Monitoring Of Organic Pollutants Research Articles

Scientific Insights into the Quantum Dots (QDs)-Based Electrochemical Sensors for State-of-the-Art Applications.

Size-dependent optical and electronic properties are unique characteristics of quantum dots (QDs). A significant advantage is the quantum confinement effect that allows their precise tuning to achieve required characteristics and behavior for the targeted applications. Regarding the aforementioned factors, QDs-based sensors have exhibited dramatic potential for the diverse and advanced applications. For example, QDs-based devices have been potentially utilized for bioimaging, drug delivery, cancer therapy, and environmental remediation. In recent years, use of QDs-based electrochemical sensors have been further extended in other areas like gas sensing, metal ion detection, monitoring of organic pollutants, and detection of radioactive isotopes. Objective of this study is to rationalize the QDs-based electrochemical sensors for state-of-the-art applications. This review article comprehensively illustrates the importance of aforementioned devices along with sources from which QDs devices have been formulated and fabricated. Other distinct features of QDs devices are associated with their extremely high active surfaces, inherent ability of reproducibility, sensitivity, and selectivity for the targeted analyte detection. In this review, major categories of QD materials along with justification of their key roles in electrochemical devices have been demonstrated and discussed. All categories have been evaluated with special emphasis on the advantages and drawbacks/challenges associated with QD materials. However, in the interests of readers and researchers, recent improvements also have been included and discussed. On the evaluation, it has been concluded that despite significant challenges, QDs-based electrochemical sensors exhibit excellent performances for state-of-the-art and targeted applications.

Profiling organic pollutants in environmental water by dansylation-based non-targeted liquid chromatography-high resolution mass spectrometry analysis

Monitoring organic pollutants in rainwater is important to understand relations between air pollutants and water safety. Non-targeted liquid chromatography–mass spectrometry (LC–MS) is a powerful tool but because of big differences of pollutants in polarity, ionization efficiency, and low concentrations, it is challenging to detect all pollutants in a single analysis. Chemical derivatization is a widely adapted strategy to fractionate complex samples with enhanced sensitivity and selectivity. Herein, we propose the usage of dansylation as a chemical derivatization method to improve both LC retention and MS ionization of organic pollutants containing amine, hydroxyl, and carboxyl for non-targeted LC–MS analysis. We first evaluated the labeling coverage of dansylation to organic pollutants in water matrix. Using dansyl chloride (DnsCl) and dansyl hydrazine (DnsHz) to label 100 amine- and hydroxyl-containing compounds and 100 carboxyl compounds, respectively, we found DnsCl and DnsHz had over 60% labeling coverage for 8 categories of compounds. Then dansylation was applied to label the rainwater, source water, disinfected rainwater, and drinking water samples. To facilitate the annotation of dansylated compounds, we also established a web-based tool termed DansylFinder. Using DansylFinder, 3889, 5813, 6077, and 4050 tentative annotations were found in rainwater, source water, disinfected rainwater, and drinking water samples by dansylation-based non-targeted LC-HRMS analysis. Four hundred fifty four were persistently detected in all water samples, suggesting significant organic overlaps of the four water samples. In addition, two degradation pathways reported in drinking water disinfection process were also detected in disinfected rainwater, suggesting rainwater is a potential path for air pollutants to infiltrate drinking water system.

Health Risk Assessment from Exposure to Ambient Volatile Organic Compounds (VOCs) at a Truck Tire Factory in the Yangtze River Delta, China

Occupational health risk assessments of exposure to VOCs still need to be extensively studied to improve the safety standards in the industry. Based on the monitoring of organic pollutants at various workstations in a truck tire factory in Jiangsu Province, both semi-quantitative and quantitative health risk assessment methods were employed to assess health risk levels. The findings indicated that VOCs were categorized into five classes, which included alkanes, aromatics, halocarbons, carbon disulfide, and oxygenated volatile organic compounds (OVOCs). The highest concentration of total volatile organic compounds (TVOCs) was found in shaping workshop; alkanes were the most abundant class (74.2%), followed by aromatics (24.02%) and OVOCs (1.96%). Although the results of the semi-quantitative risk assessment showed that most of the organic compounds had low R values, various kinds of VOCs were detected; particularly, many harmful organic compounds (such as toluene, ethyl benzene) were detected in all the sampling sites. The quantitative risk in the calendering and vulcanizing workshop exceeded the acceptable level; both the carcinogenic risk of ethylbenzene in the tire-strip storage room, and trichloroethylene and perchloroethylene in the calendering workshop were unacceptable. Thus, the calendering and vulcanizing processes in rubber tire manufacturing should be priority-controlled processes.

