Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dieldrin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed1978

Separation of polychlorobiphenyls from chlorinated pesticides in sediment and oyster samples for analysis by gas chromatography.

Polychlorobiphenyls (PCBs) have been separated from DDT and its analogs and from the other common chlorinated pesticides by adsorption chromatography on columns of alumina and charcoal. Elution from alumina columns with increasing fractional amounts of hexane first isolates dieldrin and heptachlor epoxide from a mixture of chlorinated pesticides and PCBs. The remaining fraction, when added to a charcoal column, can be separated into two fractions, one containing the chlorinated pesticides, the other containing the PCBs, by eluting with acetone-diethyl ether (25:75) and benzene, respectively. The PCBs and the pesticides are then determined by gas chromatography on the separate column eluates without cross interference. The method is applicable to sample extracts prepared for gas chromatography. Recoveries of the PCBs (Aroclors) and the chlorinated pesticides are good and the method is applicable to sediment and marine biota samples.

Chromatography, Gas↗
PubMed1977

Determination of chlorinated pesticides in potable water.

A procedure is described for monitoring organochlorine pesticides in potable water. Material adsorbed from water on to Amberlite XAD-2 macroreticular resin was eluted with n-hexane and the concentrated eluate was analyzed without further treatment. Electron capture (63Ni) gas chromatography utilizing a column of 4% QF-1 and 2% SE-30 on 80-100 mesh HP Chromosorb W at 180 degrees permitted identification of organochlorine pesticides and indicated the presence of phthalates. Confirmatory qualitative and quantitative analyses were done by specific ion-monitoring mass spectrometry. Levels determined in Ottawa drinking water were 17 ppt alpha-BHC, 1.3 ppt lindane, 0.7 ppt aldrin, and less than 0.05 ppt for each of heptachlor, heptachlor epoxide, dieldrin, endrin, chlordane, o,p'-DDT, p,p'-DDD, p,p'-DDT, and p,p'-DDE.

Chromatography, Gas↗
PubMed1991

Simultaneous separation and determination of hydrocarbons and organochlorine compounds by using a two-step microcolumn.

The simultaneous separation and determination of a mixture of hydrocarbons and organochlorine compounds was successfully carried out by using sorption chromatography on a two-step microcolumn of silica and aluminium oxide for their fractionation, and a dual detector system. In addition to the separation and identification of hydrocarbons and heterocompounds containing nitrogen, oxygen and sulphur atoms, separation and identification of chlorinated hydrocarbons (dichlorobenzenes, p-chlorotoluene, hexachlorobutadiene, 1,2,4-trichlorobenzene and 2-chloronaphthalene), pesticides (chlorpicrin, aldrin, lindane, alpha- and beta-benzene hexachloride (BHC), endrin, dieldrin, endosulphan, methoxychlor) and herbicides (propanil, dichlobenil, trifluralin, difolatan) were achieved in mixtures containing polychlorinated biphenyl, strobane and chlordane.

Chromatography↗
PubMed2002

Determination of organochlorine pesticides in seawater using liquid-phase hollow fibre membrane microextraction and gas chromatography-mass spectrometry.

The use of hollow fibre membrane microextraction in analytical chemistry has been increasing as the technique is a simple and efficient method for the extraction of trace organic compounds from environmental matrices. A simple liquid-phase microextraction technique using a hollow fibre membrane in conjunction with gas chromatography-mass spectrometry has been developed for the extraction and analysis of organochlorine pesticides (OCPs), i.e. alpha-hexachlorocyclohexane (BHC), lindane, beta-BHC, heptachlor, aldrin, dieldrin, endrin, endosulfan, p,p'-DDD, p,p'-DDT, endrin aldehyde and methoxychlor, from seawater. The technique requires minimal sample preparation time and solvent consumption, and represents a significant advantage over conventional analytical methods. Optimum extraction conditions have been evaluated with respect to sample pH, salt content and stirring rate, as well as solvent type and extraction time. A high level of detection linearity (coefficient of >0.9995, less than 14% RSD) was obtained for OCPs over a range of analyte concentrations between 5 and 100 microg l(-1), with detection limits in the parts per trillion (ppt) to sub-parts per billion range. Comparison between liquid-phase microextraction with hollow fibre membrane and US Environmental Protection Agency Method 508 showed that the novel method has comparable detection limits of between 0.013 and 0.059 microg l(-1) in seawater.

