Improved Homogeneous Liquid–Liquid Extraction Combined with GC–ECD for the Determination of Organochlorinated Pesticides in Water

Abstract

In this study, improved homogeneous liquidliquid extraction (HLLE), equipped with GC-ECD has been developed for the extraction and determination of organochlorinated pesticides (OCPs) in water. The phase separation phenomenon occurred by temperature in a ternary solvent (water/methanol/chloroform) system. Several factors influencing the extraction efficiency were investigated and optimized with orthogonal array design. Furthermore, in this study, for the first time, before immiscible organic phase formation, different volumes of deionized water were subjected to homogeneous solution to investigate the effect of this factor on the extraction performance of HLLE. Optimal results were as follows: volume of the extracting solvent (chloroform), 50 lL; volume of the consolute solvent (methanol), 1.2 mL; volume of the sample, 2.5 mL; volume of the deionized water, 0.5 mL; time of centrifuge, 7 min. Under the optimum conditions, repeatability was obtained by spiking OCPs at concentration level of 20 lg L -1 , the RSDs varied between 4.8 and 10.7% (n = 4). The limits of detection of 0.02-0.12 lg L -1 were obtained for the OCPs. Enrichment factors and the extraction percent of the studied compounds were in the range of 240-300 and 69.2-84.0%, respectively. Finally, the results of the proposed HLLE method were compared with the same HLLE method without addition of deionized water. The results indicated that the proposed method has higher enrichment factors and lower detection limits.

Application of multivariate statistics in assessment of green analytical chemistry parameters of analytical methodologies

“…• K3 (39,35,33,32,31,38,37,34,30,36,4,5,3) formed by SPE methodologies together with three liquid-liquid extraction methodologies. SPE methodologies apply organic solvents and require additional material inputs (cartridges).…”

Polymethacrylate microparticles covalently functionalized with an ionic liquid for solid-phase extraction of fluoroquinolone antibiotics

“…Therefore, a suitable sample pretreatment is crucial to improving the purification and specificity before instrumental analysis [24]. Liquid-liquid extraction [25], solid-phase extraction (SPE) [26], dispersive liquid-liquid microextraction [27] and matrix solid-phase dispersion [28] are common sample pretreatments used routinely in pharmaceutical laboratories. Among them, SPE with different sorbents such as C 18 , C 8 , Silica, NH 2 , PCX, and HLB are the most frequently used.…”

Using silica coated magnetite nanoparticles modified with anionic surfactant aggregates as a solid phase microextraction adsorbent for determination of fluoroquinolones in egg samples by spectrofluorimetry

“…[26][27][28][29] Due to the complexity of biological sample matrices and the low level of the analytes, sample pre-treatment and pre-concentration are prerequisite steps for the determination of FQs. Several sample pre-treatment methods including liquid-liquid extraction, 30 dispersive liquid-liquid microextraction, 31 solid-phase extraction (SPE), 32 and matrix solidphase dispersion 33 have been proposed for the clean-up and concentration of FQs. Among these techniques, SPME is the most widely used because of its advantages of enrichment, simplicity, rapidity, organic solvent free, etc.…”