Salting-out-assisted liquid–liquid extraction for the preconcentration and quantitative determination of eight herbicide residues simultaneously in different water samples with high-performance liquid chromatography
TL;DR: Salting-out-assisted liquid-liquid extraction coupled with high-performance liquid chromatography was developed for selective extraction and preconcentration of five s-triazine herbicides and three...
Abstract: Salting˗out-assisted liquid–liquid extraction coupled with high-performance liquid chromatography was developed for selective extraction and preconcentration of five s-triazine herbicides and three...
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TL;DR: The development of analytical methodologies and criticalities connected to determine pesticide residues in water matrices, including sampling, sample preparation approaches, instrumental analyses and specific applications emphasising those works published after 2015 are illustrated.
Abstract: In this review, we examined the European legislative context on water protection concerning pesticide residues monitoring and the relevant National Action Plans and strategies that were undertaken in European countries to better identify and manage the problem in water bodies. Furthermore, we illustrated the development of analytical methodologies and criticalities connected to determine pesticide residues in water matrices, including sampling, sample preparation approaches, instrumental analyses and specific applications emphasising those works published after 2015. Details about sampling strategies, analytical feasibility, official methods, degradation products and behaviour in the environment for a subset of 160 pesticides are also provided.
30 citations
TL;DR: A rapid, simple, and cheap analytical method, based on salting-out assisted liquid-liquid extraction coupled with UHPLC MS/MS detection for the accurate determination of CAP in honey to be used in routine analyses is proposed.
Abstract: Honey is a natural food widely consumed due to its high content in nutrients and bioactive substances. In order to prevent hive infections, xenobiotics such as pesticides and antibiotics are commonly used. Chloramphenicol (CAP) is a broad-spectrum antibiotic used to treat honeybee larvae diseases. However, CAP has toxic and nondose-dependent effects in sensitive subjects; for this reason, its use has been prohibited in food-producing animals, such as the honeybee. In this study, we proposed a rapid, simple, and cheap analytical method, based on salting-out assisted liquid-liquid extraction coupled with UHPLC MS/MS detection for the accurate determination of CAP in honey to be used in routine analyses. The parameters that influence the extraction efficiency have been optimized using an experimental design in order to maximize the recovery of the analyte by reducing the matrix effects. Therefore, the developed method was internally validated according to the 2002/657/EC Decision guidelines and applied to the analysis of 96 honey samples.
16 citations
Cites background from "Salting-out-assisted liquid–liquid ..."
...Basically, the addition of an electrolyte (or electrolyte mixture) allows the weakening or the disruption of the solvation forces between the organic solutes and the aqueous solvent in favor of the organic solvent [25,26]....
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TL;DR: In this paper, two types of polysiloxane polyether (DC 193C and OFX 0309) were studied to investigate the effectiveness of these surfactants toward atrazine in CPE method.
Abstract: Cloud point extraction (CPE) – spectrophotometric method had been adopted for the separation of atrazine using the non-ionic silicone surfactant, polysiloxane polyether, as a new approach of atrazine extractor in CPE. There were two types of polysiloxane polyether (DC 193C and OFX 0309) studied to investigate the effectiveness of these surfactants toward atrazine in CPE method. Various effects of operating parameters such as the concentration of surfactant and atrazine, addition of salt and change of temperature and pH on the extraction of atrazine have been studied in detail to find the optimum conditions. The limit of detections (LODs) and quantifications (LOQs) were in the range of 0.09–0.59 μg L−1 and 0.31–1.95 μg L−1 in water samples, respectively. The method recoveries at two spiked levels were 84–105% (CPE-OFX 0309) and 59–69% (CPE-DC 193C) with good correlation of determination (R2) ranging from 0.9927–0.9993 for both methods. The Langmuir isotherm has been used for solubilisation study of surfactant and atrazine. The thermodynamic parameters have been determined such as Gibbs free energy (ΔG°) which increases with temperature, value of enthalpy (ΔH°) and value of entropy (ΔS°) which increase with the surfactant hydrophobicity.
12 citations
TL;DR: In this paper, salting-out assisted liquid-liquid extraction combined with high performance liquid chromatography diode array detector (SALLE-HPLC-DAD) method was developed and validated for simultaneous analysis of carbaryl, atrazine, propazine, chlorothalonil, dimethametryn and terbutryn in environmental water samples.
Abstract: In this study, salting-out assisted liquid-liquid extraction combined with high performance liquid chromatography diode array detector (SALLE-HPLC-DAD) method was developed and validated for simultaneous analysis of carbaryl, atrazine, propazine, chlorothalonil, dimethametryn and terbutryn in environmental water samples. Parameters affecting the extraction efficiency such as type and volume of extraction solvent, sample volume, salt type and amount, centrifugation speed and time, and sample pH were optimized. Under the optimum extraction conditions the method was linear over the range of 10 - 100 μg/L (carbaryl), 8 - 100 μg/L (atarzine), 7 - 100 μg/L (propazine) and 9 - 100 μg/L (chlorothalonil, terbutryn and dimethametryn) with correlation coefficients (R2) between 0.99 and 0.999. Limits of detection and quantification ranged from 2.0 to 2.8 μg/L and 6.7 to 9.5 μg/L, respectively. The extraction recoveries obtained for ground, lake and river waters were in a range of 75.5% to 106.6%, with the intra-day and inter-day relative standard deviation lower than 3.4% for all the target analytes. All of the target analytes were not detected in these samples. Therefore, the proposed SALLE-HPLC-DAD method is simple, rapid, cheap and environmentally friendly for the determination of the aforementioned herbicides, insecticide and fungicide residues in environmental water samples.
