Speciation of trimethyllead and triethyllead by in-tube solid phase microextraction high-performance liquid chromatography electrospray ionization mass spectrometry

An analytical method has been developed for the determination of the trimethyl- (TML) and triethyllead (TEL) species in aqueous samples. In-tube solid phase microextraction (SPME) and high-performance liquid chromatography (HPLC) are coupled to a quadrupole mass spectrometer (MS) using electrospray (ES) as an ionization interface. Optimization of the instrumental parameters is described, including the evaluation of three commercial GC capillaries for the in-tube SPME experiments. The elemental (208Pb+) and molecular forms TML and TEL (m/z 253 and 295, respectively) were monitored simultaneously to provide complete speciation information. Results from the in-tube SPME-HPLC-ESMS experiments indicate that complete separation and detection of TML and TEL can be achieved in less than 5 min. Precision is greater than 5% and estimated limits of detection are 11.3 and 12.6 ng ml−1, respectively, for TML and TEL at a solution flow rate of 450 µl min−1.