Partitioning Of Organochlorine Pesticides Research Articles

Spatio-temporal distribution of organochlorine pesticides in agricultural soils of southeast China during 2014-2019

Organochlorine pesticides (OCPs) are organic pollutants that are persistent and undegradable in the environment. To investigate their residual concentrations, spatial and temporal distributions, and the relationship with the crops planted, 12 individual OCPs in 687 soil samples from Jiangsu, Zhejiang and Jiangxi provinces of southeast China were examined. The detection frequencies of OCPs in the studied areas were 1.89%–64.9%. The concentrations of dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and endosulfans ranged from 0.01 to 5659 μg/kg, 0.03–3.58 μg/kg, and 0.05–3235 μg/kg, respectively. Jiangsu was mainly contaminated by p,p'-DDT, p,p'-DDD and endosulfan sulfate, Zhejiang was more polluted by OCPs except δ-HCH, and Jiangxi was more vulnerable to the contamination of OCPs except o,p'-DDE. The partial least-squares discrimination analysis (PLS-DA) model with RX2 36.3–36.8% revealed that compounds with similar chemical properties tended to appear in the same year and month. All crop lands were polluted by DDTs and Endosulfans. The highest concentrations of DDTs and Endosulfans were found in citrus and vegetable fields, respectively. This study offers new insight into the layout and partitioning of OCPs in agricultural land and into insecticide management on public health and ecological safety.

Occurrence and partition of organochlorine pesticides (OCPs) in water, sediment, and organisms from the eastern sea area of Shandong Peninsula, Yellow Sea, China

To evaluate the occurrence and partition of organochlorine pesticides (OCPs), hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs), water, sediment, and organisms were sampled from the eastern sea area of Shandong Peninsula (Yellow Sea, China) across all four seasons in 2016. There were three OCP hotspots in the sediment, mainly caused by the transportation of lindane and dicofol from adjacent Swan Lake and Guhe River. Waterborne OCP levels were highest in winter and lowest in spring, without vertical variability, suggesting that the Yellow Sea Cold Water Mass was governing the spatio-temporal distribution of OCPs in seawater. There was substantial accumulation of HCHs and DDTs in organisms via sediment, as indicated by the relatively low fraction of sedimental fugacity, high bio-sediment accumulation factor, and a positive linear correlation between logΣHCHs and trophic level. This is the first study that has focused on the accumulation of OCPs in entire sediment-seawater-organism system involving multi-phyla of species.

Seasonal variations of organochlorine pesticides (OCPs) in air samples during day and night periods in Bursa, Turkey

The goal of the present work was to investigate the seasonal variations of organochlorine pesticide (OCP) levels in Bursa, Turkey. The sampling site was a campus and considered as a semi-rural site. Atmospheric OCPs in the particulate and gas phases were measured separately during night and day time periods. The average of the total concentrations was determined as 599 ± 194 pg/m3 and on average 65% of the total OCP concentration was in the gas phase. Measured OCP level were comparatively greater in the warmer months of June, July, and August. The temperature dependence of gas-phase atmospheric concentrations of OCPs was examined using the Clausius-Clapeyron approach. The temperature effect was statistically significant (p < 0.05) on the Alpha, Gamma- and Delta-HCH, and Methoxychlor concentrations for night samples, yet it was not statistically significant for the day samples. The maximum annual average gas phase OCP concentration was measured for Beta-HCH species as 176 pg/m3. The maximum value was 67 pg/m3 in the particle phase and it belonged to Beta-Endosulfan. The partitioning of OCPs between particle and gas phases was studied. They were compared to the PoL (supercooled vapor pressure) and KOA (octanol/air partition coefficient) models. OCP concentrations measured during the day and night-time periods were found to be close to each other. The absence of a significant difference in night-day concentrations has shown that the impact of local sources were similar. Inhalation carcinogenic risks of OCPs were calculated and they indicated low cancer risk.

Measurement and modeling the gas/particle partitioning of organochlorine pesticides (OCPs) in atmosphere at low temperatures

The gas/particle (G/P) partition of organochlorine pesticides (OCPs) has been widely investigated and well documented, but rare at low temperature. In this study, seventy-four pairs of air samples in two sampling sites in northeastern China at a wide ambient temperature range of ~63 °C (−40 to +23 °C) were simultaneously collected in both gaseous and particulate phases and eighteen OCPs in these samples were measured and analyzed, among which, partition quotient (KP) values for fifteen OCPs were determined. Seven models including those have never been used for OCPs were applied to predict the values of KP, and the results were compared with the monitoring data for the fifteen OCPs. It was found out that, L-M-Y model provided advantages over the other models, with the best agreement to the monitoring data for analyzed OCPs (90.1 ± 11.1% data points within ±1 log unit, RMSE: 0.53 ± 0.18). The predicted maximum partition (MP) domain for eleven OCPs was observed with high values of their logarithm of octanol-air partition coefficient (log KOA > 12.5), where the log KP values become a constant (−1.53), indicating that the G/P partition of OCPs is in steady state but not the equilibrium. The Li-Ma-Yang (L-M-Y model) model, considering the wet and dry depositions of particles, elucidates the necessity of non-equilibrium term for the OCPs at low temperature. These results indicate that the L-M-Y model is valid for OCPs, which renders it highly promising for describing the partition behaviors in atmosphere for SVOCs, particularly at low temperature. An equation to calculate the condensation temperature TC was also derived, which gave a new understanding on the situation of chemicals with equal distribution between gaseous and particulate phases of OCPs and other similar SVOCs, especially in Polar Regions.

