credibility, and it has been used by the analytical community since then (Adar, et. al., 2004; p. 22). The applications of Raman spectroscopy include a vast range of practical uses in both physics and chemistry. The Raman Effect is easily controlled and may only appear as part of the visible spectrum since Raman lines are dependent on the frequency of incident radiation. (Yadav, 2005; p. 121) Raman spectroscopy is used in chemistry because vibrational information is importance for the chemical bonds found in molecules. It provides a specific fingerprint through which a molecule can be identified. Another use of this technique is in the study of changes in chemical bonding, such as when substrates are added to certain enzymes. In physics, conventional Raman spectroscopy is used to differentiate various materials, calculate temperature, and obtain the crystallographic orientation of a specific sample (Ferraro, 2003; p. 162 and Yadav, 2005; p. 121). The main advantage of the Raman technique lies on its high level of specificity, which comes from its association with the material sample to be analysed. Raman spectrum is highly specific, thus allowing direct and easy identification of the sample material (Mitra, 2003; p. 415). Surface-enhanced Raman spectroscopy can be acquired when a sample is adsorbed near a rough metal surface, such as gold, silver, or copper. This technique can be used in analytical sensitivity, molecular selectivity, minimization of background fluorescence, and sensitivity with regards to the distance between the adsorbate and surface (Menzel, 1995; p. 185). Surface-enhanced Raman spectroscopy is a method used to acquire strong Raman signals to be used on various surfaces. Developed in 1974, this technique requires the adsorption of material samples to be analysed onto rough metal surfaces where the roughness dictates the atomic level. (Skelley et. al., 2005; p. 302) This technique has helped catalyse studies of condensed parts on surfaces. It showed significant promise as vibrational probe of in situ gas-solid, and solid-solid phases, and as high resolution probe of vacuum-solid environments. (Ferraro, 2003; p. 162) Coherent anti-Stokes Raman spectroscopy is related to directional signal called the anti-Stokes scattering. This technique is significantly useful in diagnostic applications of combustions and plasmas, especially if non-invasive means of probing samples are preferred. (Menzel, 1995; p. 186) Coherent anti-Stokes Raman spectroscopy uses two laser beams with different frequencies are exposed on a Raman medium with a definite crossing angle, where the difference in the frequencies of the two beams across the Raman range of the medium gives off the Raman-enhanced coherent anti-Stokes emission (He and Liu, 2003; p 397). Coherent anti-Stokes Raman spectroscopy is a method which was discovered in 1962 by Woodbury and Ng when they were conducting work on a megawatt pulsed ruby laser with a nitrobenzene Kerr cell. (Menzel, 1995; p. 186) The technique of coherent anti-Stokes Raman spectroscopy is more advantageous than traditional Raman spectroscopy due to the former's high intensity and separation from fluorescence. These shorten a sample's exposure time, while traditional Raman spectroscopy requires longer exposure time. (Furukawa, 2004; 10) Mass spectroscopy and Raman spectroscopy are techniques used to discover the molecular structures of new chemical substances (Flowers and Silver, 2004; p. 953). Both spectroscopic techniques including all the remaining spectroscopic methods are useful in the fields of atomic and molecular physics, chemistry, and molecular biology. Results from using both techniques are called spectra, and are presented in graphical forms (Demtrder, 2003; p.1). Mass spectroscopy and Raman spectroscopy both use instrumentation to obtain a spectrum which illustrates the results of each technique (Tanabe, 1999; p. 35l; and De Hoffmann and Stroobant, 2002; p.1). Mass spectrometers are instruments used to measure molecular masses (see Figure 1). (De Hoffmann and Stroobant, 2002; p.) Raman spectrometers measure the vibrations and rotations of molecules and crystals (Adar, et. al., 2003; p. 34). The main difference between mass spectroscopy and Raman spectroscopy lies in the fact that the former uses absorption technique, while the latter uses the principle of scattering. Mass spectroscopy uses the principle of fragmentation, while Raman spectroscopy is concerned with