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1.
To collect a large data set regarding the occurrence of organic substances in sediment, this study presents the examination of 20 micropollutants, as a national survey. The list of target compounds contains two alkylphenols, three polycyclic aromatic hydrocarbons (PAHs) not commonly included in monitoring programmes, six pesticides or metabolites, five pharmaceutical compounds, two hormones, one UV filter and bisphenol A. The selective and sensitive analytical methods, based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) or gas chromatography-time-of-flight mass spectrometry (GC-ToF-MS), allow the quantification at limits comprised between 0.5 and 23 ng/g, depending on the compound. The paper summarizes the analytical results from 154 sampling points. Of the 20 target compounds, 9 were determined at least once, and the sediments contained a maximum of 7 substances. The most frequently detected were PAHs (frequency, 77 %; max., 1,400 ng/g). The pharmaceutical compounds, hormones and pesticides were rarely detected in the samples; the most frequently detected was carbamazepine (frequency, 6 %; max., 31 ng/g). In some cases, the levels of PAHs and bisphenol A exceed the predicted no-effect concentration (PNEC) values.  相似文献   

2.
We investigated contamination by endocrine-disrupting chemicals in drinking water from 35 major Italian cities and five popular Italian brands of bottled mineral water. The quality of Italian drinking water was assessed by combing chemical analysis with bioassay to quantify specific estrogenic contaminants and to characterize the actual biological effect of the mixture of chemicals present in drinking water including the contribution of not targeted compounds. The selected contaminants were natural and synthetic steroid estrogens, alkylphenols and bisphenol A, linuron, triazine herbicides, and their metabolites. A specific analytical method was developed based on solid phase extraction of 1 L of water and concentration to 100 μL for quantification by electrospray ionization liquid chromatography tandem mass spectrometry, achieving quantification limits of 0.05–0.36 ng/L for herbicides and 0.64–7.70 ng/L for steroids and phenols. No steroid estrogens were detected in any of the samples, while bisphenol A and nonylphenols were detected in the ranges of 0.82–102.00 and 10.30–84.00 ng/L respectively. Herbicides and their degradation products, when present, were found from slightly above the quantification limits up to 49.91 ng/L, mainly from cities in northern Italy. Chemical analyses were complemented by the performance of a bioassay for the determination of the estrogenic activity in the extracts based on the transactivation of estrogen receptor α-transfected reporter HeLa-ERE-Luciferase-Neomycin cell line. Activity was generally low with maximum estrogenicity of 13.6 pg/L estradiol equivalents.  相似文献   

3.
According to its high production and value, Akkar is considered as the second agricultural region in Lebanon. Groundwater constitutes the principal source of water in Akkar including drinking water of local inhabitants in Akkar. As such, the contamination of groundwater by organic pollutants can impact directly the population health. In this study, we evaluated the contamination status of groundwater in this region. Three classes of pesticides including 19 organochlorine (OC) pesticides, 8 organophosphorus (OP) pesticides, and 6 organonitrogen (ON) pesticides were monitored in 15 groundwater samples collected from different villages on the Akkar plain. Samples were extracted by using solid phase extraction (SPE) and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The results showed high contamination of Akkar groundwater by OCs with levels that can reach 58.9 μg/L. They were detected in the majority of the sample and represent 95–100% of ∑pesticides. Our results showed the recent use of these molecules with an average level of 0.3 and 0.39 μg/L for ∑HCHs and DDTs, respectively. Their concentrations were higher than those observed in the same region in 2014 and other regions elsewhere. OPs were also detected at high levels and among them, methylparathion was the predominant OP detected (44.6 μg/L). For ONs, lower levels were measured in all samples with a mean value of 5.6 μg/L. As a conclusion of this work, groundwater on the plain of Akkar was remarkably contaminated by the studied pesticides; indefinitely, more efforts should be taken to manage the pesticide use in this region, assess, and reduce their effects on human health. In the future, the application of organic farming can be a great solution to the groundwater contamination problem.  相似文献   