Gas Chromatography-Mass Spectrometry↗
PubMed2003

Fast supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection for multiresidue screening of organochlorine and organophosphorus pesticides in Brazil's medicinal plants.

A description is given of a rapid and environmentally friendly method to determine organochlorine and organophosphorus pesticide multiresidues--malathion, methidathion, fenitrothion, fenthion, parathion-ethyl, parathion-methyl, lindane, hexachlorobenzene, chlorothalonil, tetradifon, alpha-endosulfan, beta-endosulfan and dieldrin-in Passiflora alata Dryander and pasiflora edulis Sims. f. flavicarpa Deg. leaves by supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection (HRGC-ECD/FPD). The mild extraction conditions [pure CO2; 100 bar (1 bar = 10(5) Pa) and 40 degrees C (p = 0.62 g/ml); 5 min static+10 min dynamic extraction time; ODS trap and elution with 1 ml n-hexane at 2 ml/min] allow for direct analysis by HRGC-ECD/FPD with no prior cleaning procedure. The method provides. in accordance with the validation criteria of the European Pharmacopoeia, analytical results that are similar or even better than the official procedures, and is simpler, faster and cheaper. Mean recoveries of 69.8-107.1% were obtained, with 1.4-14.7% reproducibility (RSD). The method was applied to analyse commercial samples of Passiflora L. from Brazil. Twenty-three percent of the samples showed the presence of the organochlorine or organophosphorus pesticide residue investigated.

Chromatography, Gas↗
PubMed2003

Methods for selective determination of persistent organochlorine pesticide residues in water and sediments by capillary gas chromatography and electron-capture detection.

Different extraction methods were evaluated for the determination of fifteen organochlorine pesticides (OCPs) in water and sediments. Liquid-liquid extraction (LLE) was evaluated for the pesticides analyses in water while Soxhlet extraction (SE) and microwave assisted extraction (MAE) methods were compared in sediment. Of all the extracting solvents used, dichloromethane gave the best results. Percentage recoveries ranged from 71.03 +/- 8.15 (dieldrin) to 101.25 +/- 2.17% [a-benzenehexachloride (alpha-BHC)] in water with LLE. In sediments the percentage recoveries with Soxhlet extraction method varied between 88.22 +/- 7.85 (endrin) and 109.63 +/- 5.10% (beta-BHC) and ranged from 74.11 +/- 9.82 (2,4 DDT) to 97.50 +/- 4.56% (alpha-BHC) with MAE. The limits of detection for the OCPs ranged from 5.5 to 20.6 ng/l and between 0.6 and 2.1 ng/g. respectively. The LLE and the SE methods were applied to water and sediments samples, respectively, from marine and freshwater sources in the Eastern Cape Province of South Africa that receive runoffs from agricultural lands and effluents from industries. The levels of OCPs ranged from 5.5 (2,4-DDD) to 450 +/- 0.10 ng/l (beta-BHC) in water samples and from 0.6 (aldrin and 2,4-DDD) to 184 +/- 0.12 ng/g (beta-BHC) in sediments for triplicate analyses. Some endocrine disrupting OCPs such as DDT, DDE, heptachlor, endosulphan and the chlordanes were detected.

Chromatography, Gas↗
PubMed2003

Screening and determination of pesticides in soil using continuous subcritical water extraction and gas chromatography-mass spectrometry.

