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1.
A solid‐phase extraction (SPE)‐gas chromatography (GC)‐mass spectrometry (MS) analytical method was developed for the simultaneous analysis of natural free estrogens and their conjugates in wastewater samples. Natural free estrogens and their conjugates in wastewater were successfully separated by the oasis hydrophilic‐lipophilic balance solid phase extraction (Oasis HLB SPE) method, and the conjugates were initially enzyme hydrolyzed by β‐glucuronidase or arylsulfatase from Helix pomatia prior to derivatization. N‐methyl‐N‐(tert‐butyldimethylsilyl)trifluoroacetamide (MTBSTFA) plus 1% tert‐butyldimetheylchlorosilane (TBDMCS) was chosen as the derivatization reagent, and the most appropriate conditions of derivatization were determined to be at 95°C for 90 min. The recovery ratios of nine target chemicals were determined by spiking them in 1 L of ultra‐purified water or the influent of a wastewater treatment plant (WWTP). The recovery ratios of six out of nine for the analytes ranged from 73.3–114.9% with relative standard deviations (RSD) from 1.6–19.9%. The established method was successfully applied to environmental wastewater samples which were collected from one municipal wastewater treatment plant (WWTP) in Osaka, Japan, for the determination of natural free estrogens and their conjugates. In the influent sample, E1, E2, E1‐3S, E3‐3S, and E1‐3G were detected at concentrations of 16.6, 9.6, 8.2, 21.9, and 3.2 ng L–1, respectively. However, only E1 was detected at a high concentration of 44 ng L–1 in the effluent sample, suggesting that it is the dominant natural free estrogen in the effluent.  相似文献   

2.
Occurrence of Industrial Chemicals (HPS, BPS, and SPS) in Surface Water The paper gives the results of water examinations for different phenylsulfonamides. Random samples taken every month between May 1999 and August 2000 from surface water out of the river Rhine (kilometer 838), the river Ruhr (Mülheim Styrum) and the river Emscher (Oberhausen center) were tested for the corrosion inhibiting agent 6‐[methyl(phenylsulfonyl)amino]‐hexanoic acid (HPS) as well as its metabolites 4‐[methyl‐(phenylsulfonyl)amino]‐butanoic acid (BPS) and sarkosin‐N‐(phenylsulfonyl) (SPS). Furthermore, the sewage plant effluents of two municipal wastewater treatment plants from the rural area were also included in the monitoring program. The analytical method includes solid‐phase extraction (SPE), a derivatization step as well as gas chromatography mass spectrometry (GC‐MS). SPS is regularly found in all investigated surface waters, but only occasionally in the effluents of the two rural sewage plants. The median values for SPS amount to 0.09 μg/L in the river Rhine, 0.60 μg/L in the river Ruhr, and 0.70 μg/L in the river Emscher. BPS can only be found in the river Ruhr (median value: 0.08 μg/L) and in the river Emscher (median value: 0.41 μg/L). HPS was regularly found in a surface water for the first time. This substance can be detected in the Emscher through the whole measurement period. The median value for HPS amounts to 1.78 μg/L. Aditionally, the validation characteristics of an alternative analytical method including solid‐phase microextraction (SPME) is worked out. The fully automated process includes an on‐fiber methylation step and the GC‐MS. The repeatability standard deviation of the process amounts to RSD < 12%. Detection limits between 0.07 and 0.70 μg/L are achieved.  相似文献   

3.
Determination of Organophosphorus Pesticides in Water by HPLC‐MS‐MS In the EC Water Framework Directive 2000/60/EG and in CEC 76/464/EEC there are 16 organophosphorus pesticides (insecticides and acaricides) listed which belong to so‐called priority substances. The committed quality aims of these substances frequently require maximum concentrations below 0.1 μg/L. In this paper a HPLC‐MS‐method is described. The reported limits of determination of organophosphorus pesticides are lower than the demanded limits. High analytical sensitivity is reached by solid‐phase extraction (SPE) and by injecting large volumes. For some of these substances no sample enrichment is needed and low detection limits are obtained by direct injection of the original water sample.  相似文献   