4.
17β-Estradiol (E2) and 17α-ethinyl estradiol (EE2), which are environmental estrogens, have been determined with LC-MS in freshwater. Their sensitive analysis needs derivatization and therefore is very hard to achieve in multiresidue screening. We analyzed samples from all the large and some small rivers (River Danube, Drava, Mur, Sava, Tisza, and Zala) of the Carpathian Basin and from Lake Balaton. Freshwater was extracted on solid phase and derivatized using dansyl chloride. Separation was performed on a Kinetex XB-C18 column. Detection was achieved with a benchtop orbitrap mass spectrometer using targeted MS analysis for quantification. Limits of quantification were 0.05 ng/L (MS1) and 0.1 ng/L (MS/MS) for E2, and 0.001 ng/L (MS1) and 0.2 ng/L (MS/MS) for EE2. River samples contained n.d.–5.2 ng/L E2 and n.d.–0.68 ng/L EE2. Average levels of E2 and EE2 were 0.61 and 0.084 ng/L, respectively, in rivers, water courses, and Lake Balaton together, but not counting city canal water. EE2 was less abundant, but it was still present in almost all of the samples. In beach water samples from Lake Balaton, we measured 0.076–0.233 E2 and n.d.–0.133 EE2. A relative high amount of EE2 was found in river Zala (0.68 ng/L) and in Hévíz-Páhoki canal (0.52 ng/L), which are both in the catchment area of Lake Balaton (Hungary).  相似文献   

5.
The synthetic growth-promoting hormones trenbolone and melengestrol acetate have been detected in the environment near beef cattle feedlots and are reportedly transported via wind-borne particulate matter. Therefore, movement of synthetic hormones from beef cattle feedlots to water bodies via particulate matter is possible. Our objective was to evaluate potential effects of 17α-trenbolone (17α-TB), melengestrol acetate (MGA), and combinations of both on growth, development, and survival of Xenopus laevis larvae. On post-hatch day 2 (stage 33/34), X. laevis larvae were exposed to three nominal concentrations of 17α-TB (10, 100, and 500 ng/L), MGA (1, 10, and 100 ng/L), a combination of both (1/10, 10/100, and 100/500 ng/L MGA/17α-TB), frog embryo teratogenesis assay-Xenopus medium, or a solvent control. Significant increases in all X. laevis growth metrics were observed among larvae in the 1 ng/L MGA?+?10 ng/L 17α-TB and 10 ng/L MGA?+?100 ng/L 17α-TB treatments. Stage of development was increased among larvae in the 1 ng/L MGA?+?10 ng/L 17α-TB treatment group and significantly decreased among those in the 500 ng/L 17α-TB treatment. Total body mass and snout–vent length of X. laevis larvae were significantly reduced in the 100 ng/L MGA and 100 ng/L MGA?+?500 ng/L 17α-TB treatment groups. Larvae exposed to 500 ng/L 17α-TB had decreased total body mass, snout–vent length, and total length. In general, growth measurements decreased with increasing concentration of MGA, 17α-TB, or a combination of both. Survival among all treatments was not significantly different from controls. Amphibians exposed to MGA and 17α-TB in the environment may experience alterations in growth and development.  相似文献   

6.
Fifty samples of finished drinking waters (FDWs) from Spain covering 12 million inhabitants were tested for 53 pharmaceuticals pertaining to 12 different Anatomical Therapeutic Chemical (ATC) classification system codes. The studied compounds are a combination of most commonly consumed pharmaceuticals with other barely reported in the literature. Five compounds, azithromycin, clarithromycin, erythromycin, sulfamethoxazole, and ibuprofen were tentatively identified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in some samples (2 to 15 %), but only ibuprofen and azithromycin could be confirmed when analyzed by liquid chromatography–high-resolution mass spectrometry (LC-HRMS) with a quadrupole-Orbitrap instrument. Concentration levels of ibuprofen in the positive samples ranged from 12 to 17 ng/L (n?=?6) while for azithromycin values from 5 to 9.5 ng/L (n?=?3) were found. Ibuprofen fragmentation behaviour in different mass spectrometry instrument configurations (triple quadrupole, quadrupole-ion trap, and quadrupole-Orbitrap) was evaluated.  相似文献   

