determination of ametryn and chlorpyrifos pesticides in saffron using dispersive liquid–liquid microextraction followed by gas chromatography with the aid of chemometrics

Abstract: saffron, the world’s most expensive spice, is valuable for its color, taste and aroma properties, which are influenced by the postharvest treatments [1]. pesticides and herbicides are among the most priority pollutants to be monitored in a wide variety of matrices because their incorporation into water, soil, and crops may represent a serious hazard to human health and wild life. as a result, the quality control of saffron to achieve the healthiest production is incredibly considerable. plenty of efforts have been developed to determinate the amount of pesticides in complex matrices [2]. in the present study, dispersive liquid-liquid microextraction (dllme) is developed for extraction of a triazine herbicide, ametryn and an organophosphate pesticide, chlorpyrifos from saffron and simultaneous quantitative determination of them with gas chromatography-flame ionization detector (gc-fid). it should be noted that central composite design (ccd), multiple linear regression (mlr), and nelder-mead simplex optimization method were used in order to design, model, and optimize all of the effective factors of the extraction. accordingly, global optimum conditions were gained which were 40 μl of acetonitrile (disperser solvent), 40 μl of chloroform (extraction solvent), 20 minutes of sonication time and 3.0 % (w/v) nacl [3]. a multivariate calibration model using partial least squares regression (plsr) was built in concentration range of 10-100 ngml-1 of calibration samples and multivariate analytical figures of merit (afoms) were calculated for two pesticides. in the next section, these two pesticides were determined in saffron samples under optimized dllme-gc-fid and using plsr. it is concluded that the proposed method can reliably determine ametryn and chlorpyrifos in saffron close to their maximum residue limit (mrl).