Simplified Apparatus for Routine Selective Spectral-Line Modulation Atomic Absorption Spectrometry.

摘要

A selective spectral-line modulation (SLM) atomic absorption instrument is described which exhibits the operational simplicity and reliability needed for routine analytical application. In this SLM design, a conventional pneumatic nebulizer/spray-chamber and slot-burner-supported flame form the modulating atom cell, and a mirrored chopper directs the continuum radiation alternately around or through this atom cell, thus performing the selective modulation function. The sensitivity and analytical curve linearity obtained for Ca and Cu with the present SLM system extend to an absorbance of about 0.3, approaching those obtainable using a line source within the same system. Detection limits found for a series of elements with the present SLM design are shown to be little improved over those for conventional, medium-resolution, continuum-source atomic absorption spectrometry. Important noise characteristics of the present SLM device are examined. (Author)