Organochlorine Pesticides In Water Research Articles

Quantitative screening of organophosphorus and organochlorine pesticides in water and soil using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

Organophosphorus and organochlorine pesticides, historically or currently widely used in agriculture, are prevalent in the environment and pose significant risks to public health and ecosystems. This study aimed to develop a robust analytical method for quantifying these pesticides in soil and water. By optimizing solid-phase extraction (SPE) and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedures, and utilizing comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF-MS), we achieved sensitive detection levels of all organophosphorus and organochlorine pesticides at 10 μg/kg for soil and 0.1 μg/kg for water samples. The mean recoveries were in the range of 74.2–118.3 % and 72.3–106.9 % at fortified concentration levels in soil and water, respectively. The method exhibited good linearity (R² ≥ 0.9874) and precision (relative standard deviations from 0.1 % to 29.9 %), providing a reliable approach for environmental monitoring and advancing the capabilities in pesticide residue analysis.

Porous covalent organic framework nanofibrous membrane for excellent enrichment and ultra-high sensitivity detection of trace organochlorine pesticides in water

Developing adsorbents with high performance and long service life for effective extracting the trace organochlorine pesticides (OCPs) from real water is attracting numerous attentions. Herein, a self-standing covalent organic framework (COF-TpPa) membrane with fiber morphology was successfully synthesized by using electrospun nanofiber membranes as template and employed as solid-phase microextraction (SPME) coating for ultra-high sensitivity extraction and analysis of trace OCPs in water. The as-synthesized COF-TpPa membrane exhibited a high specific surface area (800.83 m2 g−1), stable nanofibrous structure, and excellent chemical and thermal stability. Based on the COF-TpPa membrane, a new SPME analytical method in conjunction with gas chromatography-mass spectrometry (GC–MS) was established. This proposed method possessed favorable linearity in concentration of 0.05–2000 ng L−1, high sensitivity with enrichment factors ranging from 2175 to 5846, low limits of detection (0.001–0.150 ng L−1), satisfactory precision (RSD < 10 %), and excellent repeatability (>150 cycles), which was better than most of the reported works. Additionally, the density functional theory (DFT) calculations and XPS results demonstrated that the outstanding enrichment performance of the COF-TpPa membrane was owing to synergistic effect of π–π stacking effects, high specific surface area and hydrogen bonding. This work will expect to extend the applications of COF membrane to captures trace organic pollutants in complex environmental water, as well as offer a multiscale interpretation for the design of effective adsorbents.

Residual levels, phase distributions, and human health risks of OCPs in the middle reach of the Huai River, China.

Are the residues of organochlorine pesticides (OCPs) in freshwater in China still of concern after prohibition and restriction for decades? The scarcity of monitoring data on OCPs in freshwater in China over the past few years has hampered understanding of this issue. In this study, water and suspended particulate matter (SPM) samples were collected from the middle reach of the Huai River for OCP analyses. Residues of ∑OCPs in water and SPM ranged from ND to 8.6ng L-1 and 0.50 to 179ng L-1, with mean concentrations of 1.7 ± 1.3ng L-1 and 6.1 ± 31ng L-1, respectively. ∑HCHs (α-, β-, γ-, and δ-HCH) and ∑HEPTs (heptachlor and heptachlor epoxide) were the most predominant pesticides in the dissolved phase and SPM, respectively, accounting for 43 ± 35% and 27 ± 29% of ∑OCPs. HCHs and heptachlor epoxide mainly existed in the dissolved phase, while heptachlor mainly existed in SPM. The isomeric composition pattern of HCHs in water differed from that in SPM. Briefly, β-HCH dominated in water, while δ-HCH dominated in SPM. However, the composition pattern of DDT and its metabolites in water was similar to that in SPM. o,p'-DDD and p,p'-DDE dominated in both water and SPM. The ratios of α-/γ-HCH and (DDD + DDE)/DDTs indicated that HCHs and DDTs were mainly derived from historical residues. Risk assessments indicated that OCPs may not pose carcinogenic and non-carcinogenic risks to residents.

