Comparison of Procedures for the Determination of Silicon in Atmospheric Particulate Matter

Flame atomic absorption photometry (AA), and emission spectroscopy (ES) were compared to the molybdenum blue spectrophotometric method (SP) for analysis of silicon in atmospheric particulate matter and in NBS standard reference materials. All techniques gave systematically low values, the range being 9-30% low with respect to the NBS values. Employing lithium metaborate as the fusion medium, the AA method proved to be approximately equivalent to the SP procedure in precision and accuracy. The ES technique displayed relatively poor accuracy and precision. Lithium metaborate provided substantially better solublization of the more refractory NBS standards compared to sodium carbonate.