In the present work the efficiency of water under subcritical conditions for the extraction of pesticides having a broad spectrum of polarities from soils was evaluated. The pesticides under study were carbofuran, hexachlorobenzene, dimethoate, simazine, atrazine, lindane, diazinon, methylparathion, alachlor, aldrin-R, metholachlor, chlorpyrifos, heptachlor epoxide, dieldrin, endrin, 4,4-DDT and metoxichlor. Optimization studies were carried out using a blank soil (Non-Polluted Soil 1, CLN-1, RTC) and a real soil which were previously spiked with the pesticide mixture and aged for 60 days. A laboratory-made aluminum oven with controlled temperature was used to carry out the leaching process with subcritical water, where it is placed a pre-heater and the extraction cell. The following variables were studied, keeping the pressure controlled about 1200 p.s.i.: the extraction temperature, the time of static and dynamic extraction and the flow-rate of water (1 p.s.i. = 6894.76 Pa). The extraction efficiency of the pesticides increases with the temperature trending to the quantitative extraction at temperatures near to 300 degrees C. After the extraction process, the analytes were transferred quantitatively to 5 ml dichloromethane, before the determination by GC-MS. The results indicate that under the optimized conditions mostly of the analytes are extracted quantitatively in 90 min with recoveries quite similar to those obtained by the standard Soxhlet extraction procedure. Alternatively, by using an extraction time of 25 min, the method can be used as screening for all the pesticides, with recoveries depending on their polarity.

Gas Chromatography-Mass Spectrometry↗
PubMed2003

Determination of organochlorine pesticides in water using microwave assisted headspace solid-phase microextraction and gas chromatography.

A coupled technique, microwave-assisted headspace solid-phase microextraction (MA-HS-SPME), was investigated for one-step in situ sample pretreatment for organochlorine pesticides (OCPs) prior to gas chromatographic determination. The OCPs, aldrin, o,p'-DDE, p,p'-DDE, o,p'-DDT, p,p'-DDT, dieldrin, alpha-endosulfan, beta-endosulfan, endosulfan sulfate, endrin, delta-HCH, gamma-HCH, heptachlor, heptachlor epoxide, methoxychlor and trifluralin were collected by the proposed method and analyzed by gas chromatography with electron-capture detection (GC-ECD). To perform the MA-HS-SPME, six types of SPME fibers were examined and compared. The parameters affecting the efficiency in MA-HS-SPME process such as sampling time and temperature, microwave irradiation power, desorption temperature and time were studied to obtain the optimal conditions. The method was developed using spiked water samples such as field water and with 0.05% humic acid in a concentration range of 0.05-2.5 microg/l except endosulfan sulfate in 0.25-2.5 microg/l. The detection was linear over the studied concentration range with r2>0.9978. The detection limits varied from 0.002 to 0.070 microg/l based on S/N=3 and the relative standard deviations for repeatability were <15%. A certified reference sample of OCPs in aqueous solution was analyzed by the proposed method and compared with the conventional liquid-liquid extraction procedure. These results are in good agreement. The results indicate that the proposed method provides a very simple, fast, and solvent-free procedure to achieve sample pretreatment prior to the trace-level screening determination of organochloride pesticides by gas chromatography.

Chromatography, Gas↗
PubMed2003

Stir bar sorptive extraction and large volume injection gas chromatography to determine a group of endocrine disrupters in water samples.

Stir bar sorptive extraction (SBSE) combined with gas chromatography (GC) with mass spectrometric detection (MS) has been applied to determine a group of suspected endocrine disrupters in water samples. One centimeter stir bars coated with PDMS were used to extract the analytes and then solvent desorption was carried out. The absorption and desorption parameters in SBSE were optimized and large volume injection was used with a programmed temperature vaporizer injector (PTV) in GC to enhance the sensitivity of the method. The linear range of some endocrine disrupters was between 0.05 and 5 microg l(-1) and limits of detection were 0.01-0.24 microg l(-1) under full scan acquisition mode. The repeatability and reproducibility of the method (n = 5) for Ebro river water samples spiked at a level of 0.5 microg l(-1) was below 13 and 23%, respectively. Recoveries between 42 and 96% were obtained with the exception of atrazine. The method was applied to analyze real water samples from the Ebro River and irrigation streams of Ebro Delta and some of the compounds studied (aldrin, dieldrin, 4,4'-DDE and 4,4'-DDT) were found in some of them between detection and quantification limits.

Chromatography, Gas↗
PubMed1999

Supercritical fluid extraction and clean-up of organochlorine pesticides in Chinese herbal medicine.