Deep eutectic solvent-based dispersive liquid–liquid microextraction for determination of organochlorine pesticides in water and apple juice samples

In this work, we developed a deep eutectic solvent-based dispersive liquid–liquid microextraction (DES-based DLLME) method for the extraction and preconcentration of organochlorine pesticides (OCPs) from water and apple juice samples. Different DESs were synthesized by mixing menthol with carboxylic acids such as acetic, formic, and lactic acids. Among them, DES synthesized by mixing menthol with formic acid at a molar ratio of 1:1 showed the highest extraction efficiency for the target OCPs compared to other DESs. Various parameters affecting the method's extraction efficiency, including volume of DES, ionic strength, and centrifugation rate and time, were optimized. Under optimum conditions, matrix-matched calibration curves were separately constructed using water and apple juice samples. The obtained calibration curves have exhibited wide linearity ranges for both matrices. The limits of detections (LODs) and quantifications (LOQs) of the method ranged from 0.01 to 0.04, and 0.10–0.14 ng mL−1 for water and 0.05–0.09 and 0.22–0.41 ng mL−1 for apple juice samples, respectively. Similarly, the trueness of the method studied by spiking the samples at three concentration levels showed recovery values ranging from 80.1 to 112.5 % for both water and apple juice matrices. The findings demonstrated that the proposed DES-based DLLME method is rapid, simple, and environmentally benign. Thus, it could be used as an alternative method for determining OCPs in water, apple juice, and other related matrices.

Distribution of organochlorine pesticides (OCPs) in surface-mixed layer water and intertidal sediments of Lagos lagoon, Gulf of Guinea

Organochlorinated pesticides (OCPs) were analysed in intertidal sediments and surface-mixed layer water of Lagos lagoon in Nigeria in order to elucidate the contamination levels, sources and distribution characteristics, and potential human and ecological health risks associated with exposures to OCPs. The total ∑ OCPs in sediments ranged from 222.35 to 2585.30 μg/kg dw, with a mean concentration range between 13.08 and 172.35 μg/kg dw, respectively. The most dominant OCP compounds in the sediments were dichlorodiphenylethanes (40%), chlors (26%), cyclodienes (17%), HCHs (9%), and endos (8%). The concentration (μg/kg) of individual ∑OCP groups in sediment decreased in the following order: ∑ dichlorodiphenylethanes > ∑ Chlors > ∑ Cyclodienes > ∑ HCHs > ∑ Endos. The ∑ OCPs in water ranged from 23.63 (mean concentration: 1.97 ng/L) to 172.05 ng/L (mean concentration: 13.23 ng/L). Dichlorodiphenylethanes (46%), cyclodienes (21%), chlors (14%), HCHs (12%), and endos (7%) were the most prevalent OCP compounds in investigated water samples. These locations are pollution hotspots for potential wastes arising from industrial effluents, heavy shipping activities, municipal wastes and discharges of transformer oil from abandoned power generation and transmission facilities. The total composition and β-, γ- and δ-HCH isomeric ratios suggest recent anthropogenic introduction of the HCHs into the lagoonal ecosystem compared to historical deposits. Dichlorodiphenylethanes (p,p′-DDD, p,p′-DDE, and methoxychlor) were ubiquitous except p,p′-DDT. Results indicate historical inputs of technical DDT with considerable biodegradation and photochemical transformations. Generally, the ∑ chlors in sediments and surface-mixed layer water samples decreased following heptachlor > heptachlor epoxide > α-Chlordane > γ-Chlordane. The α-chlordane/γ-chlordane ratios indicate a mix of recent commercial and historical chlordane contamination sources. Concentrations of most OCPs significantly exceeded sediment quality guidelines suggesting that toxicity to benthic-dwelling faunas is estimated to be likely.

Distribution, Sources, and Risk Assessment of Organochlorine Pesticides in Water from Beiluo River, Loess Plateau, China.