scattering (Flowers and Silver, 2004; p. 953). Mass spectroscopy measures the molecular mass of a sample, while Raman spectroscopy measures the wavelength and intensity of inelastic scattered light found in molecules. A mass spectrum is a graphical presentation of ion intensity as a mass-to-charge ratio function. These graphs are records of ions and their strength which helps to determine the molecular weight and structure of the sample substance being mass analysed. (Ashcroft, 2006; Course Notes) A Raman spectrum, on the other hand, is a vibrational spectrum and the changes in the vibrational modes can be observed in situ. These changes include transitions, reaction, and changes in structures. The strength of Raman scattering increases depending on the strength of the laser used. (Tanabe, 1999; p. 35) The methods being used in mass spectroscopy is different from the methods of other spectroscopic techniques because mass spectroscopy does not use the principle of absorption. (Flowers and Silver, 2004; p. 953) It is a technique used to measure the molecular weight of a sample material, and the results determined by this technique are largely dependent on the resolution of a mass spectroscope's analyser. This technique also depends on the chemical reactions in the gaseous phase of ions, where molecules are consumed during the formation of ions. The sample material to be analysed is destroyed in the process by the mass spectrometer. (Mellon et. al., 2000; p. 3). Mass spectroscopy is also useful in differentiating molecules with little differences in molecular weight (Ahuja and Alsante, 2003; p. 16). Raman spectroscopy, on the other hand, is a spectroscopic technique that relies heavily on inelastic scattering of light. It studies and focuses on the vibrational behaviour and movements of molecules in a given sample, and provides excellent sample images. (Schrader, 2003; p. 884) As a spectroscopic technique, it uses the principle of absorption, and it measures the changes and amount of energy that molecules give off when they move from ground state to an excited level. (Smith and Dent, 2005; p. 2) Raman scattering is a form of molecular spectroscopy. Scattering is a technique which is commonly used Raman spectroscopy, and the main scattering technique that this type of spectroscopy uses is called Raman scattering (Smith and Dent, 2003; p. 3). The scattered light arises from the wavelengths that are moved from the incident light by the power of molecular vibrations and rotations. Spectroscopy has made outstanding contributions to the present state of physics, chemistry, biology, and astronomy. Highly specialized information on the molecular structures and interactions of molecules with their environment can now be easily generated through a variety of ways, ranging from the absorption spectrum or emission spectrum which are derived when electromagnetic waves interacts with matter (Demtrder, 2003; p.1). The wide range of applications for spectroscopic techniques and applications can now be found in most research laboratories, medical facilities, and industrial zones. Mass spectroscopy has helped chemists to obtain precise molecular masses, to verify the purity of a sample; monitor enzyme reactions and modifications; perform amino acid sequencing; and monitor protein structures (Henderson and McIndoe, 2005; p.1). Raman spectroscopy has been significantly useful in chemical analyses because it shows high specificity, demonstrates high compatibility with aqueous samples, does not require elaborate sample preparations, and short time period is required for experimentation ("Kaiser Optical Systems", 2001; p. 2). Since the initial discovery of a spectrum by Newton in 1666, spectroscopy has been used as an analytical tool in the fields of chemistry, physics, biology, pharmacokinetics, forensic science, and astronomy. Through time spectroscopy has helped scientists and researchers to identify the molecular structures of biomolecules; determine and quantify the presence of different compounds in mixtures; sequence proteins and oligosaccharides; determine the presence of drugs in a person's body; analyse pollutants in the environment; conduct forensic examinations; establish the composition of specimens from space, and determine the age and origin of samples in chemistry and archaeology. Spectroscopy has also been largely used in the field of astronomy. Modern telescopes contain spectrographs, which are used to calculate the chemical composition and physical properties of astronomical samples or to measure their velocities. (Ashcroft, 2006; Course Notes; Nier, 1998; pp 552-56, Flowers and Silver, 2004; p.953) Bibliography Adar, Fran, Coralie Naudin, and Andrew Whitley. 