A method involving the simultaneous extraction and clean-up of 13 organochlorine pesticides (OCPs) from Chinese herbal medicines (CHMs) was developed using supercritical fluid extraction (SFE) followed by gas chromatography-electron capture detection and mass spectrometric confirmation. The pesticides in the study consisted of alpha-, beta-, gamma-, and delta-benzene hexachloride, heptachlor, aldrin, heptachlor epoxide, endosulfan I, 4,4'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethene), dieldrin, endrin, 4,4'-DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane), endosulfan II, 4,4'-DDT (2,2-bis(p-chlorophenyl)1,1,1-trichloroethane), endrin aldehyde, and endosulfan sulfate. A series of experiments was conducted to optimize the final extraction conditions [pure CO2, 250 atm extraction pressure (1 atm = 101,325 Pa), 50 degrees C extraction temperature, 5 min static extraction time, 20 min dynamic extraction time, 2.0-g Florisil sorbent on top of 0.1-g samples, 12-ml n-hexane eluting at 1 ml/min, and a 10-ml extraction vessel]. Florisil sorbent was placed with the sample in the SFE vessel to provide a facile and effective clean-up approach. Mean recoveries of 78-121% with reproducibilities of 5-31% were obtained for the pesticides except for endosulfan II, endosulfan sulfate and endrin aldehyde. The simple and rapid method may be used to determine OCPs in CHMs routinely, and in fact, was used to analyze CHMs sold in Taiwan.

Chemical Phenomena↗
PubMed2001

PCBs and organochlorine pesticide residues in eggs of Audouin's gull (Larus audouinii) in the north-eastern Mediterranean.

Levels of eight PCB congeners (IUPAC 8, 20, 28, 52, 101, 118, 138, 180) and 13 organochlorine pesticides (alpha-BHC, beta-BHC, lindane (gamma-BHC), heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, 2,4'-DDT, 2,4'-DDD, 4,4'-DDT, 4,4'-DDD, 4,4'-DDE) were measured in unhatched Audouin gull eggs from Aegean Sea (northeastern Mediterranean) colonies in 1997 and 1998. Levels of more persistent congeners 138, 180 and in some colonies 118, predominated among PCBs. Between years significant differences were found in the levels of a variety of contaminants in the same regional colonies (Lipsos, Agathonisi, and Fourni) attributable to temporal changes in diet. Within years differences were limited (1997: PCB congeners 52, 118, 180, heptachlor and 4,4'-DDD; 1998: PCB congener 8 and heptachlor epoxide) which in combination with cluster analysis suggest a temporal rather than spatial pattern of pollution in the Aegean Sea. Maximum median levels of five PCB congeners, total PCBs and eight organochlorine pesticides were found in the Agathonisi and Fourni colonies suggesting an elevated nearby pollution probably from the polluted Menderez River. Levels of all contaminants were too low to have any adverse reproductive effects on the Audouin's gull of the Aegean colonies.

Animals↗
PubMedDate not supplied

Organochlorine compounds and aliphatic hydrocarbons in Pacific walrus blubber.

Blubber samples were collected from 8 male and 19 female Pacific walrus (Odobenus rosmarus divergens) taken during a 1991 joint USA/USSR cruise traveling widely through the Bering Sea. Dieldrin was found at a level similar to that reported 10 years earlier; oxychlordane was found at a slightly higher concentration than reported previously (Taylor et aL, 1989). Heptachlor epoxide was detected for the first time and found at a low concentration. An initial testing for alpha-, beta- and gamma-HCH detected concentrations similar to those in other Bering Sea pinnipeds. Mean summation of PCB was 0.45 microg g(-1) wet weight in males and 0.16 microg g(-1) in females; only one sample was > 1 microg g(-1). Traces of aliphatic hydrocarbons were detected in all sampled animals, only pristane (x = 0.48 microg g(-1)) was found in concentrations > 1 microg g(-1). Small sample sizes, a lack of samples from immature animals, and uniformly low concentrations of contaminants precluded meaningful analysis of age-related effects and regional differences.

Adipose Tissue↗
PubMed2002

Organochlorine pesticide residues in sediments and biota from the coastal area of Dar es Salaam city, Tanzania.