The Loess Plateau has been a focus of public discussion and environmental concerns over the past three decades. In this study, in order to investigate the effect of OCP pollution in water of the Beiluo River, concentrations of 25 OCPs at 17 locations in the water were examined. The results showed that the concentration of ∑OCPs in the water ranged from 1.76 to 32.57 ng L-1, with an average concentration of 7.23 ng L-1. Compared with other basins in China and abroad, the OCP content in the Beiluo River was at a medium level. Hexachlorocyclohexane (HCH) pollution in the Beiluo River was mainly from the mixed input of lindane and technical HCHs. Dichlorodiphenyltrichloroethane (DDT) pollution was mainly from the mixed input of technical DDTs and dicofol. Most of the OCP pollution came from historical residues. The risk assessment results showed that hexachlorobenzene (HCB) and endosulfan had high ecological risks in the middle and lower reaches of the Beiluo River. Most residual OCPs were not sufficient to pose carcinogenic and non-carcinogenic health risks to humans. The results of this study can provide a reference for OCP prevention and control and watershed environmental management.

Pollution Characteristics of Organochlorine Pesticides in Water and Sediments of Huixian Karst Wetland in Guilin

Karst wetland plays an important role in the ecological environment; however, due to the existence of karst pipeline, pollutants can threaten the underground environment through the highly developed karst pipeline. Therefore, understanding the pollution characteristics of the karst surface environment is the premise of pollution ecological risk assessment and prevention. In this study, 24 organochlorine pesticides (OCPs) were analyzed to study the concentration, composition, source, and risk of OCPs in water and surface sediments in the Huixian Wetland of Guilin. The results showed that:the concentration of OCPs in water ranged from 3.17 ng·L-1 to 92.50 ng·L-1, and the concentration of OCPs in sediment ranged from 1.16 ng·g-1 to 219.52 ng·g-1, showing the main pollution characteristics of HCHs and DDTs. The concentration of OCPs in water was higher in the wet season than that in the dry season. The concentration of OCPs in sediments was higher in the dry season than that in the wet season. The isomer ratios revealed that OCPs in the study area were mainly derived from long-term degradation residues, and some sites had new input of lindane. Based on Monte Carlo simulation, the human health risk assessment of the study area showed that the 95% quantile carcinogenic risk of OCPs in water was greater than 1×10-6, with potential but acceptable health risk. The non-carcinogenic risk was lower than 1, which indicated that the level of OCPs residues in the water in the study area was not enough to cause non-carcinogenic risk to the human body.

Organochlorine pesticides and polychlorinated biphenyls in city drains in Makurdi, central Nigeria: Seasonal variations, source apportionment and risk assessment

A study of seasonal variation, sources and potential risks of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in open city drains in Makurdi, Central Nigeria was carried out. OCPs and PCBs were quantified using gas chromatograph-mass spectrometer. The total (∑8OCPs) concentrations (ngL−1) of OCPs in water was 2.99 with a mean ± SD of 0.75 ± 0.12 during wet season, while during dry season, the values were 11.43 and 2.86 ± 1.54 respectively. In sediment, the total concentration (ngg−1) of OCPs was 5270.66 with a mean ± SD of 1756.89 ± 450.01 during wet season and a total concentration of 5837.93 and the mean ± SD of 1945.98 ± 646.04, during dry season. Source apportionment of OCPs suggested historic application of the pollutants. The total (∑7PCBs) concentration (ngL−1) of PCBs in water was 0.24 with a mean ± SD of 0.03 ± 0.02 during wet season and a total concentration of 0.61 with a mean ± SD of 0.09 ± 0.11 during dry season. The total concentration (ngg−1) of PCBs in sediment was 37.88, mean ± SD of 5.41 ± 5.93 during wet season and a total of 47.07 and mean ± SD of 6.72 ± 7.27 during dry season. Ecological risk assessment based on effect range low (ERL) and effect range median (ERM) or threshold effect level (TEL) and probable effect level (PEL) that ecological risks were possible for some OCPs in this study, which calls for source control and remediation of the affected sites. Toxicity equivalency (TEQ) of PCB-118, the dioxin-like congener, indicated that it was most harmful to humans/mammals followed by birds, then fish.