2004. Case Studies in the Application of Raman Microscopy. Raman Technology for Today's Spectroscopists. June 2004: 22-29. Adar, Fran, Gwenaelle Le Bourdon, John Reffner, and Andrew Whitley. 2003. FT-IR and Raman Microscopy on a United Platform: A Technology Whose Time Has Come. Spectroscopy. 18(2): 34-40, February 2003. Ahuja, Satinder, and Karen Mills Alsante (eds). 2003. Handbook of Isolation and Characterization of Impurities in Pharmaceuticals. California: Elsevier Science. Ardrey, Robert E. 2003. Liquid Chromatograhy-Mass Spectrometry: An Introduction. West Sussex: Wiley and Sons. Ashcroft, Alison E. 2006. An Introduction to Mass Spectrometry. Leeds: The University of Leeds [Course Notes] Borman, S., Hailey Russell, and Gary Siuzdak. 2003. A Mass Spec Timeline. Today's Chemist at Work (Chemistry Chronicles from the American Chemical Society). September 2003 pp. 47-49. Cazes, Jack H. 2005. Ewing's Analytical Instrumentation Handbook. 3rd Ed. New York: Marcel Dekker. De Hoffmann, Edmond and Vincent Stroobant. 2002. Mass Spectrometry: Principles and Applications. 2nd Ed. West Sussex: John Wiley and Sons. Demtrder, W. 2003. Laser Spectroscopy: Basic Concepts and Instrumentation. 3rd Ed. Berlin: Springer-Verlag. Ferraro, John R. 2003. Introduction to Raman spectroscopy. California: Elsevier. Flowers, James L. and Theodore Silver. 2004. Cracking the MCAT. New York: The Princeton Review Publishing. Furukawa, T. 2004. Biological Imaging and Sensing. Berlin: Springer-Verlag. Gross, Jurgen H. 2004. Mass Spectrometry. Heidelberg: Springer-Verlag. He, Guang-Sheng and Song H. Liu. 2003. Physics of non-linear Optics. Singapore: World Scientific. Henderson, William and Scott McIndoe. 2005. Mass Spectrometry of Inorganic and Organometallic Compounds: Tools - Techniques - Tricks. West Sussex: John Wiley and Sons Ltd. Kaiser Optical Systems. 2001. Raman Spectroscopy: An Overview. No. 1101. Mellon, F., R. Self, and J.R. Statin. 2000. Mass Spectrometry of Natural Substances in Food. Cambridge: The Royal Society of Chemistry. Menzel, E. Roland. 1995. Laser Spectroscopy: Techniques and Applications. New York: Marcel Dekker. Mitra, Somenath (ed.). 2003. Sample Preparation Techniques in Analytical Chemistry. New Jersey: John Wiley and Sons. National Aeronautics and Space Administration. Tech Briefs. June 2001. Nier, Keith A. 1998. A History of the Mass Spectrometer. From the "Instruments of Science: A Historical Encyclopedia." Robert Bud and Deborah Jean Warner (eds.) New York & London: The Science Museum, London, and The National Museum of American History, Smithsonian Institution, in association with Garland Publishing, Inc. Pages 552-56. Contributed on November 15, 1999 Pelletier, Michael J. 1999. Analytical Applications of Raman Spectroscopy. Oxford: Blackwell Publishing. Rennie, Gabriele. 2005. Exploring the Link between Diet and Cancer. Science and Technology Review. December 2005: 17-19. Robinson, James D., Eileen M. Skelley Frame, and George M. Frame II. 2005. Undergraduate Instrumental Analysis. New York: Marcel Dekker. Schalley, Christoph A. (ed.). 2003. Modern Mass Spectrometry. Berlin: Springer-Verlag. Schrader, Bernhard. 1973. Chemical Applications of Raman Spectroscopy. Angewandte Chemie (English Edition). 12(11):884-908, November 1973. Schramm, Alexander. "Advanced Molecular Biology Laboratory (BioTeach)" Mass Spectrometry. [Course Notes] Available: http://www.bioteach.ubc.ca/MolecularBiology/MassSpectrometry/index.htm. [7 April 2006] Slater, Joseph B., James M. Tedesco, Ronald C. Fairchild, and Ian R. Lewis. 2001. Raman Spectroscopy and its Adaptation to the Industrial Environment. (In Ian R. Lewis and Howell G.M. Edwards (eds.)) Handbook of Raman Spectroscopy: From the Research Laboratory to the Process Line. New York: Marcel Dekker. Smith, Ewen and Geoff Dent. 2005. Modern Raman Spectroscopy: A Practical Approach. West Sussex: John Wiley and Sons. Stuart, Barbara H. 2004. Infrared Spectroscopy: Fundamentals and Applications. West Sussex: John Wiley and Sons. Tanabe, Yoshikazu. 1999. Macro-molecular Science and Engineering: New Aspects. Berlin Heidelberg: Springer-Verlag Yadav, L.D.S. 2005. Organic Spectroscopy. Delhi: Anamaya Publishers. Read More