4.
Natural estrogens from humans increasingly attract attention because of their strong endocrine disrupting potency. The discharge of sewage water is considered as the most important source of these endocrine disrupting chemicals (EDCs) in the environment. Therefore, a GC‐MS method was developed for the simultaneous analysis of six natural free estrogens and their sulfate conjugates in municipal wastewater, in which natural free estrogens and sulfate conjugates were successfully separated from an Oasis HLB solid phase extraction (SPE) cartridge with two different eluents, and the sulfate conjugates were then transformed to their corresponding free estrogens by acid solvolysis. Before the analysis with GC‐MS, samples were derivatized by N,O‐bis (trimethylsilyl) trifluoroacetamide (BSTFA) plus 1% trimethylchlorosilane (TMCS) at 80°C for 40 min. Satisfactory recoveries ranging from 64 to 112.3% were obtained by spiking ultra‐purified water, raw, and treated municipal wastewater with the six estrogens at 50, 100, and 50 ng/L, respectively. The method was successfully applied to wastewater samples from one WWTP, which suggested that E1 was the dominant natural estrogens in effluent and E3‐3S was one of the conjugates possibly occurring in the effluent.  相似文献   

5.
Bioremediation is intensively studied today as a treatment method for soil contaminated with chlorinated pesticides, chemicals counted among persistent organic pollutants. In the presented work, results of desorption kinetics study using consecutive Tenax TA solid phase extraction (SPE) were tested as predictors of 3‐wk anaerobic soil bioremediation effectiveness for chlorinated pesticides γ‐HCH, DDT, and methoxychlor. Field‐contaminated samples were used in these experiments, and conditions of bioremediation tests were based on previous research. Amounts of pesticides removed during bioremediation (43–98% of initial concentrations) were in most cases much larger (average ratio 1.37) than rapidly desorbing fractions estimated in SPE using two‐compartment model of desorption kinetics. The scatter of results was also considerable (standard deviation 0.45). However, there was a statistically significant correlation between amounts removed and rapidly desorbing fractions (R2 = 0.64), indicating a relationship between degradability and desorbability. Nonetheless, determination of rapidly desorbing fractions was considered rather a poor indicator of soil bioremediation efficiency for chlorinated pesticides. The total amounts of pesticides desorbed by Tenax in 72 h performed better in this respect (R2 = 0.73, fraction removed/desorbed = 1.10 ± 0.20, average ± standard deviation). Disappearance of DDT during bioremediation was accompanied by DDD formation but this was considerably lower than results expected from stoichiometry.  相似文献   

6.
Some of the pesticides listed in the European 76/464/EC Directive and in the Directive 2000/60/EC are very polar and require special analytical methodology with respect to their extraction from water. The extraction of the organophosphorus pesticides methamidophos, omethoate, oxydemeton‐methyl, mevinphos and trichlorfon with lg POW below 1 was investigated using 21 different solid‐phase materials. Each material was tested on spiked natural water at 4 different pH values, adjusted prior to extraction. The following range of materials were tested: octadecyl silica, polymers, modified silica, ion exchange and carbon. Extraction of the above compounds from water is possible. A relationship between the octanol‐water partition coefficient and recovery rates was obtained not only for octadecyl solid phases but also for some polymeric materials. General conclusions about the use of solid‐phase materials and specific conclusions about the extraction of particular compounds were made. An optimized extraction procedure was deduced and confirmed.  相似文献   

7.
Toxic effects of five commonly used pesticides on the biomass of a municipal activated sludge system were determined on the basis of the reduction in the oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR). Toxicity levels of the selected pesticides were determined by employing a modified OECD 209 (Organisation for Economic Cooperation and Development) method which was performed as batch experiments using a respirometer. Copper sulphate (CuSO4 · 5 H2O), copper oxychloride (Cu2Cl(OH)3), copper calcium oxychloride (CaCu3Cl2(OH)6) as copper‐based pesticides and chlorsulphuron (C12H12ClN5O4S), 2,4‐dichlorophenoxyacetic acid (2,4‐D) (C8H6Cl2O3) as synthetic organic pesticides were selected for the experiments. The EC50 values were determined to be 78, 249 and 281 mg/L for CuSO4 · 5 H2O, Cu2Cl(OH)3 and CaCu3Cl2(OH)6, respectively. Corresponding values for C12H12ClN5O4S and 2,4‐D were 860 and 3664 mg/L, respectively. Results indicated that toxicity effects of copper‐based pesticides were higher than that of synthetic organic pesticides. CuSO4 · 5 H2O was found to exert the highest toxicity among the copper‐based pesticides, whereas, C12H12ClN5O4S was determined to be the most toxic among the organic pesticides on activated sludge biomass.  相似文献   

8.
A combination of denitrification and pesticide sorption with the biodegradable polymer poly(?‐caprolactone) (PCL) was examined. The function of PCL is to act as carbon source and carrier for the bacteria and simultaneously as sorbent for the pesticide endosulfan. In a short‐term examination (1 month) the addition of the pesticide endosulfan to a continuous‐flow fixed‐bed reactor resulted in an inhibition of biomass production without reduction of the denitrification performance. However in a long‐term semi‐batch reactor test (6 months) biomass production and partly denitrification rates were affected. No significant differences in microbial composition between the reactors were observed. Regardless of the type of reactor or presence of endosulfan, Acidovorax facilis was the main constituent.  相似文献   

