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1.
Determination of Atrazine, Terbutylazine and their Deethyl- and Hydroxymetabolites in Soil by SFE and HPLC/UV-DAD The supercritical fluid extraction (SFE) (CO2 and CH3OH as modifier) of the herbicides atrazine and terbutylazine as well as their deethyl- and hydroxymetabolites from soil was investigated. The analytes were determined after extraction by HPLC/UV-DAD using a C18 column. The limits of detection of the chromatographic step were between 0.01 μg/mL and 0.07 μg/mL, the relative standard deviations between 0.8% and 1.4%. With the aid of a control chart, the stability of the chromatographic system was evaluated. For extraction, soil was spiked with 5 μg/g for each component. For SFE, CO2 and methanol as modifier were used, and a pressure program was applied. Beside SFE, Soxhlet extraction with methanol and a solid-liquid extraction with acetone/water by shaking were carried out. For chlorine-containing triazines, the recovery rates were comparable for all extraction methods. The following recovery rates for SFE were obtained: deethylterbutylazine 77.4%, terbutylazine 80.2%, deethylatrazine 87.4%, atrazine 92.6%. However, the recovery rates for the hydroxymetabolites (4.1% for hydroxyatrazine, 21% for hydroxyterbutylazine) were not satisfying compared with the “classical” methods of extraction (above 50%). The limits of detection for the total process (SFE and HPLC/UV-DAD) estimated by the signal to noise ratio amounted 0.08 μg/g soil for chlorine-containing derivates, for hydroxyatrazine 2…3 μg/g, and for hydroxyterbutylazine 0.8 μ/g.  相似文献   

2.
Two research cruises on the Baltic Sea, in July and November of 1979, were made for investigating the Baltic Sea water for its contents of dissolved cadmium, lead and copper. Atomic absorption spectrophotometry and voltammetry were used as methods of investigation, the latter method having supplied slightly lower results. In the water layer of 0 … 50 m the cadmium concentrations were 0.03 … 0.05 μg/l and the lead concentrations were 0.1 … 0.2 μg/l, seasonal changes did not have any effect on them. The copper concentrations, on the other hand, were 0.4 … 1.2 μg/l in summer and 0.1 … 0.7 μg/l in autumn. Compared with ocean waters, the lead content is remarkably high. In anoxic deep waters of the Baltic Sea the concentrations of the three metals, especially that of cadmium, are very low (< 0.01 μg/l).  相似文献   

3.
The herbicides atrazine, simazine and terbuthylazine (and the degradation product deethylatrazine) were analysed in two river-to-open-sea transects and two vertical (open-sea) profiles in the southern Baltic off Poland. Samples taken in September 1995 and April 1997 contained total triazine concentrations ranging from 7 to 31 and 4.5 to 13 ng/dm3, respectively. Concentrations of the individual compounds ranged from 0 to 8 ng/dm3. These are generally higher than levels reported, for example, in the North Sea. The largest surface concentrations were found close to the Vistula and Odra river mouths, endorsing river run-off as a primary source of the triazines. Temporal variability can be related to the late-spring and early-summer agricultural applications of the compounds. Variations in ratios between the individual triazines can be explained by usage patterns and differing residence times. Offshore vertical profiles indicate enrichment of the surface layer through atmospheric triazines inputs, highest concentrations above the halocline associated with colloidal organics and lowest concentrations in the bottom waters, probably as a result of particulate scavenging. The influence of the North Sea inflow to the Baltic is also discussed.  相似文献   

4.
The artificial sweetener acesulfame (ACE) is a potentially useful tracer of waste water contamination in groundwater. In this study, ACE concentrations were measured in waste water and impacted groundwater at 12 septic system sites in Ontario, Canada. All samples of septic tank effluent (n = 37) had ACE >6 µg/L, all samples of groundwater from the proximal plume zones (n = 93) had ACE >1 µg/L and, almost all samples from the distal plume zones had ACE >2 µg/L. Mean mass ratios of total inorganic nitrogen/ACE at the 12 sites ranged from 680 to 3500 for the tank and proximal plume samples. At five sites, decreasing ratio values in the distal zones indicated nitrogen attenuation. These ratios were applied to three aquifers in Canada that are nitrate‐stressed and an urban stream where septic systems are present nearby to estimate the amount of waste water nitrate contamination. At the three aquifer locations that are agricultural, low ACE values (<0.02‐0.15 µg/L) indicated that waste water contributed <15% of the nitrate in most samples. In groundwater discharging to the urban stream, much higher ACE values (0.2‐11 µg/L) indicated that waste water was the likely source of >50% of the nitrate in most samples. This study confirms that ACE is a powerful tracer and demonstrates its use as a diagnostic tool for establishing whether waste water is a significant contributor to groundwater contamination or not.  相似文献   

