SOLID-PHASE MICROEXTRACTION AS SAMPLE INTRODUCTION TECHNIQUE FOR RADIO-FREQUENCY GLOW-DISCHARGE MASS-SPECTROMETRY

Solid phase microextraction (SPME) was used for sampling and sample in troduction directly to a mass spectrometer with an rf glow discharge i on source (rf GDMS). Aqueous solutions of tetraethyllead (TEL) were an alyzed at 200 ppt concentration level. TEL was extracted by the SPME f ibre from the headspace of vigorously stirred samples. The analytes we re then flash desorbed from the fibre in a dedicated injector connecte d directly to the rf glow discharge ion source of a mass spectrometer. Flash desorption resulted in narrow peaks, with very good signal to n oise ratios. The spectra obtained could be used for both quantificatio n and compound identification based on the molecular fragment ions pro duced. TEL and tetramethyltin were also introduced together to the rf GDMS system. Both compounds produced very good spectra that could be u sed for quantification.