An electrochemical sensor based on a pencil graphite electrode modified with poly-riboflavin for 4-nitrophenol quantification

It is essential to develop a simple and disposable electrochemical sensor for monitoring organic pollutants in water systems. This work aims in the quantification of hazardous water pollutant 4-Nitrophenol (4-NP) by electropolymerizing vitamin B complex (Vitamin B2/Riboflavin) over pencil graphite electrode (PGE). By differential pulse voltametric technique, the anodic peak current increased appreciably for 4-NP oxidation on poly-riboflavin modified pencil graphite electrode (PRB/PGE) as compared to bare PGE. The adapted sensor was characterized using scanning electron microscopy (SEM), infrared spectrometry (IR), energy dispersive X-ray analysis (EDX) and electrochemical impedance spectroscopy (EIS). The increased electroactive surface area and decreased electron transfer resistance was achieved by electropolymerisation of the electrode. A well-defined anodic peak of 4-NP was observed on the adapted electrode at a potential of +0.864 V in phosphate buffer solution of pH 7.2. Factors affecting the current response were optimized. Scan rate and pH analysis were used to study the fabricated electrode and thereby determining transfer electron and proton number. The sensor spectacled a linearity of 5.0 μM–700.0 μM with lower detection of limit (LOD) of 1.78 μM and limit of quantification (LOQ) of 5.94 μM. By using a simple single-step fabrication method, the PRB/PGEs exhibit high stability, reproducibility and repeatability making them an ideal tool to detect 4-NP in real water samples. The developed disposable sensor exhibited a recovery between 97-103%. Hence it is found to be a favorable tool for the electroanalysis of the analyte with high reliability.

Improved water quality monitoring indicators may increase carbon storage in the oceans

Indicators related to organic matter are important when assessing aquatic environment quality. The chemical oxygen demand (COD) is widely used as a water quality reference. However, oxidizing agents used to determine the COD can oxidize refractory organic matter that is not pollutant and can persist in the ocean for thousands of years. This means the COD can misrepresent the water quality. The actual water quality can be indicated better by the biochemical oxygen demand (BOD) than the COD, but determining the BOD is time-consuming and gives variable results. In this study, the optical properties of dissolved organic matter in water samples from the Chinese coast that had been incubated for a long time or directly oxidized using COD oxidant were analyzed. The results indicated that the oxidizing agent rapidly oxidized 22.93% ± 4.96% of refractory dissolved organic matter (RDOM) that was resistant to microbial degradation, implying that RDOM made a marked contribution to the COD. Meanwhile, size-fractional fluorescence spectroscopy and COD measurements indicated that the COD of the >0.7 μm fraction and the fluorescence intensity of the protein-like component significantly positively correlated with the BOD of the bulk sample. This indicated that, for monitoring organic pollutants in coastal waters, the COD of the >0.7 μm fraction could be used as a proxy for the standard COD and that the fluorescence intensity of the protein-like component could be used as a convenient proxy for the BOD. The method can help retain recalcitrant organic matter in seawater to act as a carbon sink.

Monitoring of organic pollutants in Choromytilus meridionalis and Mytilus galloprovincialis from aquaculture facilities in Saldanha Bay, South Africa

Abstract Persistent organic pollutants are lipophilic contaminants which can accumulate in marine food chains, causing health issues for human consumers. Farmed C. meridionalis and M. galloprovincialis were collected and analysed for POPs, extracted using QuEChERS method and analysed via GC-MS/MS. Detected OCPs (trans-permethrin > cis-permethrin > dieldrin > chlordane > chloro-benzilate > endosulfan > nonachlor > DDD) were highest contributors to POP contamination (average: 0.7 – 48 ng/g dry weight), followed by PAHs (flourene > pyrene > fluoranthene > benzo(a)pyrene > benz(a)anthracene; average: 1 – 13.4 ng/g d.w.), and PCBs (180 > 149 > 28 > 110 > 153 > 52 > 18 > 44 > 118 > 138; average: 0.3 – 3.2 ng/g d.w). Temporal differences were detected in both species for cis- and trans-permethrin, and PCBs 18, 118 and 149, with seasonal changes linked gametogenic cycle (fat) of mussels. All POP contaminants were below maximum limits of international regulations.