9.
A multi‐element ion‐pair extraction method was described for the preconcentration of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) ions in environmental samples prior to their determinations by flame atomic absorption spectrometry (FAAS). As an ion‐pair ligand 2‐(4‐methoxybenzoyl)‐N′‐benzylidene‐3‐(4‐methoxyphenyl)‐3‐oxo‐N‐phenyl‐propono hydrazide (MBMP) was used. Some analytical parameters such as pH of sample solution, amount of MBMP, shaking time, sample volume, and type of counter ion were investigated to establish optimum experimental conditions. No interferences due to major components and some metal ions of the samples were observed. The detection limits of the proposed method were found in the range of 0.33–0.9 µg L?1 for the analyte ions. Recoveries were found to be higher than 95% and the relative standard deviation (RSD) was less than 4%. The accuracy of the procedure was estimated by analyzing the two certified reference materials, LGC6019 river water and RTC‐CRM044 soil. The developed method was applied to several matrices such as water, hair, and food samples.  相似文献   

10.
The rational use of pesticides generates an impact which is normally reversed and eliminated by the environment itself. However, the indiscriminate use of pesticides makes its natural degradation rhythm difficult, prolonging their presence in the soil for a great deal of time. Aiming towards a decrease in the environmental impact of pesticides, soil microorganisms capable of degrading pesticides, such as propanil, were investigated. An Enterobacter cloacae strain, isolated from rice field soil, was exposed to the herbicide propanil alone and in a mixture containing also bentazone, clomazone, quinclorac, and 2,4‐D. This bacterium was able to eliminate 100% of the applied propanil in 28 days. Propanil degradation in the 5‐herbicide mixture was much lower than that of individual pesticide degradation. The aeration of the system helped to degrade propanil and its subproduct 3,4‐dichloroaniline much faster. LC with UV detection was used to determine the remaining concentrations of the herbicides and their subproducts.  相似文献   

11.
The present work demonstrates the applicability of ferrites as photo‐Fenton catalysts for deterioration of different phenolic derivatives. To analyze optimal reaction conditions, experiments are performed with four magnetic spinel ferrites MFe2O4 (M = Co, Cu, Ni, and Zn) and two inorganic oxidants, i.e., hydrogen peroxide (HP) and potassium peroxymonosulfate (PMS). The reactions are performed using p‐nitrophenol as phenolic probe. CuFe2O4 and CoFe2O4 possessed excellent ability to activate HP and PMS, respectively, among all four synthesized catalysts. A noteworthy aspect of two oxidizing agents is that the concentration of PMS used during the reaction is four times less than HP. Further, the broad pH activity of PMS provides a significant advantage over HP. The optimal reaction conditions, when HP is the oxidant in the photo‐Fenton degradation, are 0.50 g L?1 MFe2O4, pH 2.5, and 8.8 mM HP. Although PMS is active in a wide pH range (2–10), adequate reaction conditions are 0.50 g L?1 MFe2O4, natural pH, and 2.2 mM PMS. The photo‐Fenton activity of ferrites is extended to the degradation of different nitro‐ and chloro‐analogs of phenol (2‐nitrophenol, 3‐nitrophenol, 4‐nitrophenol, 2,4‐dinitrophenol, 2,4,6‐trinitrophenol, 2‐chlorophenol, 3‐chlorophenol, 4‐chlorophenol, 2,4‐dichlorophenol) with only two ferrites (CuFe2O4 and CoFe2O4). A comparative study is performed with the two oxidants (HP and PMS) with positive results. Finally, stability and reusability of magnetic ferrites as catalysts are also studied to prove their use in phenolic solution treatment.  相似文献   

12.
Dodecylammonium bentonite (DB) and dodecylammonium sepiolite (DS) were used as sorbents for phenoxyalkanoic acid herbicides 2,4‐D ((2,4‐dichlorophenoxy)acetic acid), 2,4‐DP ((RS)‐2‐(2,4‐dichlorophenoxy)propionic acid), 2,4‐DB (4‐(2,4‐dichlorophenoxy)butyric acid), 2,4,5‐T ((2,4,5‐trichlorophenoxy)acetic acid), and MCPA ((4‐chloro‐2‐methylphenoxy)acetic acid). Langmuir, Freundlich, and the linear Henry’s Law isotherm adsorption parameters were calculated from the adsorption isotherms. Langmuir equation showed poor fit for both adsorbents. According to the evaluation using the Freundlich equation, the DS sample showed much higher and stronger sorption capacity than DB. Similar behaviour was also observed in the case of the linear Henry’s Law isotherm. The adsorption of the herbicides on both DB and DS decreased in the order of 2,4‐DB > 2,4,5‐T > 2,4‐DP > 2,4‐D > MCPA.  相似文献   