Multi-level responses of oysters Crassostrea virginica for assessing organochlorine pesticides in a Ramsar coastal lagoon in southern Mexico

Organochlorine pesticides (OCPs) have been intensively used without proper regulation and control in Latin America due to the prevalence of diseases and pests, thus posing potential risks to nontarget organisms. Initiatives for ecosystem preservation, such as to designate protected areas, may not be enough to avoid contamination by OCPs, considering that protected areas tend to be permeable to diffuse sources. Here, we investigate multi-level responses of the oyster Crassostrea virginica to OCPs in Laguna de Términos, a RAMSAR coastal lagoon in the southern Gulf of Mexico. For this aim, OCPs occurrence and concentrations in the water, sediment, and in oysters from 3 settlement banks were assessed. Enzymatic and non-enzymatic biochemical biomarkers were quantified in the oysters’ mantle and digestive gland, and the human health risk due to oyster consumption was also evaluated. OCPs in water were below detection limits. Fourteen OCPs were detected in sediments (∑OCPs mean of 49 ngg−1) and 7 in oyster tissues (∑OCPs mean of 121 ngg−1). The occurrence of OCPs was related to the land uses along the watersheds of the rivers that drain into the lagoon. Biochemical responses were correlated with OCPs (∑HCH, ∑DDT, heptachlor and endosulfan) in sediment, and oyster tissues. OCPs in oyster tissues showed a strong association with pro-oxidant forces and oxidative stress responses (Superoxide dismutase, Catalase, Glutathione Peroxidase, and lipid peroxidation), and neurotoxicity (Acetylcholinesterase), suggesting that the current OCPs contamination exerts significant stress. Our study also shows that the consumption of oysters from the lagoon increases the potential human health risk. Considering that Laguna de Términos is a protected Ramsar site, we suggest that environmental protection measures should be increased and that a monitoring program for OCPs exposure is necessary to assess the effects on this ecosystem.

Effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction for determination of organochlorine pesticides in water by GC–MS

An effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction was introduced for determination of 13 organochlorine pesticides in water samples. In this method, a less toxic low-density organic solvent was used as extraction solvent. The extraction solvent was dispersed in to the aqueous sample via CO2 bubbles, in-situ generated up on addition of water to a falcon tube containing the mixture of effervescent powder precursors as well as the extraction solvent. Various experimental parameters such as effervescent and its weight fractions, extraction solvent type and its volume, the total mass of effervescent precursors, and the effect of salt were investigated and the optimal conditions were established. Under the optimum conditions, the proposed method exhibited good linearity for all target pesticides with the coefficient of determinations varying from 0.9981 to 0.9997. The limits of detection and quantification were within the range of 0.03–0.24 and 0.26–0.75 μg/L, respectively. The intra- and inter-day precisions which were expressed in terms of the relative standard deviation ranged from 0.33 to 4.47 and 0.51–5.52%, respectively. The enrichment factors and recoveries ranged from 24 to 293 and 76–116%, respectively. The proposed method could be used simple, cheap, fast, and environmentally friendly alternative for analysis of organochlorine pesticides from environmental water and other similar matrices.

The level and distribution of selected organochlorine pesticides in water of River Satluj Pakistan.

The study was aimed to identify different environmental factors (selected organochlorine pesticides) affecting the river water of Satluj. River Sutlej is about 1400 kilometers long and its water is extensively used for irrigation in Punjab, located both in India and Pakistan, which was also a reason of dispute between both countries for its water share. The study area was divided into four zones, Sulemanki Zone, Islam Zone, Mailsi Syphone Zone and Panjnad Zone. Liquid Liquid Extraction (LLE) technique was used for the collected water samples followed by high performance liquid chromatography (HPLC) UV-Visible detector The current finding revealed that aldrin was not detected during summer period in water samples of SZ-1 (Sulemanki Barrage), SZ-2 and SZ-3 (Maisli Siphon) of the study area. Lindane and DDE were found more in the samples of sediments from the study area at SZ-4 ranging from 2.238-8.226 ppb and 4.234-6.876 ppb, respectively. Heaptachlor (in sediments) was found to be0.032-234 ppb only at SZ-4.Endosulfan concentrations in water (winter) at SZ-3 was 0.06 ppb and at SZ-4,it was 0.05 ppb; dieldrin in water (winter) at SZ-4 was 0.0314 ppb and heptachlor was detected at SZ-1 (0.0315 ppb) and SZ-2 (0.0310 ppb) in water during winter season, were reaching to the Maximum Concentrations Limits (MCL), while all other residues investigated were found below the MCLin all the compartments of the study area set by various agencies like WHO/FAO- Codex Alimenterious. Present findings revealed that although the organochlorine pesticides are banned for agricultural use in many countries, including Pakistan, their presence in various samples might be due to illegal use of these pesticides in the study area and its neighboring regions. The overall study area comprises of mainly urban, suburban and agricultural land being the largest cotton growing area of the country. There is a need to take serious steps to minimize water pollution caused by pesticides to achieve a healthy lifestyle.

