In this undergraduate thesis, we conducted the qualification of modular spectrometer HR-6XR300-25 on examples of fluorescence and absorbance measurements of compounds of pharmaceutical importance – quinine sulfate, rhodamine B, riboflavin, fluorescein, salicylic acid, benzoic acid, and folic acid. We followed the example of the qualification of the modular spectrometer USB4000-UV-VIS. Qualification included qualifications of the light source, optical fibers, cuvettes, and spectrometric detector. In qualification of the light source, we determined acceptable baseline height with the deuterium or halogen lamp turned on, using both modular spectrometers with slits with diameters of 5 μm, 25 μm and 200 μm, in absorbance mode. We then recorded the emission spectra of both lamps and checked the stability of the baseline. We found that heating the deuterium lamp for at least 15 minutes before use and the halogen lamp for 30 minutes is necessary to achieve higher signal-to-noise ratio and more accurate wavelengths. In qualification of optical fibers, we found that the core diameter has a greater impact on light transmission than its length, and that used optical fibers of different lengths with core diameters of 400 μm and 600 μm are usable in the range above 260 nm, which is in accordance with the specification. From the cuvette qualification, we concluded that the declared areas of use matched the experimental ones. We first recorded the absorption and emission spectra of selected compounds using hybrid spectrometers and then compared them with spectra recorded using modular spectrometers, with the aim of proposing optimal recording settings that included the selection of the lamp, spectrometer, and slit, the setting of acquisition parameters such as Integration Time, Scans to average and Boxcar width and selection of the optical fiber combination. During the detector qualification, we determined the limit of quantification with empirical method and linear range for fluorescence and absorbance measurements of selected compounds with the proposed optimal recording settings. We were not able to obtain absorption peaks in the range below 300 nm for rhodamine B, riboflavin, fluorescein and folic acid, and emission peaks of benzoic and folic acid, with none of the modular spectrometers. Qualification of the spectrometric detector also included the verification and wavelength accuracy determination, from which we concluded that both spectrometers were properly calibrated and that we could measure accurate wavelengths using all three slits. We tested the repeatability of wavelengths and absorbances of absorption peaks and the repeatability of wavelengths and intensities of emission peaks of quinine sulfate and fluorescein.
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