Determination of tin in organotin compounds by hydride generation atomic absorption spectrometry in organic media

Abstract

A method is described for the determination of tin in organotin compounds (R_nSnX_4–n: R = butyl, phenyl; X = Cl, acetate, laurate; n= 2–4; and R₄Sn: R = phenyl). The compounds were initially treated with bromine in CCl₄ to separate the organic radicals bonded to tin. The reaction of the organotin compounds with bromine was of particular importance because the atomic absorption signal, without pre-treatment of the sample with bromine, depended on the organometallic compound studied. Hence, when R = butyl or phenyl, no atomic absorption peak was obtained, due to the low volatility of the alkyl (or aryl) tin hydrides formed (R_nSnH_4–n). Hydride generation atomic absorption spectrometry followed by direct atomisation in an electrically heated quartz tube was used for the determination. A detection limit of 1.5 ng ml^–1 of tin was obtained and the precision was 3% for the determination of 4 µg of tin (n= 7).