DETERMINATION OF BUTYLTIN ION SPECIES BY ION-EXCHANGE CHROMATOGRAPHY WITH INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRIC AND SPECTROFLUOROMETRIC DETECTION

Separation of mono-, di- and tributyltin (TBT) ions was accomplished by ion-exchange chromatography (Zorbax SCX 250 X 4.6 mm, 10 mum particle size) using a relatively little (30%) methanol containing eluent with 5% acetic acid and 0.05 M ammonium citrate. This low methanol content allowed sensitive detection by inductively coupled plasma mass spectrometry (ICP-MS) and micellar spectrofluorimetry after post-column reaction with morin in a Brij-35 micellar solution. Detection limits (3sigma) for TBT were 0.2 and 1.5 ng (as Sn), respectively, for 100 mul injection. Inductively coupled plasma atomic emission spectrometry (ICP-AES) was also tested as detection system with much lower sensitivity. The spectrofluorimetric method was applied to the determination of TBT in blind aqueous solutions supplied by the Community Bureau of Reference (BCR) of the EC after preconcentration on ODS cartridges and elution with a methanol-water-acetic acid mixture (80:17:3, v/v/v). The relative standard deviation ranged from 3 to 7% for 5 independent analyses of each of 4 samples and the accuracy obtained by the proposed method was satisfactory.