Application of the NU-1000 coated SPME fiber on analysis of trace organochlorine pesticides in water

Herein, a novel solid-phase microextraction (SPME) fiber based on the NU-1000 sorbent was developed for direct immersion extraction of organochlorine pesticides (OCPs) in water samples. As a kind of metal-organic framework, the NU-1000 possessed the mesoporous channels which were beneficial for the mass transfer of target analytes. Extraction equilibrium was achieved rapidly with the optimal extraction time of 30 min. The NU-1000 coated fiber with a high specific surface area showed better extraction efficiencies than commercial fibers (65 μm PDMS/DVB or 85 μm PA) towards OCPs, with the enrichment factors of the NU-1000 coated fiber 2–20 times higher than the latter. NU-1000 coated fiber showed higher extraction efficiencies toward polycyclic aromatic hydrocarbons (PAHs) than OCPs and nitrobenzenes. This indicated that π-π interaction and CH-π interaction between pollutants and aromatic groups of the NU-1000 contributed to the high extraction efficiencies. Under the optimal conditions (extraction at 40 °C for 30 min and desorption at 260 °C for 6 min), the NU-1000 coated fiber coupled with gas chromatography-mass spectrometry (GC-MS) exhibited satisfied analytical performance on analysis of OCPs, with a wide linear range (0.1–2000 ng L−1), low limits of detections (LODs, 0.011–0.058 ng L−1), and good reproducibility and repeatability. The established method has been successfully applied to the determination of OCPs in surface water with good sensitivity and recoveries, which proved the great promise of the NU-1000 on the extraction of organic pollutants with conjugated groups.

Seasonal monitoring of organochlorine pesticides in water, soil, and sediment in a small pond and determining ecotoxicological risk assessment

AbstractOne of the most important ways to improve quality and productivity in agriculture is to eliminate weeds, plant pathogens, and insects with pesticides. Although pesticides can effectively control agricultural quality and quantity, there are also lots of disadvantages due to their intensive usage resulting in degradation products. These products can accumulate in organisms and enter the food chain. Therefore, pesticides emanating from agricultural areas are agents that can affect the water quality of surface and groundwater sources. In this study, the presence of pesticides in the water and soil environment of the Borabey Pond and watershed which is situated north of Eskişehir, Turkey were determined by measurements. For this purpose, sediment and water samples from the pond and soil samples from the watershed were taken. The levels of organochlorine pesticides in the water, sediment and soil from Borabey Pond were determined between 0.5–13.8 ng/L, 0.03–1.02 μg/kg, and 0.54–52 μg/kg. Moreover, fugacity fraction has been measured that there is a transformation from water to sediment. Wilcoxon rank‐sum test is done to the seasonal measurements and there is no significant difference. Meanwhile, risk quotient (risk characterization ratio) estimates for DDTs and HCHs is below 1, so risk is acceptable.

