Determination of insecticides in water using in situ halide exchange reaction‐assisted ionic liquid dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography

Abstract

A dispersive liquid-liquid microextraction (DLLME) method using in situ halide exchange reaction to form ionic liquid (IL) extraction phase was developed to determine four insecticides (i.e. methoxyfenozide, tetrachlorvinphos, thiamethoxam, and diafenthiuron) in water samples. The preconcentration procedure, followed by high-performance liquid chromatography and variable wavelength detectors (VWD), enabled the formation of the immiscible IL extraction phase; the insecticides were transferred into the IL phase simultaneously, which enhanced the efficiency and sufficiency, greatly shortening the operation time. The experimental parameters affecting the extraction efficiency including volume of extraction IL, extraction and centrifugation times, volume of the sample solution and exchanging reagent, and addition of organic solvent and salt were investigated and optimized. Under optimized conditions, the extractions yielded recoveries of the target analytes from 82 to 102%. The calibration curves were linear, and the correlation coefficient ranged from 0.9990 to 0.9999 under the concentration levels of 5-200 μg/L. The relative standard deviation (n=6) was 2.9-4.6%. The limits of detection (LODs) for the four insecticides were between 0.98 and 2.54 μg/L.

Phylogenetic and metabolic diversity of Tunisian forest wood-degrading fungi: a wealth of novelties and opportunities for biotechnology

“…In this sense, ligninolytic enzymes have been involved in the degradation of xenobiotic and recalcitrant aromatic compounds, industrial dyes (Khlifi et al 2009 ; Daâssi et al 2012 ), polycyclic aromatic hydrocarbons (PAHs) (Lee et al 2013 ), pesticides (Xiao et al 2011 ), dioxins (Sato et al 2002 ), chlorophenols (Li et al 2011 ), explosives (Cheong et al 2006 ) and kraft pulp bleaching (Moldes et al 2010 ).…”

Utilization of an ionic liquid in situ preconcentration method for the determination of the 15 + 1 European Union polycyclic aromatic hydrocarbons in drinking water and fruit‐tea infusions

“…Moreover, this IL has been the most used in in situ DLLME applications . Among the possible salts for use in the metathesis reaction with the IL, the salt Li‐NTf 2 has been mainly used in organic compound microextractions , while the salt Na‐PF 6 has been used mainly in metal microextraction . Therefore, Li‐NTf 2 was selected as the precursor salt, in equimolar ratio (1:1) with the IL.…”

“…This approach has been used for the determination of a number of metals in different samples . To date, the analytical applications of the in situ preconcentration method for organic compounds have been mainly developed for water, and they include the determination of a group of 13 aromatic analytes , a group of 17 pharmaceuticals , a group of six endocrine‐disrupting chemicals , and a group of insecticides . IL‐based surfactants instead of neat ILs have also been used with the in situ DLLME technique .…”

Comparison of two ultrasound‐enhanced microextractions combined with HPLC for determining acaricides in water

“…Determination of acaricides in water samples by UA‐IL‐DLLME and UA‐ISFME and combined with HPLC–UV is compared to other methods such as SPE combined with LC–MS, SPME combined with GC–MS, and liquid‐phase microextraction (LPME) combined with GC–μECD in Supporting Information Table S1. As can be seen, the UA‐IL‐DLLME and UA‐ISFME methods both possess lower LOD and shorter extraction times than most of the other methods.…”