Improved quantification of N-methylcarbamates combining supramolecular post-column derivatization-fluorescence detection-high performance liquid chromatography and partial least squares analysis

Abstract

A strategy to improve the simultaneous quantification of N-methyl-carbamate pesticides was performed. It takes advantage of the supramolecular interactions between the analytes and hydroxypropyl-β-cyclodextrin (HPCD) in the post-column reactor to increase the high-performance liquid chromatography-fluorescence sensitivity and use the partial least squares algorithm for the data analysis to identify strong overlap signals. The use of HPCD in the derivatization reactor generated a 50% of improvement in the limit of detection of Aminocarb (11.29 ng/mL), Carbofuran (CF) (19.58 ng/mL) and, Bendiocarb (BC) (0.27 mg/mL). It practically was the same for Carbaryl (2.35 ng/mL), but with a precise identification between CF and BC. The methods developed for these analytes were exactly on the elliptic joint confidence region. The recoveries in domiciliary water indicate the accuracy of the methodologies developed with values between 97% and 103% at the maximum concentration levels allow by international recommendations.