Study of Organochlorine Pesticide Residues Analysis in Water, Fish and Sediment using GC-ECD in River Loko, Nasarawa State, Nigeria

Levels of organochlorine pesticide (OCPs) residues in sediment, water and fish in River Loko, Nasarawa State, Nigeria, were evaluated for possible pollution of the aquatic system. Water and sediment samples were collected from the river at 3 locations. Fish caught in the river were bought from fishermen at the bank of the river. The samples were collected in rainy season and preserved according to standard methods. Liquid-liquid extractions of samples were carried out, and then quantified using Gas Chromatography Coupled with Electron Capture Detector (GC-ECD). The OCPs levels ranged from 0.06 to 1.53 μɡ/Kɡ in sediment, 0.03 to 1.34 μɡ/Kɡ in water and 0.02 to 1.34 μɡ/Kɡ in fish. 2, 4-Dichlorophenoxacetic acid (2, 4-D) was the most accumulated OCP in sediment (1.64±0.10 μɡ/Kɡ), water (1.34±0.08 μɡ/Kɡ), and fish (1.34 μɡ/Kɡ). Concentrations of OCPs generally varied in the order of sediment &gt; water &gt; water ~ fish. ANOVA shows that concentrations of OCPs in water and fish were significantly (p ≤ 0.05) lower compared to sediment, except for mecoprop, imidacloprid, 2, 4-D, and aldrin, which were not significantly different in the samples. Pearson correlation matrix for OCPs in water and sediment show moderate to very strong and positive correlations except for mecoprop (-0.705), alachlor (-0.217), imidacloprid (-0.082), permethrin (-0.339) and aldrin (-0.795). Concentrations of OCPs were within the FAO/WHO acceptable limits except for aldrin, mecoprop, metolachlor, simazine, DDT and dieldrin. Regular monitoring of the quality of River Loko becomes necessary due to accumulation of OCPs.

Effervescent Powder-Assisted Dispersive Liquid-Liquid Microextraction Using Floating Organic Solvents for Determination of Organochlorine Pesticides in Water by GC-MS

Effervescent Powder-Assisted Dispersive Liquid-Liquid Microextraction Using Floating Organic Solvents for Determination of Organochlorine Pesticides in Water by GC-MS

Determination of organochlorine pesticides in water using GC combined with dispersive solid-phase extraction with single-walled carbon nanotubes

SummaryIn this study, single-walled carbon nanotubes (SWNTs) were used to determine organochlorine pesticides (chlorothalonil and pentachloronitrobenzene) in water using dispersive solid-phase extraction (DSPE), followed by gas chromatography (GC). The optimal adsorption conditions were determined by analyzing the effect of adsorbent dosage, adsorption time, eluent type and volume, and elution time. Under the optimal conditions, a good linearity was obtained at concentrations from 10 to 400 μg L−1 with correlation coefficients ranging from 0.9991 to 0.9986. The limits of detection (LOD) for the two organochlorine pesticides were 0.025 and 0.049 μg L−1, and the limits of quantification (LOQ) were 0.080 and 0.156 μg L−1, respectively. The accuracy of the proposed method was evaluated by measuring the recovery of the spiked samples, which ranged from 82.5% to 110.5% at spiking levels of 0.5–10 μg L−1 with relative standard deviations lower than 5.6% (n = 6). This method was successfully applied to determine the target analytes in canal water, drinking water, and water taken from the inlets and outlets of a wastewater treatment plant. The results demonstrate that the developed method has great potential for determining the two organochlorine pesticides in water samples.

Variation analysis of organochlorine pesticides in waters and sediments from a tropical river

In this paper, it is analyzed the temporal variation of organochlorine pesticides (OCPs) in water and sediments from a river influenced by the activity in an agricultural field in a tropical country during the period 2013-2016. The novelty consists of increasing the studies of concentrations of OCPs in water and sediments of rivers for contributing to establish thresholds of concentrations that allow to protect the biota in soils and waters. The mean values of the OCPs dissolved in water and sorbed on sediments varied as follows: p.p'-DDT (0.001 – 0.022 μg.L-1), (0.1 – 8.24 μg.kg-1), o.p'-DDT (0.001-0.021 μg.L-1), (0.51 – 5.76 μg.kg-1), p.p'-DDD (0.001-0.01 μg.L-1), (0.14 – 1.96 μg.kg-1), p.p'-DDE (0.001-0.027 μg.L-1), (0.52 – 7.32 μg.kg-1), o.p'-DDE (0.001-0.041 μg.L-1), (0.2 – 5.52 μg.kg-1), Aldrin (0.004-0.053 μg.L-1), (0.23 – 8.22 μg.kg-1), Dieldrin (0.001-0.032 μg.L-1), (1.13 – 6.82 μg.kg-1) and Endrin (0.001-0.008 μg.L-1), (1.16 – 7.60 μg.kg-1). The management of OCPs by the activity in the agricultural field is being controlled.

