High-performance liquid chromatographic/mass spectrometric and high-performance liquid chromatographic/tandem mass spectrometric analysis of carbamate pesticides

The thermospray ionization mass spectra of selected carbamate pesticides were obtained using both single‐stage and triple‐stage quadrupole mass spectrometry in conjunction with high‐performance liquid chromatography. With the use of the single‐quadrupole mass spectrometer and ammonium acetate as the mobile phase, enhanced sensitivity for the analytes of interest was obtained by monitoring the relatively intact [M + 1]+ or [M + 18]+ adduct ions. Further structural characterization of the carbamates was not readily obtainable owing to the lack of diagnostic bond cleavages. The single‐stage quadrupole analyses were therefore complemented by triple‐stage quadrupole analyses. Here, collisionally activated daughter ion spectra exhibited structure‐specific fragmentations. In addition, the enhanced selectivity and specificity provided by tandem mass spectrometry allowed use of the technique as a rapid screening tool for carbamates without the need for the chromatographic separation step.