Correlations between hair and tissue mercury concentrations in Icelandic arctic foxes (Vulpes lagopus)

Monitoring organic pollutants in wildlife is a common approach to evaluate environmental health, chemical exposure and to make hazard assessments. However, pollutant concentrations measured from different tissue types among studies impede direct comparisons of levels and toxicity benchmarks among species and regions. For example, mercury (Hg) is a metal of both natural and anthropogenic origin which poses health risks for marine and arctic biota in particular. Although hair is recognized as the least invasive sample type for Hg exposure measurement in wildlife, measurements in previous studies have used different tissues among individuals and species. This lack of tissue type consistency hinders cross study comparisons. Therefore to systematically evaluate the use of hair in ecotoxicological studies, total mercury (THg) concentrations measured from hair were compared to values obtained from liver and kidney in 35 Icelandic arctic foxes (Vulpes lagopus). THg concentrations varied considerably among tissues with hair and kidney levels generally lower than in liver. Nevertheless, significant correlations among tissue types were observed. THg values in hair were predictive for liver (R2=0.61) and kidney THg levels (R2=0.51) and liver values were a good predictor of THg in kidney (R2=0.77). We provide further evidence that non-invasively collected hair samples reflect the THg levels of internal tissues. We present equations derived from multiple linear regression models that can be used to relate THg levels among tissue types in order to extrapolate THg values from hair to soft tissues. Using these equations, we compare the results of previous studies monitoring THg levels in different tissues of arctic foxes from various regions of the Arctic. Our findings support that hair is a suitable sample matrix for ecotoxicological studies of arctic predators and may be applied in both wildlife welfare and conservation contexts for arctic vulpine species.

Significance of Anthropogenic Factors to Freely Dissolved Polycyclic Aromatic Hydrocarbons in Freshwater of China.

Assessment of surface water pollution by organic pollutants is a top priority in many parts of the world, as it provides critical information for implementing effective measures to ensure drinking water safety. This is particularly important in China, where insufficient data of national scale have been acquired on the occurrence of any organic pollutants in the country's water bodies. To fill the knowledge gap, we employed passive samplers to survey polycyclic aromatic hydrocarbons (PAHs) in 42 freshwaters throughout the country. The dissolved Σ24PAH concentrations ranged from 0.28 to 538 ng L-1, with the highest and lowest values obtained in Southern Lake in Wuhan and in the Nam Co Lake in Tibet, respectively. Average Σ24PAH concentrations in West, Central, and East China correlated well with the population densities in these regions. The composition profiles of PAHs showed a mixed PAH source of coal combustion, fossil fuel combustion, and oil spills. In addition, all dissolved PAH concentrations were below the water guidelines developed by the U.S. Environmental Protection Agency, the European Union, and the Canadian government, except for anthracene in Southern Lake. Our results also demonstrated the feasibility of establishing a global network of monitoring organic pollutants in the aquatic environment with passive sampling techniques.

European demonstration program on the effect-based and chemical identification and monitoring of organic pollutants in European surface waters

Growing concern about the adverse environmental and human health effects of a wide range of micropollutants requires the development of novel tools and approaches to enable holistic monitoring of their occurrence, fate and effects in the aquatic environment. A European-wide demonstration program (EDP) for effect-based monitoring of micropollutants in surface waters was carried out within the Marie Curie Initial Training Network EDA-EMERGE. The main objectives of the EDP were to apply a simplified protocol for effect-directed analysis, to link biological effects to target compounds and to estimate their risk to aquatic biota. Onsite large volume solid phase extraction of 50 L of surface water was performed at 18 sampling sites in four European river basins. Extracts were subjected to effect-based analysis (toxicity to algae, fish embryo toxicity, neurotoxicity, (anti-)estrogenicity, (anti-)androgenicity, glucocorticoid activity and thyroid activity), to target analysis (151 organic micropollutants) and to nontarget screening. The most pronounced effects were estrogenicity, toxicity to algae and fish embryo toxicity. In most bioassays, major portions of the observed effects could not be explained by target compounds, especially in case of androgenicity, glucocorticoid activity and fish embryo toxicity. Estrone and nonylphenoxyacetic acid were identified as the strongest contributors to estrogenicity, while herbicides, with a minor contribution from other micropollutants, were linked to the observed toxicity to algae. Fipronil and nonylphenol were partially responsible for the fish embryo toxicity. Within the EDP, 21 target compounds were prioritized on the basis of their frequency and extent of exceedance of predicted no effect concentrations. The EDP priority list included 6 compounds, which are already addressed by European legislation, and 15 micropollutants that may be important for future monitoring of surface waters. The study presents a novel simplified protocol for effect-based monitoring and draws a comprehensive picture of the surface water status across Europe.