Simultaneous In Situ Extraction and Self-Assembly of Plasmonic Colloidal Gold Superparticles for SERS Detection of Organochlorine Pesticides in Water.

Rapid component separation and reliable surface-enhanced Raman scattering (SERS) detection of organochlorine pesticide (OCP) residues in real water samples remain major challenges because of sample complexity, trace content, and low molecular affinity for a metal surface. Here, we report a novel strategy of simultaneous in situ extraction and fabrication of plasmonic colloidal gold superparticles (AuSPs) to perform rapid SERS detection of OCPs in environmental water. In this protocol, multiple components of OCPs in complex water were facilely diffused into dichloromethane (DCM) microdroplets and specifically bound to octadecylamine-modified gold nanoparticles (Au-ODAs), affording the SERS substrate through self-assembly of the OCP-trapped Au-ODA into AuSPs with the evaporation of DCM. SERS signals of the specifically prepared Au-ODA could be used as an internal standard to calibrate the absolute signal of OCPs, and multiplex detection could be achieved depending on their molecularly narrow Raman peaks. As for simultaneously sensing four kinds of OCPs (4,4'-DDT, α-endosulfan, tetradifon, and chlordane) in water, the established method showed strong anti-interference ability and comparable quantification ranges with a low limit of detection (LOD). The recoveries ranged from 90.20 to 109.4% for OCPs in farmland, river, and fishpond water, indicating that the established AuSP-based platform is reliable and applicable to the detection of OCPs in real water samples.

Solid phase microextraction of organochlorine pesticides in water using MWCNTs-doped polypyrrole coated on steel fiber

The analysis of organochlorine pesticides (OCPs) residues has received an increasing attention in the last decades. Solid-phase microextration (SPME) is a convenient and fast analytical method, which has been widely used for the determination of volatile and semivolatile organic compounds in aqueous samples. The multiwalled carbon nanotubes/polypyrrole composite coating was used for the SPME of OCPs in water samples. The effects of various parameters on the efficiency of SPME process such as extraction time, extraction temperature, ionic strength, desorption time, and desorption temperature were studied. Under optimized conditions, the detection limits for the OCPs varied between 0.051 and 0.39 pg mL-1, the inter-day and intra-day relative standard deviations for various OCPs using a single fiber were 6.5-11.5% and 3.6-11.5, respectively. The linear ranges varied between 0.001 and 1 ng mL-1. The method was successfully applied to the analysis of ground water samples with the recoveries from 86 to 110%.

Determination of organochlorine pesticides in the surface water from Medjerda river, Tunisia

ABSTRACT In recent years there have been growing environmental concern, especially regarding the utilisation and discharge of toxic substances. Many organic pollutants are detected in aquatic ecosystems such as pesticides. Because they are large-scale production and usage, toxicity, bioaccumulation, and persistence in the environment, they cause harmful effects to organisms and human health. The Medjerda River is one among the main rivers in Tunisia and a number of other studies addressed the importance of this river regarding ecology, geochemistry, and sociology. The organochlorine pesticides (OCPs) were investigated in surface water samples from eight sampling sites in the Medjerda River. The extraction of water samples was performed by liquid-liquid extraction with hexane. Gas chromatography coupled to the mass spectrum (GC-MS) was used to perform qualitative and quantitative determinations. The levels of OCPs in water varied between 4.41 ng g−1 and 29.04 ng g−1. The Hexachlorobenzene (HCB) and ∑DDT are the most dominant compounds in different sampling sites. Distribution of HCB, ∑DDT, and other OCPs are different indicating different sources of contamination. The concentrations of OCPs in the water pose no threat to human and aquatic living species.