Required knowledge includes: criteria for determining which IR technique (e.g. cell and accessory) is best suited to which type of sample (e.g. gas, liquid, bulk solid, fibre, film, small quantity) sample preparation procedures including specialised techniques such as: handling unstable/hazardous chemicals and samples, fragile/labile biological material and hygroscopic samples filtration or centrifugation to remove particulates prevention of personal contamination of samples by exposure to analyst cleaning and/or handling of optical elements: cleaning techniques and handling of transmission cells and flow cells cleaning of reflectance crystals and solid/liquid standards alignment techniques for source mirrors and accessories IR spectroscopic terms and concepts such as: absorption, absorbance, transmittance, diffuse and specular reflectance and attenuated total reflectance fourier transform of interferograms to produce spectra fast fourier transform (FFT) Fourier Transform advantages (Jacquinot, Felgett, Connes) electronic, vibronic, vibrational and rotational transitions during absorption and relationship to chemical properties concepts such as Beer's Law, Bouguer or Lambert's Law and molar absorptivity deviations from Beers Law, polychromatic radiation and chemical reactions spectral resolution, spectral bandwidth and linear dispersion limit of detection, limit of quantitation and their application to quality control procedures derivative spectra multi-component analysis analysis of reaction kinetics calculations and data processing involving: baseline correction and spectral smoothing Kubelka-Munk conversion (to linearise diffuse reflectance data) Kramer-Kronig transformation (to remove refraction effects) Concentration and dilution spectral matching spectral subtraction and spectral deconvolution first and higher derivatives of spectra multi-component quantitation techniques such as Classic Least Squares (CLS), Inverse Least Squares (ILS), Partial Least Squares (PLS), Principal Component Regression (PCR) operation, construction, selectivity, typical applications, troubleshooting and routine maintenance of IR systems including details such as: scan settings (source/detector/beam-splitter combination, number of scans, scan range, scan mode, aperture, resolution, apodisation, zero filling, optical alignment, sensitivity, threshold, optical path difference and velocity) sources (e.g.tungsten-halogen, ceramic, mercury arc, glow bars and Nernst glowers) interferometer components (e.g. beam splitters (KBr, CsI, Mylar and metal mesh) and mirrors sample transmittance (KBr, ZnSe and CsI cells), sample reflectance mounts and troughs, fibre optic probes and microscope attachments mid IR detectors (e.g. HgCdTe or MCT, DLaTGS), far IR detectors (e.g. DLaTGS, liquid helium cooled Si bolometers) IR sensitive charge coupled array devices and focal plane array detectors for imaging operation, construction, typical applications, troubleshooting and routine maintenance of IR accessories such as: attenuated total reflectance, single and multi-reflection unit and grazing angle specular and diffuse reflectance units single point microscope and spectrochemical imaging microscope photoacoustic spectroscopy (PAS) thermogravimetric analysers (TGA-IR) polariser calibration procedures for: accuracy of wavelength using transmission and reflectance standards, such as polystyrene, germanium and rare earth oxide glasses such as holmium oxide photometric accuracy using for example, polystyrene or polyethylene terephthalate and potassium dichromate zero absorbance baseline flatness sources of spectral interferences such as: water and carbon dioxide strongly absorbing matrix components computer control software for operating and optimising instrument procedures for optimising instrument performance such as: alignment of sub-systems (e.g. source mirror and beam splitter) and accessories adjustment signal to noise ratio to obtain satisfactory spectral resolution use of manual/computer calibration charts and/or standards to identify and quantify analytes such as: external calibration multi-component analysis semi-quantitative analysis library searching for spectral matching derivative spectrum analysis calculation steps to give results in appropriate units and precision troubleshooting and maintenance procedures recommended by instrument manufacturer enterprise and/or legal traceability requirements relevant health, safety and environment requirements
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