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تسجيل

Instrument performance checks

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  415-416

2026-11-10

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Instrument performance checks

In fluorescence the calibration of excitation and emission monochromator wavelengths should be checked regularly by the use of sharp lines from the instrument’s own radiation source (e.g. xenon lines at 450.1, 462.4, 467.1 and 473.4 nm) or the use of sharp fluorescence peaks in solutions or glasses of trivalent lanthanide ions (terbium, europium). Other fluorescence standards in common use are ovulene and other polycyclic aromatic hydrocarbons with fine vibrational structures such as naphthalene and anthracene. In practice, it is necessary only to calibrate one monochromator, since the other can then be calibrated by the Rayleigh scattered radiation using a sample of colloidal silica in the sample position. The use of an auxiliary light source, such as a mercury light pen, is the least satisfactory method for wavelength calibration.