Dispersive liquid-liquid microextraction using a low density extraction solvent for the determination of 17 N-methylcarbamates by micellar electrokinetic chromatography-electrospray-mass spectrometry employing a volatile surfactant.

A new analytical method based on micellar electrokinetic chromatography tandem mass spectrometry (MEKC-ESI-MS/MS) employing a MS friendly surfactant (ammonium perfluorooctanoate) is proposed and validated for the identification and simultaneous quantification of 17 N-methylcarbamate pesticides in environmental and drinking water samples. MS/MS detection using an ion trap as analyzer operating in the multiple reaction monitoring mode was used. Different parameters were optimized in order to obtain an adequate CE separation combined with the highest sensitivity in MS/MS. Dispersive liquid-liquid microextraction (DLLME) using a low-density extraction solvent has been proposed for extraction, obtaining a preconcentration factor of 10. Under optimum conditions, recoveries for fortified samples ranged from 83% to 101%, with relative standard deviations lower than 8%. The limits of detection ranged from 1 to 144 ng l⁻¹, demonstrating the sensitivity and applicability of this fast, simple, and environmentally friendly method.