Application of 2-mercaptobenzothiatole-modified silica gel to on-line preconcentration and separation of silver for its atomic absorption spectrometric determination

2-Mercaptobenzothiazole-modified silica gel was used for the flow injection on-line preconcentration-separation and determination of silver by flame atomic absorption spectrometry, Two types of manifold, with one or two columns, were adopted, The results showed that Ag+ was selectively adsorbed from 0.05 to 6 M HNO3 solution and was readily desorbed by thiourea solution, The ions co-existing with Ag+ exhibit virtually no interference in the determination with the exception of Cl-, An Ag+ concentration as low as 1 ppb could be determined reliably if a long preconcentration time was used, The sample throughput was 60 h(-1) using the two-column manifold with a preconcentration time of 60 s, Silver in a geological sample, a copper metal sample and a lead nitrate sample was determined satisfactorily.