Development and validation of an ultrasound-assisted surfactant-enhanced emulsification microextraction method for liquid chromatographic determination of carbamate residues in fruit juices

Abstract

Summary.A microextraction procedure based on ultrasound-assisted surfactantenhanced emulsification microextraction (UASEME) was optimized and validated for preconcentration of carbamate pesticides prior to fast determination using high-performance liquid chromatography (HPLC) with monolithic column. The nonionic surfactant (Tween 20) was used as an emulsifier, and chloroform was selected as an extraction solvent. The experimental parameters affecting the extraction efficiency, such as the kind, concentration, and volume of surfactant, the kind of extraction solvent and its volume, salt addition, ultrasonic extraction time, and centrifugation time, were optimized. Under the selected UASEME and HPLC conditions, separation of five carbamate pesticides (carbofuran, carbaryl, isoprocarb, methiocarb, and promecarb) was achieved within 10 min. The linearity of the method was obtained in the wide range of 2-5000 μg L −1 , with correlation coefficients of 0.9931-0.9970. The limits of detection were in the range of 0.4-7.0 μg L −1 . The relative standard deviations (n = 5) were less than 0.59% and 4.86% for retention time and peak area, respectively. The enrichment factors of the developed UASEME method were in the range of 33-166. The fruit juice samples (at fortified levels of 0.25, 0.50, and 1.00 mg L −1 ) were successfully analyzed, and the relative recoveries were obtained in the range of 81-115%.

Fabrication of boron‐rich multiple monolithic fibers for the solid‐phase microextraction of carbamate pesticide residues in complex samples

“…Besides, the sensitivity obtained in this work is better than that obtained by other methods with the same kind of detector . It also can be seen from the comparison that the recoveries obtained in the present study are comparable with other mentioned methods . The comparison well demonstrates the proposed VPED/MMF‐SPME‐HPLC‐DAD method possesses some merits such as convenient operation, satisfactory sensitivity and eco‐friendliness, in the analysis of CPs.…”

“…However, the LODs achieved in the present method are lower than that achieved on SPE-HPLC-MS/MS [27] and LLME-MEKC-MS/MS [33]. Besides, the sensitivity obtained in this work is better than that obtained by other methods with the same kind of detector [21][22][23][24][28][29][30][31][32]. It also can be seen from the comparison that the recoveries obtained in the present study are comparable with other mentioned methods [21][22][23][24][25][26][27][28][29][30][31][32][33].…”

“…As shown, the consumption of organic solvent in the proposed method is at the same level as that used in micro-SPE (μ-SPE)-HPLC-UV [21], stir bar sorptive extraction-HPLC-UV [22], ultrasound-assisted surfactant enhanced mulsification microextraction-HPLC-UV [23], and less than other methods [24][25][26][27][28][29][30][31][32][33]. The consumed sample volume in the proposed method is slightly higher than that used it some reported methods [21][22][23][24]27,29,30,32,33], but far lower than that consumed in SPE-HPLC-MS/MS [25], SPE-HPLC-MS [26] and SPE-HPLC-UV [3]. Typically, for the determination of CPs, better sensitivity can be achieved when high sensitivity detector such as MS is used [25,26].…”