Reversed-phase ion-pair chromatography with inductively coupled plasma-mass spectrometry detection for the determination of organo-tin compounds in waters

A method for the determination of tributyltin (TBT) and triphenyltin (TPhT) in waters has been developed using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry. After evaluation of different column packing materials and mobile phases, a system using a 25 cmX4.6 mm I.D. column packed with Kromasil-100 5C(18) and a mobile phase of 82% (v/v) methanol, 2.5% (v/v) acetic acid, 0.3% (v/v) tetraethylamine and 10 mg l(-1) oxalic acid was developed. After preconcentration on a Sep-Pak C-18 mini-column a detection limit of 2 ng l(-1) for TBTCl was obtainable. It was found that ion-pairing agents were not necessary for the separation of the tri-substituted compounds. The reported method ensures the separation of the tri-substituted tins from the mono- and di-substituted forms.