Passive Sampling of Polycyclic Aromatic Hydrocarbons in Johor Strait by Sol–gel Polydimethylsiloxane

Passive sampling technique is an alternative technique in the monitoring of organic pollutants in aqueous environment. This technique is able to overcome several drawbacks of the conventional grab sampling technique. In this study, passive sampler consists of glass tubes coated with sol–gel polydimethylsiloxane (PDMS) were fabricated in the laboratory. The passive samplers were used to study the level and distribution of 15 polycyclic aromatic hydrocarbons (PAHs) in Johor Strait. Performance of the passive sampler was tested in the laboratory with an exposure system that has similar flow rate, temperature and water salinity with Johor Strait. Then, the passive sampler was deployed to five sampling stations located in Johor Strait for 7 and 30 days to accumulate PAHs in seawater. High performance liquid chromatography with fluorescence detector was used to analyze PAHs in the samples. All PAHs spiked in the exposure system were found to accumulate in the PDMS coating. Mass of 15 PAHs extracted from the passive sampler after deployment to Johor Strait was in the range of 0.372–1.131 ng/PDMS glass tube. Findings obtained from passive sampling method and seawater analysis were comparable. Passive sampling technique is low cost, simple and less solvent consumption.

Effect of Ambient Temperature on PUF Passive Samplers and PAHs Distribution in Puerto Rico

Passive sampling for the monitoring of organic pollutants (PAHs, PCBs, PBDEs) in ambient air has received increased attention in the last two decades. However, the accuracy of the concentration of organics obtained with passive samplers under varying environmental conditions is a subject of controversy. In this study, effect of ambient temperature on passive samplers was evaluated by using three different sampler configurations. Additionally, passive samplers with polyurethane disks (PUF) were applied throughout the Island for the determination of the airborne concentration of polycyclic aromatic hydrocarbons (PAHs). The passive samplers were deployed in seven municipalities for three-month periods in two different sampling campaigns, representing hurricane and non-hurricane seasons. Here we present preliminary results obtained from those sampling campaigns. The total concentrations of 15 PAHs varied from 3.1 to 19.6 and from 5.5 to 38.5 ng/m3 for hurricane and non-hurricane seasons, respectively. Hurricane and non-hurricane season concentrations of PAH were significantly different for the samples taken in the northern municipalities of the Island. However, there was no significant difference in PAH concentrations between the hurricane and non-hurricane seasons for the southern sites. Increased rainfall and high-relative humidity during the hurricane season had an influence on the concentrations of PAHs derived by the passive PUF sampler.

Determining Organic Pollutants in Automotive Industry Sludge

In Brazil, the policy for disposing industrial sludge is changing from an emphasis on using controlled landfills to other treatment or co-processing methods; however, the monitoring of organic pollutants is not mandatory. The present study evaluated two general screening methods for organic pollutants in sludge generated in an automotive industrial complex in southern Brazil. The screening was performed using Soxhlet and sonication extractions and Gas Chromatograph coupled with Quadrupole Mass Spectrometry (GC/qMS). It was concluded that both techniques were effective and that most of the compounds identified were alkanes, phenols and esters. Important pollutants were detected in the sludge, which confirms the necessity of monitoring this type of residue.

Persistent Organic Pollutants in Muscle and Feather of Ten Avian Species from Māzandarān Province of Iran, on the Coast of the Caspian Sea

Feather and muscle of 10 avian species (n=46), were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Muscle contained significantly higher PCB and OCP than liver and feather. Mean muscle and feather PCB was 408.5±134.5 and 32±4.5ng/g wet weight. Highly chlorinated PCBs were found in muscle and liver while feather had PCBs with less chlorination. Gulls had highest levels of both pollutants. Gull feather PCB and OCP were strongly correlated with their levels in the liver and muscle tissues (0.6<r<0.9, p<0.01). Analysis of gull feather can be used as a non-invasive method for monitoring organic pollutants.

