تسجيل الدخول

تسجيل

Sample preparation and presentation , Solvents

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  404

2026-11-08

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Sample preparation and presentation

Solvents

Solvents used in spectrophotometry must meet certain requirements to ensure successful and accurate results. The solvent chosen must dissolve the sample, yet be compatible with cuvette materials. The solvent chosen must also be relatively transparent in the spectral region of interest. To avoid poor resolution and difficulties in spec trum interpretation, a solvent should not be used for measurements near or below its UV cut off (i.e. the wavelength at which absorbance for the solvent alone approaches one absorbance unit). The cut-offs of common solvents are listed in Table 15.1. Once a solvent is selected on the basis of physical and spectral characteristic, its purity must be considered. The absorbance curve of a solvent, as supplied, should be smooth (i.e. have no extraneous impurity peaks in the spectral region of interest). Solvents especially purified and certified for spectrophotometric use are available from suppliers.