Development of Hydride Generation Methods for Atomic Spectroscopic Analysis

Abstract

Hydride generation has been utilized for over 100 years in both qualitative and quantitative procedures known as the Marsh reaction and the Gutzeit test, respectively, which deal with the determination of arsenic. This sampling technique may be used to separate and preconcentrate ana lyte(s) from sample matrices, thereby removing potential chemical and/or spectral interferences commonly en countered with direct solution analysis.The use of hydride generation in modern spectroscopic analysis began with the spectrophotometric determination of arsenic. One of the earlier procedures describes the generation of arsine by reaction of mossy zinc with an HCl/HjSO] mixture. The reaction products were bubbled into a solution containing ammonium molybdate hydrazine sulfate where the subsequent reaction formed a molybdenum heteropolyblue arsenic complex that gave a characteristic absorption spectrum ( / ). Since this procedure was described in 1951. a number of other similar spectrophotometric procedures involving hydride generation have been published.The rapid development of atomic absorption techniques of analysis resulting from its inherent specificity and sensitivity made it the technique of choice for many elemental analyses by the late L960's. Direct solution nebulization was almost exclusively used as the method of sample introduction. However, there were problems associ-

Standardized Techniques for the Collection and Analysis of Precipitation

“…Commercial apparatuses accept samples of 10 to 20 ml, resulting in detection limits for As and Se of 0.1 and 0.25 ppb in practice, which is too high in many cases (Robbins and Caruso 1979). Commercial apparatuses accept samples of 10 to 20 ml, resulting in detection limits for As and Se of 0.1 and 0.25 ppb in practice, which is too high in many cases (Robbins and Caruso 1979).…”