Absorbance Spectroscopy: Spectral Artifacts and Other Sources of Error

Synonyms
Deviations from Beer-Lambert Law; Light scattering; Solvent absorption; Spectrophotometric error; Stray light

Definition
Modern spectrophotometers and data-acquisition software are usually reliable and easy to use, but the spectra that they produce must always be regarded critically, as there are many possible sources of error and measurement uncertainty. Some of these relate to sample purity and identity. Others relate to the quality and calibration of the instrument, experimental technique, choice of sample cells and wavelength ranges, correct use of software for data acquisition and analysis, appropriate scan parameters that optimize signal-to-noise ratios yet ensure the fidelity of the recorded spectrum, and uncertainties associated with data analysis (e.g., the use of standard curves). A good understanding of spectroscopic principles, and proper instruction and supervision in the use of spectroscopic instrumentation, is essential for reliable spectroscopic work. Other...