Sediment and biota samples were collected from Msimbazi and Kizinga rivers and from the coastal marine environment of Dar es Salaam during both dry and wet seasons. The samples were analyzed for various organochlorine pesticide residues using GC-ECD and GC-MS. Dieldrin, p,p'-DDT, p,p'-DDE, p,p'-DDD, o,p'-DDT and y-HCH were detected at significantly greater concentrations above the method detection limits. Recoveries of pesticide residues ranged 86.5-120% in sediments and 62-102% in biota. The average concentrations of total DDT in sediments for the two seasons were almost the same. Biota samples showed significant difference in levels of residues depending on mode of feeding and age of analyzed biota. p,p'-DDT to total DDT ratios in all matrices indicated recent use of DDT. The levels of residues in sediments suggest possible adverse effects to humans consuming biota that are directly exposed to the sediments. This effect, which is associated with bio-concentration of residues in the tissues of edible aquatic biota, should not affect wildlife. In spite of concern on the adverse effect to humans posed by pesticide residues in sediments, edible biota from the examined water bodies were found to be safe for human consumption.

Animals↗
PubMed2002

Toxic contaminants and their biological effects in coastal waters of Xiamen, China. I. Organic pollutants in mussel and fish tissues.

Organochlorines and organophosphates were measured in four fish species (Lateolabrax japonicus, Pagrasomus major, Miichthys miiuy and Epinephalus awoara) and the mussel Perna viridis collected from aquaculture cages in coastal waters of Xiamen, China. Polycyclic aromatic hydrocarbon (PAH) metabolites were also measured in fish bile. Sites in Xiamen coastal waters (the harbour, Maluan and Tongan) are compared with a "cleaner" reference site at Dongshan Island. DDT was found in livers of all fish sampled (May 1998, 1999 and December 1999) ranging from 0.15 to 2.2 microg/g WW, but levels in muscle tissue (<0.5 ng/g to 0.22 microg/g WW) were at least an order of magnitude lower in the harbour, and were not detectable (<0.5 ng/g) in Tongan samples. All other pesticides examined were not detected in fish or mussels, except for dieldrin in one liver sample (0.07 microg/g WW). Food of the caged fish, small fish and dried pellets, had very low (0.015-0.027 microg/g WW) or non-detectable levels of DDT, indicating significant bioaccumulation of contaminants in caged fish and/or other possible sources of uptake (water and sediments). DDT levels in fish varied with species. DDT contamination in fish livers and whole mussels varied significantly with location. Highest concentrations in fish occurred in the harbour, and less consistently so in Tongan. Dongshan and Maluan had comparatively low levels of DDT. Relatively low residues of DDT in both fish and mussels at Dongshan likely reflect lower levels of pesticide input at this reference site. However, the low levels of DDT contamination in fish tissues from Maluan were unexpected in view of the close proximity of the harbour and possibly reflect the removal of particulate-bound contaminants by the intensive bivalve culture there. Consistently high proportions of DDT in the form of the parent compound (p,p'-DDT: fish 30-45%; mussels 40-65%) from all sites suggest recent releases of this chemical to the environment. Levels of two main groups of PAH metabolites (naphthalene and phenanthrene) in fish bile suggest a different environmental distribution pattern than that of pesticides, in that Dongshan fish appear to be no less exposed to hydrocarbons than those from Xiamen coastal waters.

Animals↗
PubMed2002

Organochlorine pesticides and PCB residues in sediments of Alexandria Harbour, Egypt.

Persistent organochlorine compound concentrations were determined for 23 surface sediment samples collected from Alexandria Harbor, Egypt. Total PCB concentrations ranged from 0.9 to 1210 ng/g with four to seven Cl-substituted biphenyls being the most prevalent PCBs congeners. Different PCB congener distribution patterns were observed, probably reflecting different inputs and attenuation at various locations. Total DDT concentrations varied from <0.25 ng/g to 885 ng/g. The ratios of DDTs (2,4'- and 4,4'-DDT)/total DDTs (DDTs plus metabolites) in sediment samples from certain sites were 0.86 or higher, indicating little attenuation or recent input of DDT. Total chlordane (the sum of heptachlor and its epoxide, oxy-, gamma- and alpha-chlordane and cis + trans-nonachlor) ranged from <0.25 to 44 ng/g with the highest concentration found in the Arsenal Basin. The geographic distributions of PCBs, total DDTs and total chlordane were similar. Chlorinated benzenes (CBs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin, endrin, chloropyrifos, endosulfan, mirex and pentachloroanisole were below detection limits or detected at low concentrations in most of the samples. Sites that were contaminated with high concentrations of organochlorine compounds were associated with dense population and low energy environment. The contamination levels of PCBs, total DDTs and total chlordane were in high range compared to other locations worldwide.