13.
Solid‐contacted Potentiometric Electrodes for Measurements of Sulfate Ions in Aqueous Solutions A solid‐contact electrode for potentiometric measurement of sulfate ions in aqueous solutions was developed and examined. The electrode is based on a PVC membrane which contains the ionophore 3‐decyl‐1,5,8‐triazacyclodecan‐2,4‐dione (DTADD). Instead of the usual inner fluid junction, a polypyrrole layer applied on the inner side of the PVC membrane was employed as inner solid contact. The performance of this electrode was compared to solid‐state sulfate‐selective electrodes with the ionophore α,α′‐bis(N′‐phenylthioureylene)‐m‐xylene (BTH) and to electrodes in the coated‐wire configuration. For the parameters sensitivity, selectivity, and long‐term stability, electrodes with the DTADD ionophore show improved properties. In the sulfate concentration range of 5·10–5...10–2 mol L–1 the slope of the response is –(26.8 ± 0.5) mV/decade. The new solid contact sulfate electrodes showed a very low drift of the electrode potential within a period of 150 days when the electrode was stored in 10–2 M Na2SO4. In Na2SO4 solutions of the pH range of 4...9 the electrode potentials were constant. The 95% response time was about 10 s when the sulfate concentration was changed from 10–4 mol L–1 to 10–3 mol L–1. The selectivity with DTADD ionophore relating to the nitrate ions is higher than the selectivity with BTH. Improvements are also made in comparison with sulfate‐selective electrodes described in the literature which contain other ionophores with fluid inner reference electrolytes.  相似文献   

14.
In this study, a new solid‐phase extraction procedure has been developed for preconcentration and determination of Co ions in different water samples by flame atomic absorption spectrometry (FAAS). Cobalt was preconcentrated as N,N′‐bis(pyridine‐2‐yl‐methyl)benzene‐1,4‐diamine (Co‐BPMBDA) from sample solutions using a column containing Amberlite XAD‐7 and was determined. In order to achieve the best performance for the method, effects of several parameters such as pH, concentrations of ligand, sample flow rate, eluent, and matrix ions on the method efficiency were investigated. Under optimum conditions, the preconcentration factor was found to be 200 for 1000 mL waters samples. Detection limit based on the 3Sb criterion was calculated as 0.24 µg/L for 100 mL of sample solution and relative standard deviation was found to be 1.8%. The method was applied to determine the trace amounts of cobalt in water samples.  相似文献   

15.
This study was designed to examine the environmental exposure of surface‐ and groundwater pollution in remote mountainous regions of northern Vietnam. In 2008, we monitored the loss of four commonly applied pesticides (imidacloprid, fenitrothion, fenobucarb, dichlorvos) from paddy rice farming systems to a receiving stream on the watershed scale and quantified groundwater pollution. For the entire monitoring period, runoff loss of pesticides from the watershed was estimated to range between 0.4% (dichlorvos) and 16% (fenitrothion) of the total applied mass. These losses were correlated well with the octanol–water partition coefficient and water solubility of pesticides (r2 = 0.78–0.99). In the groundwater collected from eight wells, all target pesticides were frequently detected. Maximum measured concentrations were 0.47, 0.22, 0.17, and 0.07 µg L?1 for fenitrothion, imidacloprid, fenobucarb, and dichlorvos, respectively. Our results strongly indicate that under the current management practice pesticide use in paddy fields poses a serious environmental problem in mountainous regions of northern Vietnam.  相似文献   

16.
Sulfate‐reduction data from various anaerobic reactor configurations, e. g., upflow anaerobic sludge blanket reactor (UASBR), completely stirred tank reactor (CSTR), and batch reactor (BR) with synthetic wastewaters, having glucose and acetate as the substrates and different levels of sulfate, were evaluated to determine the level of sulfate‐reducing activity by sulfate‐reducing bacteria coupled to organic matter removal. Anaerobic reactors were observed for the degree of competition between sulfate‐reducing sulfidogens and methane producing bacteria during the degradation of glucose and acetate. Low sulfate‐reducing activity was obtained with a maximum of 20% of organic matter degradation with glucose‐fed upflow anaerobic sludge bed reactors (UASBRs), while a minimum of 2% was observed with acetate‐fed batch reactors. The highest sulfate removal performance (72–89%) was obtained from glucose fed‐UASB reactors, with the best results observed with increasing COD/SO4 ratios. UASB reactors produced the highest level of sulfidogenic activity, with the highest sulfate removal and without a performance loss. Hence, this was shown to be the optimum reactor configuration. Dissolved sulfide produced as a result of sulfate reduction reached 325 mg/L and 390 mg/L in CST and UASB reactors, respectively, and these levels were tolerated. The sulfate removal rate was higher at lower COD/SO4 ratios, but the degree of sulfate removal improved with increasing COD/SO4 ratios.  相似文献   