Significance of black carbon in the sediment–water partitioning of organochlorine pesticides (OCPs) in the Indus River, Pakistan

This study was conducted with the aim of assessing the levels and black carbon mediated sediment–water partitioning of organochlorine pesticides (OCPs) from the Indus River. ∑OCPs ranged between 52−285ngL−1 and 5.6–29.2ngg−1 in water and sediment samples respectively. However, the ranges of sedimentary fraction of total organic carbon (fTOC) and black carbon (fBC) were 0.82–2.26% and 0.04–0.5% respectively. Spatially, OCPs concentrations were higher at upstream sites as compared to downstream sites. Source diagnostic ratios indicated the technical usage of HCH (α-HCH/γ-HCH>4) and significant presence of DDT metabolites with fresh inputs into the Indus River as indicated by the ratios of (DDE+DDD)/∑DDTs (0.27–0.96). The partitioning of OCPs between the sediments and water can be explained by two carbon Freundlich adsorption model which included both organic carbon and black carbon pools as partitioning media.

The residues, distribution, and partition of organochlorine pesticides in the water, suspended solids, and sediments from a large Chinese lake (Lake Chaohu) during the high water level period

The levels of organochlorine pesticides (OCPs) in the water, suspended solids, and sediments from Lake Chaohu during the high water level period were measured by a solid-phase extraction gas chromatograph-electron capture detector. The spatial distributions of the three phases and the water/suspended solids and sediment/water partition coefficients were analyzed. The results showed the following: (1) The mean contents of OCPs in the water, suspended solids, and sediments were 132.4 ± 432.1 ng/L, 188.1 ± 286.7 ng/g dry weight (dw), and 13.7 ± 9.8 ng/g dw, respectively. The dominant OCP components were isodrin (85.1%) for the water, DDTs (64.4%) for the suspended solids, and both isodrin (48.5%) and DDTs (31.8%) for the sediments. (2) β-HCH was the primary isomer of HCHs in the water and sediments, and the proportions were 61.7 and 41.3%; γ-HCH was the primary isomer in the suspended solids, accounting for 49.3%; p,p'-DDT was the dominant content of DDTs in the water and suspended solids, whereas p,p'-DDD was the main metabolite of DDTs in the sediments. (3) The concentrations of contaminants in the water from the western lake were greater than those from the eastern lake, but the concentrations in the suspended solids from the western lake were less than those from the eastern lake. (4) There was no significant correlation between the water-suspended solids partition coefficient Kd and the n-octanol-water partition coefficient Kow, and between the sediment-water organic-C weighted sorption coefficients Koc and Kow.

Partitioning of organochlorine pesticides from water to polyethylene passive samplers

The mass transfer rates and equilibrium partitioning behaviour of 14 diverse organochlorine pesticides (OCP) between water and polyethylene (PE) passive samplers, cut from custom made PE sheets and commercial polyethylene plastic bags, were quantified. Overall mass transfer coefficients, k O, estimated PE membrane diffusion coefficients, D PE, and PE-water partitioning coefficients, K PE-water, are reported. In addition, the partitioning of three polycyclic aromatic hydrocarbons (PAHs) from water to PE is quantified and compared with literature values. K PE-water values agreed mostly within a factor of two for both passive samplers and also with literature values for the reference PAHs. As PE is expected to exhibit similar sorption behaviour to long-chain alkanes, PE-water partitioning coefficients were compared to hexadecane-water partitioning coefficients estimated with the SPARC online calculator, COSMO therm and a polyparameter linear free energy relationship based on the Abraham approach. The best correlation for all compounds tested was with COSMO therm estimated hexadecane-water partitioning coefficients.

Short-term variation in ambient concentrations and gas/particle partitioning of organochlorine pesticides in Izmir, Turkey

Abstract Twenty successive daytime and nighttime air samples were collected and analyzed for 23 currently used and/banned organochlorine pesticides (OCPs) between 14 and 23 May 2003 in Izmir, Turkey. Average individual OCP concentrations ranged from 5±4 pg m−3 (p,p′-dichlorodiphenyldichloroethane) to 391±306 pg m−3 (chlorpyrifos) and they were within the ranges previously measured at different sites. Most of the OCPs did not exhibit strong diurnal cycling. The temperature dependence of gas-phase atmospheric concentrations of OCPs investigated using Clausius–Clapeyron plots was statistically significant for β-HCH and endosulfan sulfate (p The partitioning of OCPs between particle and gas phases was investigated and compared to KOA (octanol/air partition coefficient) absorption model. The overall agreement between experimental and modeled log K p (gas/particle partition coefficient) values was good (p

Development of a Method for Extraction of Organochlorine Pesticides from Rendered Chicken Fat via Supercritical Fluoroform

Quantitative recoveries relative to liquid−solid extraction of organochlorine pesticides (OCPs) from rendered chicken fat were obtained using pure fluoroform as an extraction fluid. No cleanup procedure of the extract was employed prior to analysis via gas chromatography/electron capture detection (GC/ECD). Extraction of OCPs from rendered chicken fat was also performed with methanol-modified fluoroform. However, coextracted fat components were trapped along with the OCPs such that the GC/ECD trace of the extract showed a high background level which caused quantification to be less reliable. While no cleanup step nor activated alumina to retain fat in the extraction vessel was necessary, it was demonstrated that a longer extraction time was required to extract OCPs from fat using pure fluoroform than with methanol-modified fluoroform. Since little or no fat was extracted by fluoroform, the longer extraction time is believed to be caused by partitioning of OCPs between unextracted fat and fluoroform. Keywo...