Electrospun Nanofibers Sorbents for Pre-Concentration of 1,1-dichloro-2,2 bis-(4-chlorophenyl)ethylene with Subsequent Desorption by Pressurized Hot Water Extraction

Electrospun polystyrene (PS) nanofibers (130–500 nm) incorporating a potassium salt of imidazole-1-carbodithioate were evaluated as potential sorbents for the pre-concentration of a model organochlorine pesticide; 1,1-dichloro-2,2bis-(4-chlorophenyl)ethylene (DDE). The efficiencies of DDE (0.25–1.0 μg L−1) adsorption by the nanofiber sorbent followed by desorption employing pressurized hot water extraction (PHWE) were investigated and monitored using gas chromatography with electron capture detection (GC-ECD). Parameters such as time, temperature and pressure of extraction, sample volume, DDE concentration and sorbent mass were optimized. The maximum adsorption of DDE (0.50 μg L−1) on electrospun PS and carbodithioate incorporated PS nanofibers was at 43.7 and 94.6%, respectively, in 20 min. Incorporation of carbodithiote doubled the adsorption efficiency of PS and achieved LOD of 0.000234 μg L−1 for DDE. The optimal DDE desorption on the PHWE system was 93.8% in 10 min. It would seem that the use of electrospun nanofibers as sorbent material with subsequent desorption by PHWE has great potential and thus warrants further investigations. This approach as it uses water as an extraction solvent for an organochlorine pesticide provides an opportunity to eliminate organic solvents, especially for procedures aimed at monitoring organic pollutants in the environment.

Polycyclic aromatic hydrocarbons in air and snow from Fairbanks, Alaska

There has been increasing interest regarding the use of passive air samplers as tools for monitoring organic pollutants in the atmosphere. In this study we report results obtained from passive air samplers that were deployed in both indoor and outdoor environments across the City of Fairbanks, AK, for the polycyclic aromatic hydrocarbons (PAHs) during winter 2009. It is demonstrated that the passive air samplers provide reliable data for the gas-phase PAHs. Results for particulate-phase isomers, however, are more variable and thus likely to be less reliable. For instance, the use of passive air samplers in indoor environments does not appear effective for distinguishing between homes with and without wood stoves, largely due to discrepancies associated with measuring particulatephase PAHs. Consequently, it is suggested that the passive air samplers should not be used for assessing indoor exposures to particulate-bound pollutants. Nevertheless, air concentrations obtained from active air samplers indicate that PAHs in air are dominated by the gas-phase isomers, resulting in good agreement between the active and passive air samplers for outdoor air. The average passive indoor air concentrations for ΣPAH20 are observed to be slightly higher than passive outdoor air concentrations, at 55 and 26ng m-3 respectively. Concentrations in outdoor air for the City of Fairbanks are reported to be an order of magnitude lower during 2009 than during the winter of 1976/77, when they were last reported. Snow data for the PAHs are reported as a complement to the air concentration data, showing similar isomer patterns between air and undisturbed snowpack samples. Snow samples collected from snow dump collection sites are reported to be 25 times greater than nearby undisturbed snow, and are dominated by the particulate-phase PAHs. Recommendations for future monitoring of snowmelt from the snow dump collection sites are suggested.

Advances in immunochemical technologies for analysis of organic pollutants in the environment

Due to the increasing number of organic pollutants, implementation of European Union Directives calls for rapid, reliable, cost-effective, and smart technologies for water analysis. Immunoaffinity of an antibody to an antigen has been used for the development of a wide variety of analytical techniques applicable in environmental monitoring. This article reflects recent advances in development and application of immunochemical techniques for environmental analysis and monitoring of organic pollutants. We briefly summarize several examples. We especially emphasize current trends and future perspectives in immunosensor configurations, including nanotechnology, miniaturization, and multi-sensor array development, and we discuss the advantages and the limitations of these.

Determination of Ecological State of Small Rivers in the City Area of Kiev in Accordance with the European Water Framework Directive (WFD)

The introduction of the European Water Framework Directive (WFD) in Ukraine is under discussion during few years and that has led to an increased interest in such approach. This article shows ways of practical performance of three key methods that can be applied to assess the ecological status of small rivers. There are the classification of water quality (here: the aspect of organic load), river habitat assessments and monitoring of organic pollutants. The approach mentioned above was applied to assess the ecological state of small rivers in the territory of the city of Kiev. For the water quality classification, the saprobic indices have been related to reference conditions for sandy lowland rivers. The classification of results of the river habitat assessments was also based on a method usually applied in Germany. To detect organochlorine compounds, the use of the AOC method for first screenings is recommended here.