17.
A new analytic methodology based on the cloud point extraction coupled with HPLC (CPE‐HPLC) was developed and successfully applied to determination of the pesticides isoproturon (IPU) and prometryne (PRO) from multi‐media (contaminated water, soil, and food vegetable). Several non‐ionic surfactants including poly ethylene glycol 6000 (PEG‐6000), TritonX‐114, and Triton X‐100 were comparatively analyzed as extraction solvents. Other parameters such as surfactant concentration, ionic strength, and equilibration temperature, and duration were also investigated. The optimal conditions for CPE were presented with 2.4% w/v PEG‐6000, 11% w/v Na2SO4 and heating assistance at 50°C for 25 min. The calibration curves for the two analytes were linear ranging from 0.001 to 10.0 mg L?1, with correlation coefficients being 0.99 determined by a HPLC–UV detector. Under the condition, the average recoveries were 85.4–90.6% for water, 84.4–92.7% for soil, and 84.4–92.1% for vegetable. Thus, the method presented here was proved to be rapid, efficient, and green for extraction and determination of isoproturon and prometryne residues from food and multi‐environmental media.  相似文献   

18.
The feasibility of pilot‐scale mineralization of organic pollutants in wastewaters using the Electro‐Fenton® process is demonstrated. The treatment was applied in a continuous‐flow reactor, to solutions of nitrobenzene, 2,4‐D and benzoic acid and to actual wastewaters from a fine chemicals company along with a pulp and paper company. The results showed mineralization yields from 60 to 84% by simply applying the Electro‐Fenton® process. When a subsequent exposure to sunlight was carried out (Helielectro‐Fenton method), this mineralization almost went to completion, except for the effluent from the fine chemicals industry.  相似文献   

19.
A pioneering investigation of semi‐volatile organic compounds (SVOCs) in shallow groundwater in China was hereby reported. Representative groundwater samples were collected from three selected regions: Eastern Hai River Plain, Yangtze River Delta, and Yunnan‐Guizhou Plateau, and analyzed for 103 SVOCs linked to agricultural and industrial practices. Analytical results showed that 70 of the 103 SVOCs were present in the groundwater samples, a detection frequency of approximately 86%. Compounds detected most frequently included P,P′‐DDT (53.49%, MDL 0.0007 µg/L), 2,4‐dinitrotoluene (51.16%, MDL 0.02 µg/L), and phenol (51.16%, MDL 0.02 µg/L). Fifteen SVOCs, such as P,P′‐DDT, 2,4‐dinitrotoluene, heptachlor, and aldrin, were detected at concentrations exceeding the USA National Recommended Water Quality Criteria‐2009 (USNRWQC‐2009). Most of these 15 SVOCs belong to polycyclic aromatic hydrocarbons and organochlorine pesticides. The detection of SVOCs in the Yunnan‐Guizhou Plateau warrants special concern, since this region has limited human activities and been assumed as an environmentally pristine area. The data from this work are expected to contribute to the database of contemporary groundwater quality in China.  相似文献   

20.
The coprecipitation method is widely used for the preconcentration of trace metal ions prior to their determination by flame atomic absorption spectrometry (FAAS). A simple and sensitive method based on coprecipitation of Fe(III) and Ni(II) ions with Cu(II)‐4‐(2‐pyridylazo)‐resorcinol was developed. The analytical parameters including pH, amount of copper (II), amount of reagent, sample volume, etc., were examined. It was found that the metal ions studied were quantitatively coprecipitated in the pH range of 5.0–6.5. The detection limits (DL) (n = 10, 3s/b) were found to be 0.68 µg L?1 for Fe(III) and 0.43 µg L?1 for Ni(II) and the relative standard deviations (RSD) were ≤4.0%. The proposed method was validated by the analysis of three certified reference materials (TMDA 54.4 fortified lake water, SRM 1568a rice flour, and GBW07605 tea) and recovery tests. The method was successfully applied to sea water, lake water, and various food samples.  相似文献   

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