7.
Potential threats to drinking water and water quality continue to be a major concern in many regions of the United States. New Jersey, in particular, has been at the forefront of assessing and managing potential contamination of its drinking water supplies from hazardous substances. The purpose of the current analysis is to provide an up-to-date evaluation of the occurrence and detected concentrations of methyl tertiary butyl ether (MTBE) and several other volatile organic compounds (VOCs) in public water systems, private wells, and ambient groundwater wells in New Jersey based on the best available data, and to put these results into context with federal and state regulatory and human-health benchmarks. Analyses are based on the following three databases that contain water quality monitoring data for New Jersey: Safe Drinking Water Information System (SDWIS), Private Well Testing Act (PWTA), and National Water Information System (NWIS). For public water systems served by groundwater in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 30 (2%), 21 (1.4%), and five (0.3%) of sampled systems from 1997 to 2011, respectively. For private wells in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 385 (0.5%), 183 (0.2%), and 46 (0.05%) of sampled wells from 2001 to 2011, respectively. For ambient groundwater wells in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 14 (2.1%), 9 (1.3%), and 4 (0.6%) of sampled wells from 1993 to 2012, respectively. Average detected concentrations of MTBE, as well as detected concentrations at upper-end percentiles, were less than corresponding benchmarks for all three datasets. The available data show that MTBE is rarely detected in various source waters in New Jersey at a concentration that exceeds the State's health-based drinking water standard or other published benchmarks, and there is no evidence of an increasing trend in the detection frequency of MTBE. Other VOCs, such as tetrachloroethylene (PCE), trichloroethylene (TCE), and benzene, are detected more often above corresponding regulatory or human-health benchmarks due to their higher detected concentrations in water and/or greater toxicity values. The current analysis provides useful data for evaluating the nature and extent of historical and current contamination of water supplies in New Jersey and potential opportunities for public exposures and health risks due to MTBE and other VOCs on a statewide basis. Additional forensic or forecasting analyses are required to identify the sources or timing of releases of individual contaminants at specific locations or to predict potential future water contamination in New Jersey.  相似文献   

8.
The objective of the Control of Hazardous Substances in the Baltic Sea (COHIBA) project is to support the implementation of the HELCOM Baltic Sea Action Plan regarding hazardous substances by developing joint actions to achieve the goal of “a Baltic Sea with life undisturbed by hazardous substances”. One aim in the project was to identify the most important sources of 11 hazardous substances of special concern in the Baltic Sea. Among them are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In this study, four perfluorinated alkyl acids (PFAAs) were studied: PFOA, PFOS, perfluorohexanoic acid (PFHxA) and perfluorodecanoic acid (PFDA). The occurrence of PFAAs in municipal and industrial wastewater treatment plant effluents (MWWTP1-3, IWWTP1), target industry effluent, storm water, landfill leachate and sludge was studied. Effluents were analysed six times and storm water, leachate and sludge were analysed twice, once in the warm season and once in the cold, during a 1-year sampling campaign. PFOS prevailed in two municipal effluents (MWWTP1 and 3) and industrial effluent (IWWTP1; 7.8–14, 8.0–640 and 320–1,300 ng/l, respectively). However, in one municipal effluent (MWWTP2) PFOA was, in a majority of sampling occasions, the predominant PFAA (9–15 ng/l) followed by PFOS (3.8–20 ng/l). The highest PFAA loads of the municipal effluents were found in the MWWTP3 receiving the biggest portion of industrial wastewater. In storm water the highest concentration was found for PFHxA (17 ng/l). The highest concentration of PFOS and PFOA were 9.9 and 5.1 ng/l, respectively. PFOS, PFOA and PFHxA were detected in every effluent, storm water and landfill leachate sample, whereas PFDA was detected in most of the samples (77 %). In the target industry, PFOS concentrations varied between 1,400 and 18,000 μg/l. In addition, on one sampling occasion PFOA and PFHxA were found (0.027 and 0.009 μg/l, respectively). For effluents, PFAA mass flows into the Baltic Sea were calculated. For municipal wastewater treatment plants average mass flows per day varied for PFOS between 1,073 and 38,880 mg/day, for PFOA 960 and 2,700 mg/day, for PFHxA 408 and 1,269 mg/day and for PFDA 84 and 270 mg/day. In IWWTP mass flows for PFOS, PFOA, PFHxA and PFDA were 495 mg/d, 28 mg/d, 23 mg/d and 0.6 mg/g, respectively.  相似文献   