MICREDOX ®—development of a ferricyanide-mediated rapid biochemical oxygen demand method using an immobilised Proteus vulgaris biocomponent

Biochemical oxygen demand (BOD) is an international regulatory environmental index for monitoring organic pollutants in wastewater and the current legislated standard test for BOD monitoring requires 5 days to complete (BOD 5 test). We are developing a rapid microbial technique, MICREDOX ®, for measuring BOD by eliminating oxygen and, instead, quantifying an equivalent biochemical co-substrate demand, the co-substrate being a redox mediator. Elevated concentrations of Proteus vulgaris, either as free cells or immobilised in Lentikat ® disks, were incubated with an excess of redox mediator (potassium hexacyanoferrate(III)) and organic substrate for 1 h at 37 °C without oxygen. The addition of substrate increased the catabolic activity of the microorganisms and the accumulation of reduced mediator, which was subsequently re-oxidised at a working electrode generating a current quantifiable by a coulometric transducer. The recorded currents were converted to their BOD 5 equivalent with the only assumption being a fixed conversion of substrate and known stoichiometry. Measurements are reported both for the BOD 5 calibration standard solution (150 mg l −1 glucose, 150 mg l −1 glutamic acid) and for filtered effluent sampled from a wastewater treatment plant. The inclusion of a highly soluble mediator in place of oxygen facilitated a high ferricyanide concentration in the incubation, which in turn permitted increased concentrations of microorganisms to be used. This substantially reduced the incubation time, from 5 days to 1 h, for the biological oxidation of substrates equivalent to those observed using the standard BOD 5 test. Stoichiometric conversion efficiencies for the oxidation of the standard substrate by P. vulgaris were typically 60% for free cells and 35–50% for immobilised cells.

Monitoring of organic pollutants in coastal waters of the Gulf of Gdańsk, Southern Baltic

This paper presents an overview of changes in organic pollution of coastal waters of the Gulf of Gdańsk (Baltic Sea). Toxic pollutants including volatile organic compounds (VOC), volatile organohalogen compounds (VOX), chlorophenols, phenoxyacids, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were determined in seawater from the Gulf of Gdańsk coastal waters in the period 1996–2001. In the case of the Gulf of Gdańsk, non-conservative behaviour of VOC was observed due to random temporal and spatial of inputs along the Vistula estuary and to the dilution of VOC-enriched river water with seawater. The concentrations of VOX in seawater decreased throughout the period and the concentrations of VOX were in the range of few ng dm −3 up to 250 ng dm −3, similar to estuaries elsewhere. The average concentrations of chlorophenols and phenoxyacids were between 0.1 and 6.0 and 0.05 and 2.2 μg dm −3, respectively. However, remarkably high concentrations of 2,4-dichlorophenol (6 μg dm −3) were obtained in samples collected from the Vistula River. Generally concentrations of PCBs did not exceed few ng dm −3 with the exception of 1999, when all samples exhibited elevated concentrations of PCBs. In addition, higher concentrations of PCBs in the open sea compared to river waters suggested localised inputs. Due to the ability of most organic pollutants to bioaccumulate and biomagnify, especially the persistent organic pollutants, continued monitoring is of crucial importance for the health of marine life in the Gulf of Gdańsk.

Organic contamination in the greenhouse soils from Beijing suburbs, China.

Selected persistent organic pollutants including HCHs, DDTs and PAHs together with PAEs were determined in the greenhouse soils from Beijing suburbs. The total concentrations were 11.64-29.80 ng g(-1) for HCHs, 18.04-101.33 ng g(-1) for DDTs, 1.34-3.15 microg g(-1) for PAEs and 1.92-7.84 microg g(-1) for PAHs, respectively. Predominance of beta-HCH in all samples was obviously observed, suggesting a lack of new HCHs sources. High concentrations of DDE and DDD in comparison to their parents in the samples indicated that most of the DDT had been transformed into its metabolites. The contamination of PAHs was relatively serious and the most abundant compounds were 4-, 5- and 6-ring unsubstituted PAHs. The profiles reflect the important effect of traffic on the PAHs remaining in greenhouse soils. Three phthalate esters (DIBP, DnBP and DEHP) accounted for more than 97% of the phthalates studied. Analysis of n-alkanes was also performed in order to trace the natural or anthropogenic sources of hydrocarbons. Characterization and identification of these compounds in greenhouse soil may help in development of strategies to be used in monitoring organic pollutants in this region.