High resolution spectra of FeGePt multielement HCL A student will be performing analysis of water samples collected from the Lake Eymir to determine Fe concentration using a flame atomic absorption spectrometer (FAAS) equipped with Echellette-type of grating and Fe-Ge-Pt multielement Hollow Cathode Lamp (HCL) for which high-resolution emission spectrum is provided in the above spectrum. The monochromator of the instrument has a focal length of 100cm and a collimating mirror with a diameter of 3.5cm. The grove density of the monochromator is 2000 blaze /mm and 10.0mm of the grating surface is illuminated. Consider the figures and the information given above and answer the following questions: a) In this analysis, the student will be using the Fe emission peak of HCL, which appears at 193.7268nm. At what reflection angle(s) the first order and second order spectra of Fe with 193.7268nm wavelength will be observed? b) What would be the first-order and the second-order reciprocal linear dispersion of the spectrometer for the given parameters? c) What would be the first-order and second order resolving power of the monochromator? d) Discuss the advantages and disadvantages of first and second-order spectra and then decide which one should be used for the analysis. e) If the slit width is 0.1mm, can the monochromator resolve the 193.7268nm Fe emission line from Pt emission line (193.7424 nm)? If not, what slit width setting would be required to resolve these two lines? Consider only first-order reciprocal dispersion. Show your calculations and explain briefly. f) What is the light gathering power of the instrument? Compare the performance of the instrument in terms of S/N ratio with another instrument that has light gathering power, F, of f/4. g) Consider the figure given below and decide whieh one of the photocathode materials would be the most suitable material for the photomultiplier tube (PMT) that will be used for this analysis. Explain your choice briefly. Photocathode Spectral Responses