Comparison of sodium tetraethylborate and sodium tetra(n-propyl)borate as derivatization reagent for the speciation of organotin and organolead compounds in water samples

The influence of pH on the propylation with sodium tetra(n-propyl)borate of butyl- and phenyltins as well as for trimethyl- and triethyllead was inves tigated. Ethylation and propylation with tetraalkylborates were compared wi th regard to derivatization yields and figures of merit for organotin compo unds in real water samples. Similar results for limit of detection (3-12 ng /L as tin), derivatization yield (30-100%) and relative standard deviation of the method (3-10%) were achieved for derivatization with the two tetraal kylborates. Propylation is thus the preferred method for the simultaneous d etermination of environmentally relevant organotin and organolead compounds . The handling of the hygroscopic and air sensitive reagents NaBEt4 and NaB Pr4 was simplified by dissolving them in tetrahydrofurane. The reagent solu tions in tetrahydrofurane can be stored fur at least one month at 4 degrees C in the dark without observing any decrease in the derivatization efficie ncy.