9.
This study was aimed to determine the presence of 69 organic contaminants in 77 representative bottled waters collected from 27 countries all over the world. All water samples were contained in polyethylene terephthalate bottles. Target compounds were (1) environmental contaminants (including 13 polycyclic aromatic hydrocarbons (PAHs), 31 pesticides including organochlorine (OCPs), organophosphorus, and pyrethroids; 7 polychlorinated biphenyls (PCBs); and 7 triazines) and (2) plasticizers (including 6 phthalates and 5 other compounds). Samples were analyzed by stir bar sorptive extraction followed by gas chromatography-tandem mass spectrometry. PAHs, OCPs, PCBs, and triazines, which are indicators of groundwater pollution, were not detected in most of the samples, except for naphthalene (0.005–0.202 μg/L, n?=?16). On the other hand, plastic components were detected in 77 % of the samples. Most frequently detected compounds were dimethyl phthalate and benzophenone at concentrations of 0.005–0.125 (n?=?41) and 0.014–0.921 (n?=?32), respectively. Levels detected are discussed in terms of contamination origin and geographical distribution. Target compounds were detected at low concentrations. Results obtained showed the high quality of bottled water in the different countries around the world.  相似文献   

10.
Cloud point extraction (CPE) factors, namely Triton X-114 (TX-114) concentration, pH, ionic strength, incubation time, and temperature, were optimized for the separation of nano-sized copper(II) oxide (nCuO) in aqueous matrices. The kinetics of phase transfer was studied using UV–visible spectroscopy. From the highest separation rate, the most favorable conditions were observed with 0.2 %?w/v of TX-114, pH?=?9.0, ionic strength of 10 mM NaCl, and incubation at 40 °C for 60 min, yielding an extraction efficiency of 89.2?±?3.9 % and a preconcentration factor of 86. The aggregate size distribution confirmed the formation of very large nCuO–micelle assemblies (11.9 μm) under these conditions. The surface charge of nCuO was also diminished effectively. An extraction efficiency of 91 % was achieved with a mixture of TX-100 and TX-114 containing 30 wt.% of TX-100. Natural organic and particulate matters, represented by humic acid (30 mg/L) and micron-sized silica particles (50 mg/L), respectively, did not significantly reduce the CPE efficiency (<10 %). The recovery of copper(II) ions (20 mg/L) in the presence of humic acid was low (3–10 %). The spiked natural water samples were analyzed either directly or after CPE by inductively coupled plasma mass spectrometry following acid digestion/microwave irradiation. The results indicated the influence of matrix effects and their reduction by CPE. A delay between spiking nCuO and CPE may also influence the recovery of nCuO due to aggregation and dissolution. A detection limit of 0.04 μg Cu/L was achieved for nCuO.  相似文献   

