HAPAB A thin-layer chromatographic method is presented for the quantitative and qualitative determination of organotin compounds by means of their quercetin chelates. The organotin compounds ( 5, 10 or 15 mcg tin ) were dissolved in octane/acetic acid or perosice-free diisopropyl ether/acetic acid ( 5:1 ) and spotted on thin-layer plates. After heating for 15 min at 80 degrees, the plates were developed after cooling with an appropriate eluant. Depending on the type of organotin compound to be analyzed, eluants consisted of organotin compound to be analyzed, eluants consisted of either: 1 ) benzene, ether and hydrochloric acid, 2 ) benzene, ether, acetic acid and water, 3 ) hexane and acetic acid or 4) benzene, hexane, ether and acetic acid. After development of benzene, hexane, ether and acetic acid. After development of the thin-layer chromatogram, the plate was heated for 20 min at 90 degrees and after cooling was sprayed with water and a 0.1% methanol-quercetin solution. The complexes were detected as yellow spots. The comples-containing absorptive layer was transferred to a reaction flask. For monooctyltin trichloride, the complex- containing absorptive layer was then shaken for 2 min with 0.1 of a 25% sulfuric acid solution, 4.0 ml of n-butanol and 1 ml of a 0.1% methanolic quercetin solution. After filtration, the extinction coefficient was determined and compared with a similarly prepared blank. The absorption maximum was determined at 443 nm. Modifications of this procedure are described for diethyltin dichloride, di-n butyltin dichloride, di-iso butyltin dichloride, di-(2- ethyl)-hexyltin dichloride, di-n-octyltin dichloride, dimethyltin dichloride, tri-n- butyltin chloride, tri-n-octyltin chloride and tetraoctyltin. It was observed that the specific extinction coefficient of the analyzed di- alkyltin quercetinchelates increased with increasing length of the carbon chain. For the very sensitive qualitative determination, the thin-layer chromatogram after spraying with water was treated with a 1% brenzcatechin-violet solution in acetone followed by a 5% malonic acid solution in 50% alcohol. The complexes were detected as blue spots. ANALYSIS 69/11/00, 415 1969