Egypt↗
PubMed1977

Pesticide induced DNA damage and its repair in cultured human cells.

The effects of pesticides on the induction of unscheduled DNA synthesis in SV-40 transformed human cells (VA-4) in culture with and without metabolic activation by liver microsomes was studied. Results showed that ten of the thirteen compounds examined either directly or upon metabolic activation induced unscheduled DNA synthesis in the human cell system used. The DNA repair kinetics and size of the repaired regions resulting from treatment with four of the chemicals (Carbaryl, Chlordane, Dieldrin and 2.4-D Fluid) were studied by 313 nm photolysis of repaired regions containing bromodeoxyuridine (BUdR). The size of the repaired regions differed between compounds but could generally be classified as either of the X-ray (short) or UV-type (long).

Cell Line↗
PubMed2001

Monitoring of organochlorine and organophosphorus pesticides in the water of the Reconquista River (Buenos Aires, Argentina).

The Reconquista river is a typical example of the adverse impact of human activity on a watercourse. Approximately 10% of the population of the country is settled on its basin and it receives wastewater discharges from residences and industries. This paper describes the results of the first systematic data for measurement of pesticides in surface water of the river, based on a monthly monitoring program over two-year span. The analyses were performed, in three sampling stations (S1, S2 and S3), along 46 km of its course, following the AOAC methods. Screening included the following pesticides: (a) Organochlorines: alpha, beta and gamma HCH; heptachlor, heptachlor epoxide; aldrin; endrin; dieldrin; op' and pp' DDT; op' and pp' DDE; alpha and gamma chlordane and endosulphan II; (b) Organophosphates: ethyl and methyl parathion; chlorpyrifos and fenitrothion. From the 60 samples analyzed, 35% contained organochlorine pesticides in a concentration higher than the detection limit. Organophosphates were found in no case. Throughout the studied period, DDT and its metabolite DDE were only found in S1 and gamma chlordane in S3; heptachlor was present in 50% of the samples of S2 and in 35% of S3, while HCH isomers were detected in 38% of S2 and 45% of S3 samples. Neither temporal nor spatial trends were found. There was not a relationship between the time of samplings and the fumigation season for farming purposes. At all locations, pesticides levels were found to be between 40 and 400 times higher than the legal limits established for protection of aquatic life.

Agriculture↗
PubMed2003

Comparison of nutrient and contaminant fluxes in two areas with different hydrological regimes (Empordà Wetlands, NE Spain).

Nutrient (N and P), heavy metal (Ni, Cd, Cr, Cu and Pb) and pesticide (DDT, DDD, DDE, lindane, aldrin, endrin, dieldrin, permethrin, atrazine and simazine) concentrations in water and sediment were analysed in the Empordà Wetlands, a Mediterranean wetland area in NE Spain. Mean nutrient and contaminant concentrations and input and output loads via tributaries were compared in two marshes with different water turnover: a freshwater marsh (FWM), with a high water turnover rate due to continuous surface water inputs and outputs, and a brackish water marsh (BWM), with lower turnover and no continuous surface output, where water remains confined during dry periods. Mean concentrations of most heavy metals exceeded the maximum permissible concentration (MPC) in BWM, whilst only some pesticides reached MPC in FWM. The confined waters of BWM showed higher sensitivity to contaminant input loadings than FWM due to the lack of continuous water outputs. Non-point source pollution inputs during runoff (mainly in FWM) and concentration during confinement (mainly in BWM) showed as the main environmental problems related to nutrients and contaminants in these ecosystems. Thus, the importance of confinement and its effect on pollutant concentrations must be borne in mind to achieve correct management of Mediterranean wetlands.

Ecosystem↗