11.
Thymol is a natural substance increasingly used as an alternative to pesticides in the fight against the Varroa destructor mite. Despite the effectiveness of this phenolic monoterpene against Varroa, few articles have covered the negative or side effects of thymol on bees. In a previous study, we have found an impairment of phototaxis in honeybees following application of sublethal doses of thymol—lower or equal to 100 ng/bee—under laboratory conditions. The present work shows the same behavioral effects on bees from hives treated with Apilife Var®, a veterinary drug containing 74 % thymol, with a decrease in phototactic behavior observed 1 day after treatment. Thus, thymol causes disruption of bee phototactic behavior both under laboratory conditions as well as in beehives. The bee exposure dose in treated hives was quantified using gas chromatography coupled to mass spectrometry (GC–MS), giving a median value of 4.3 μg per body 24 h after treatment, with 11 ng in the brain. The thymol level in 20 organic waxes from hives treated with Apilife Var® was also measured and showed that it persists in waxes (around 10 mg/kg) 1 year after treatment. Thus, in the light of (1) behavioral data obtained under laboratory conditions and in beehives, (2) the persistence of thymol in waxes, and (3) the high load on bees, it would appear important to study the long-term effects of thymol in beehives.  相似文献   

12.
Iron (Fe) is an essential element for many organisms, but high concentrations of iron can be toxic. The complex relation between iron, arsenic (As), bacteria, and organic matter in sediments and groundwater is still an issue of environmental concern. The present study addresses the effects of humic acids and microorganisms on the mobilization of iron in sediments from an arsenic-affected area, and the microbial diversity was analyzed. The results showed that the addition of 50, 100, and 500 mg/L humic acids enhanced ferrous iron (Fe(II)) release in a time-dependent and dose-dependent fashion under anaerobic conditions. A significant increase in the soluble Fe(II) concentrations occurred in the aqueous phases of the samples during the first 2 weeks, and aqueous Fe(II) reached its maximum concentrations after 8 weeks at the following Fe(II) concentrations: 28.95?±?1.16 mg/L (original non-sterilized sediments), 32.50?±?0.71 mg/L (50 mg/L humic acid-amended, non-sterilized sediments), 37.50?±?1.85 mg/L (100 mg/L humic acid-amended, non-sterilized sediments), and 39.00?±?0.43 mg/L (500 mg/L humic acid-amended, non-sterilized sediments). These results suggest that humic acids can further enhance the microbially mediated release of sedimentary iron under anaerobic conditions. By contrast, very insignificant amounts of iron release were observed from sterilized sediments (the abiotic controls), even with the supplementation of humic acids under anaerobic incubation. In addition, the As(III) release was increased from 50?±?10 μg/L (original non-sterilized sediments) to 110?±?45 μg/L (100 mg/L humic acid-amended, non-sterilized sediments) after 8 weeks of anaerobic incubation. Furthermore, a microbial community analysis indicated that the predominant class was changed from Alphaproteobacteria to Deltaproteobacteria, and clearly increased populations of Geobacter sp., Paludibacter sp., and Methylophaga sp. were found after adding humic acids along with the increased release of iron and arsenic. Our findings provide evidence that humic acids can enhance the microbially mediated release of sedimentary ferrous iron in an arsenic-affected area. It is thus suggested that the control of anthropogenic humic acid use and entry into the environment is important for preventing the subsequent iron contamination in groundwater.  相似文献   

13.
This study sampled six times of river water, sediment, and tilapia (Oreochromis niloticus) in the Dan-Shui River, Taipei, Taiwan; 10 feminizing compounds were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. Bisphenol A (508?±?634 ng/L, geometric mean (GM) 303 ng/L) and nonylphenol (491?±?570 ng/L, GM 328 ng/L) were the most abundant among analytes in the river water. Nonylphenol (770?±?602 ng/g wet weight, GM 617 ng/g wet weight) was also the highest in sediment. Fish may uptake nonylphenol and nonylphenol ethoxylates from river water and sediment because there were significant correlations between the concentrations in these matrixes and those in fish tissues (r s ranged from 0.21 to 0.49, p?相似文献   