12 citations
Cites background from "Salting-out-assisted liquid–liquid ..."
...In a conventional LLE, water immiscible organic solvents are commonly employed for facilitating efficient phase separation between the aqueous solution and non-polar organic solvents; the latter having low dielectric constant [21]....
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TL;DR: This research presents a novel probabilistic procedure that allows for direct measurement of the response of the immune system to earthquake-triggered landsliding.
Abstract: A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ioni...
3 citations
References
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TL;DR: A comprehensive review with 108 references referring to the distribution, source, accumulation, transformation, types and toxicity of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) is presented.
471 citations
449 citations
TL;DR: It was concluded that N-nitrosotriazines are unlikely to play a significant role in triazine-induced rat mammary gland tumors, and dietary exposure to atrazine is therefore extremely unlikely to result in human health hazard.
Abstract: A risk assessment of the triazine herbicide atrazine has been conducted by first analyzing the toxicity database and subsequently estimating exposure. Margins of safety (MOS) were then calculated. Toxicity was assessed in animal studies and exposure was estimated from occupational and dietary sources. In acute toxicity studies, atrazine caused developmental toxicity in the rabbit [no observed effect level (NOEL) 5 mg kg(-1) day(-1)] and cardiotoxicity in a dog chronic study (NOEL 0.5 mg kg(-1) day(-1)); cancer (mammary glands) resulted from lifetime exposure. The mammary tumors, which occurred specifically in female Sprague-Dawley rats, were malignant, increased in a dose-dependent manner and were also observed with other, related triazines. Evidence for a genotoxic basis for these tumors was either equivocal or negative. Triazines have been shown to be clastogenic in Chinese hamster ovary cells, in vitro, but without showing a convincing dose/response relationship. Atrazine can be converted into genotoxic N-nitrosoatrazine in the environment or the digestive system, suggesting that N-nitrosamines derived from triazines could be oncogenic. However, it was concluded that N-nitrosotriazines are unlikely to play a significant role in triazine-induced rat mammary gland tumors. An endocrine basis for the mammary tumors, involving premature aging of the female SD rat reproductive system, has been proposed. A suppression of the luteinizing hormone surge during the estrus cycle by atrazine leads to the maintenance of elevated blood levels of 17beta-estradiol (E2) and prolactin. The mechanism for tumor development may include one or more of the following: the induction of aromatase (CYP19) and/or other P450 oxygenases, an antagonist action at the estrogen feedback receptor in the hypothalamus, an agonist action at the mammary gland estrogen receptor or an effect on adrenergic neurons in the hypothalamic-pituitary pathway. None of these has been excluded as a target because there has been a lack of a rigorous attempt to address the mechanism of action for mammary tumors at the molecular level. The potential occupational exposure to atrazine was assessed during mixing, loading and application. Absorbed daily dosage values were 1.8-6.1 microg kg(-1) day(-1). The MOS values (animal NOEL/human exposure) for short-term (acute) exposure were 820-2800. Longer-term occupational exposure and risk were also calculated. Detectable crop residues are generally absent at harvest. Theoretical calculations of acute dietary exposure used tolerance levels, along with secondary residues, and water, for which there is a maximum contamination level; atrazine plus the three main chlorotriazine metabolites were combined. MOS values were above 2000 for all population subgroups. Dietary exposure to atrazine is therefore extremely unlikely to result in human health hazard. Recent publications have reported a possible feminization of frogs, measured in laboratory and field studies. This is assumed to be due to the induction of aromatase, but no measurements of enzyme activity have been reported. In field studies, the water bodies with the greatest numbers of deformed frogs sometimes had the lowest concentrations of atrazine. Other studies have also cast doubt on the feminization theory, except perhaps at very high levels of atrazine. Epidemiology studies have investigated the possibility that atrazine may result in adverse effects in humans. Although some studies have claimed that atrazine exposure results in an elevated risk of prostate cancer, the published literature is inconclusive with respect to cancer incidence.
150 citations
TL;DR: A new sample preparation technique, salting-out assisted liquid-liquid extraction with acetonitrile, for high-throughput good laboratory practice sample analysis using LCMS, which indicates that the method is rapid, reliable and suitable for regulated bioanalysis.
Abstract: Acetonitrile, an organic solvent miscible with aqueous phase, has seen thousands of publications in the literature as an efficient deproteinization reagent. The use of acetonitrile for liquid-liquid extraction (LLE), however, has seen very limited application due to its miscibility with aqueous phase. The interest in LLE with acetonitrile has been pursued and reported in the literature by significantly lowering the temperature of the mixture or increasing the salt concentration in the mixture of acetonitrile and aqueous phase, resulting in the separation of the acetonitrile phase from aqueous phase, as observed in conventional LLE. However, very limited application of these methods has been reported. The throughput was limited. In this report, we report a new sample preparation technique, salting-out assisted liquid-liquid extraction with acetonitrile, for high-throughput good laboratory practice sample analysis using LCMS, Two compounds from an approved drug, Kaletra, were used to demonstrate the extractability of drugs from human plasma matrix. Magnesium sulfate was used as the salting-out reagent. Extracts were diluted and then injected into a reversed phase LC-MS/MS system directly. One 96-well plate was extracted with this new approach to evaluate multiple parameters of a good laboratory practice analytical method. Results indicate that the method is rapid, reliable and suitable for regulated bioanalysis. With minimal modification, this approach has been used for high-throughput good laboratory practice analysis of a number of compounds under development at Abbott.
124 citations