Determination of Carbetamide in Water by Micro Liquid-Liquid Extraction Followed by HPLC

Abstract

The validation of analytical procedures using added samples as reference materials is proposed. The carbetamide extracted with dichloromethane is monitored by reverse-phase high performance liquid chromatography with a retention time of some 2.7 min. while Carbaryl is used as an internal standard. The accuracy of the method is checked analysing water samples previously spiked with different amounts of analyte. A method to obtain the signal associated to a chromatographic blank is presented, to include as another precaution, within the calibration procedures. The method was applied to the determination of carbetamide at very low concentration levels (2.50-10.0 µg · L −1 ) in different types of natural water samples. The detection limit (DL) was 0.02 µg · L −1 . Around 100% recovery levels were customarily obtained in all cases. 355

Improvement in LC–MS calibration by addition of fragment signals

“…The chromatographic blank was estimated by direct integration of the background noise using extrapolated values of the base-peak width at concentrations different to zero. This method has been successfully applied in situations characterised by the absence of analytical signals related to the blank, as occurs with chromatographic techniques, electrophoretical techniques, and differential voltammetric techniques [11,13,14]. Additionally, this method has been used to estimate detection limits in the determination of carbetamide in water by micro liquid-liquid extraction followed by HPLC [15].…”