14.
Atlantic blue fin tuna (Thunnus thynnus) is a species of great importance for Mediterranean Sea area, from both ecological and commercial points of view. The scientific literature reports few data on the contamination of this fish by emerging organic compounds such as perfluorinated alkylated substances(PFASs) and phthalates, being the latter never been studied in tuna. This study therefore investigated the presence of the PFASs perfluorooctane sulphonate (PFOS) and perfluoroctanoic acid (PFOA) and the phthalate di-2-ethylhexyl phthalate (DEHP), also monitored by its metabolite mono-2-ethylhexyl phthalate(MEHP), to assess both the state of contamination of Atlantic bluefin tuna specimen and the risk due to the toxicity of these compounds for human consumption. While PFOA was never found, detectable levels of PFOS (0.4–1.88 ng/g), DEHP (9–14.62 ng/g) and MEHP (1.5–6.30 ng/g) were found. The results were elaborated relating the accumulation to the size and age of the individuals and showed a correlation between the levels of different pollutants investigated.  相似文献   

15.
This study deals with the evaluation of water quality of the Three Gorges Reservoir (TGR) in order to assess its suitability as a raw water source for drinking water production. Therefore, water samples from (1) surface water, (2) tap water, and (3) wastewater treatment plant effluents were taken randomly by 2011–2012 in the area of the TGR and were analyzed for seven different organic contaminant groups (207 substances in total), applying nine different analytical methods. In the three sampled water sources, typical contaminant patterns were found, i.e., pesticides and polycyclic aromatic hydrocarbons (PAH) in surface water with concentrations of 0.020–3.5 μg/L and 0.004–0.12 μg/L, disinfection by-products in tap water with concentrations of 0.050–79 μg/L, and pharmaceuticals in wastewater treatment plant effluents with concentrations of 0.020–0.76 μg/L, respectively. The most frequently detected organic compounds in surface water (45 positives out of 57 samples) were the pyridine pesticides clopyralid and picloram. The concentrations might indicate that they are used on a regular basis and in conjunction in the area of the TGR. Three- and four-ring PAH were ubiquitously distributed, while the poorly soluble five- and six-ring members, perfluorinated compounds, polychlorinated biphenyls, and polybrominated diphenyl ethers, were below the detection limit. In general, the detected concentrations in TGR are in the same range or even lower compared to surface waters in western industrialized countries, although contaminant loads can still be high due to a high discharge. With the exception of the two pesticides, clopyralid and picloram, concentrations of the investigated organic pollutants in TGR meet the limits of the Chinese Standards for Drinking Water Quality GB 5749 (Ministry of Health of China and Standardization Administration of China 2006) and the European Union (EU) Council Directive 98/83/EC on the quality of water intended for human consumption (The Council of the European Union 1998), or rather, the EU Directive on environmental quality standards in the field of water policy (The European Parliament and The Council of the European Union 2008). Therefore, the suggested use of surface water from TGR for drinking water purposes is a valid option. Current treatment methods, however, do not seem to be efficient since organic pollutants were detected in significant concentrations in purified tap water.  相似文献   

16.
A method was developed for the determination of benzotriazoles (BTs) in dishwasher tabs. BTs consist of 1H-benzotriazole and/or tolyltriazole, i.e., a technical mixture of the two isomers 4-methylbenzotriazole and 5-methylbenzotriazole (5-MBT). The method consisted of weighing of an aliquot of the tab, addition of the internal standard 5-MBT, precipitation of the soaps with CaCl2 and KOH, derivatization of the filtrate with acetic acid anhydride in a two-phase system, and analysis of the organic toluene layer by gas chromatography with mass spectrometry in the selected ion monitoring mode. Eleven of 12 different dishwasher tabs from the German market were tested positive with BTs ranging from 2 to 66 mg/tab. Dishwashing experiments were performed to show that at least 99 % of the BT amount used in the dishwasher did not remain on the dishes but was released into the wastewater treatment system. The annual release of BTs into the water system was estimated to be ~80 tons. Since 70 % or less of the BTs can be degraded in wastewater treatment plants, at least 24 tons are annually released into rivers in Germany.  相似文献   

17.
18.
Triclosan (TCS) is a broad-spectrum bactericide, highly toxic to algae, which is released into the environment via wastewater effluents. Predicted no-effect concentrations (PNECs) for aquatic biota have been proposed in the literature, varying from 1.4 to 1,550 ng/L, reflecting contradicting protection goals. In this work, six rivers in the state of São Paulo were monitored for TCS and caffeine, a tracer for untreated sewage disposal, over a period of more than 1 year. From 71 samples analyzed, 32 contained TCS at concentrations above the limit of quantification, ranging from 2.2 to 66 ng/L, corresponding to a frequency of exceedance of the lowest PNEC of 86 % (six out of seven sites). No correlation between TCS and caffeine was observed, and one of the reasons for that could be the different use patterns in the local populations. Given the high values found in the investigated rivers, TCS seems to be a strong candidate in the priority list of compounds that should be regulated in Brazil to preserve the aquatic environment.  相似文献   

19.
This investigation was undertaken to compare the dissipation pattern of flubendiamide in capsicum fruits under poly-house and open field after giving spray applications at the recommended and double doses of 48 g a.i. ha?1 and 96 g a.i. ha?1. Extraction and purification of capsicum fruit samples were carried out by the QuEChERS method. Residues of flubendiamide and its metabolite, des-iodo flubendiamide, were analyzed by high-performance liquid chromatography–photodiode array, and confirmed by liquid chromatography–mass spectrometry/mass spectrometry. Limit of quantification of the method was 0.05 mg kg?1, and recovery of the insecticides was in the range of 89.6–104.3%, with relative standard deviation being 4.5–11.5%. The measurement uncertainty of the analytical method was in the range of 10.7–15.7%. Initial residue deposits of flubendiamide on capsicum fruits grown under poly-house conditions were (0.977 and 1.834 mg kg?1) higher than that grown in the field (0.665 and 1.545 mg kg?1). Flubendiamide residues persisted for 15 days in field-grown and for 25 days in poly-house-grown capsicum fruits. The residues were degraded with the half-lives of 4.3–4.7 and 5.6–6.6 days in field and poly-house respectively. Des-iodo flubendiamide was not detected in capsicum fruits or soil. The residues of flubendiamide degraded to below the maximum residue limit notified by Codex Alimentarius Commission (FAO/WHO) after 1 and 6 days in open field, and 3 and 10 days in poly-house. The results of the study indicated that flubendiamide applied to capsicum under controlled environmental conditions required longer pre-harvest interval to allow its residues to dissipate to the safe level.  相似文献   

20.
The levels of persistent organic pollutants (POPs) were determined in 50 samples of Korean human milk. POPs include organochlorine pesticides (OCPs) [aldrin, chlordanes, dieldrin, dichlorodiphenyltrichloroethanes (DDTs), endrins, heptachlors, hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), mirex, and toxaphenes] and marker PCBs (PCB28, PCB52, PCB101, PCB138, PCB153 and PCB180). In all samples, p,p′-DDE were determined as 75.5–1115.3 ng/g fat. The compounds β-HCH and p,p’-DDT were detected at 72% and 60% of the samples, respectively. Chlordanes (nd–84.9 ng/g fat) heptachlors (nd–40.1 ng/g fat), HCB (nd–42.9 ng/g fat) and PCBs (nd–38.3 ng/g fat) were detected in several samples. The ratio of dichlorodiphenyltrichloroethylene (DDE)/DDT was 6.8, which explained that exposure of volunteers to DDT did not occur recently. Compared with the previous monitoring data, the level of marker PCBs generally decreased in the milk samples. The levels of OCPs are significantly correlated to the residential periods of the mothers but not with their dietary habits. Considering the daily intake of each OCPs, 18% of infants would ingest the amount of heptachlor exceeding the acceptable daily intake (ADI) proposed by World Health Organization (WHO). There was no sample surpassing the WHO ADI for DDTs, HCB and chlordanes.  相似文献   

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