5.
Private wells in Cayuga and Orange counties in New York were sampled to determine the occurrence of pesticide contamination of groundwater in areas where significant pesticide use coincides with shallow or otherwise vulnerable groundwater. Well selection was based on local groundwater knowledge, risk modeling, aerial photo assessments, and pesticide application database mapping. Single timepoint samples from 40 wells in each county were subjected to 93‐compound chromatographic scans. All samples were nondetects (reporting limits ≤1 μg/L), thus no wells from either county exceeded any of 15 state groundwater standards or guidance values. More sensitive enzyme‐linked immunosorbent assays (ELISA) found two wells with quantifiable atrazine in each county (0.1–0.3 μg/L), one well with quantifiable diazinon (0.1 μg/L) in Orange County, and one well with quantifiable alachlor (0.2 μg/L) in Cayuga County. Trace detections (<0.1 μg/L) in Cayuga County included atrazine (five wells), metolachlor (six wells), and alachlor (one well), including three wells with multiple detections. All 12 Cayuga County wells with ELISA detections had either corn/grain or corn/forage rotations as primary surrounding land uses (although 20 other wells with the same land uses had no detections) and all quantified detections and most trace detections occurred in wells up to 9‐m deep. Orange County trace (<0.1 μg/L) ELISA detections (atrazine three wells, diazinon one well, and metolachlor five wells) and quantified detections were only generally associated with agricultural land uses. Finding acceptable drinking water quality in areas of vulnerable groundwater suggests that water quality in less vulnerable areas will also be good.  相似文献   

6.
By diluting a boggy water there is produced water with a COD-Mn of 3.4 … 10.6 mg/l O2 which is due only to humic substances. The water is mixed with 2.5 … 12.9 mg/l Cl2 at pH-values of 5.2 … 8.5 and incubated for 24 h at 20°C. CHCl3 concentrations of 38 … 480 μg/l were found by the subsequent gas-chromatographic determination. The production of chloroform can be calculated by means of a quadratic polynomial in dependence on COD-Mn, chlorine concentration and pH-value.  相似文献   

7.
The first outcomes of the national monitoring program on cyanobacteria and their toxins in the Czech Republic are reported. The concentrations of extracellular microcystins (MCs, analyzed by ELISA) in 206 water samples collected from 94 localities have been investigated. Observed MC concentrations were relatively high in comparison with the literature data, although weather conditions during the covered season (year 2004) were less favorable for the cyanobacterial water blooms. Detectable MCs (>0.125 μg/L) were found in 145 waters (70% of all samples) with a median concentration of 0.67 μg/L. The total median, including samples with no detectable MCs, was 0.26 μg/L. The seasonal trend showed an increase from July to September at most localities (maximum concentrations of about 8 μg/L and extremes up to 37 μg/L). However, a peak at the beginning of the season or continuously elevated MC concentrations were also observed at some localities. Positive correlations between increasing concentrations of MCs and the dominancy of Microcystis spp. have been observed. The survey provides the first large-scale study of the occurrence and seasonal variability of extracellular microcystins that are of particular interest for drinking water management.  相似文献   

8.
This paper reports changes in dissolved organic carbon concentration β(DOC) and the relation between UV-active and non-UV-active components determined for Elbe river water and river bank infiltrate in the Torgau river basin between 1992 and 1994. Using an ultrafiltration method, the fractionation of the DOC content was obtained for the fractions > 10 000 g/mol, 1 000…10 000 g/mol, and < 1 000 g/mol. The spectral absorption coefficient at 254 nm a254 of the molecular-weight fractions was also measured. The mean total DOC concentration of Elbe river water decreased from 6.0 mg/L to below 3.9 mg/L along two investigated flowpaths. Two thirds of the decrease occurred within the first few metres of the river bed and one third along the 350 m length of the groundwater flowpaths. The a254 values showed a significant decrease from 14.8 1/m in Elbe river water to 7.8 1/m in the aquifer. Along a flowpath, the proportion of low-molecular weight fraction of DOC increased, the proportion of high-molecular weight fraction decreased, and the proportion of the 1 000…10 000 g/mol molecular-weight fraction remained relatively stable. The Elbe river water contained the main portion of UV-active compounds in the fraction 1 000…10 000 g/mol, and this was also the case for samples of river infiltrate. For the high-molecular weight fraction, mainly non-UV-active compounds were attenuated in the river bed sediment.  相似文献   

9.
110 samples from two swimming-pools were gas-chromatographically investigated for halogenated hydrocarbons. In spite of varying chlorine concentrations between 0.1 and 2.5 mg/l Cl2 the bacteriological results were unobjectionable. The total of the haloforms was between 1.2 and 182 μg/l, with the average value of 90 μg/l. Besides CHCl3, CHBrCl2, CHBr2Cl and CCl3NO2 there were observed other, still unidentified compounds in the chlorinated bathing water which clearly are successive products of disinfection, too. The water treatment by flocculation and filtration does not bring about any elimination of trihalomethanes. Of special importance is the occurrence of trichloronitromethane in concentrations of 0.13 … 1.2 μg/l, whose LC50 in the Daphnia test is 189 μg/l, at a threshold concentration of 160 μg/l. To limit the pollution of water and air to a minimum, specific conditions must be adhered to in the operation of indoor swimming-pools.  相似文献   

10.
The lake without any outlet (11 ha, 55000 m3, zmax 2,25 m) has a weak thermal stratification with maximum surface temperatures of 32.5 °C. The annual variation of temperature and depth of visibility is unimodal, with the maxima or minima in August. Phytoplankton consists mainly of Cyanophyceae. The primary production determined by the light-dark bottle technique (oxygen method) varies in the annual variation between 0.3… 0.5 g m?2 d?1 C (winter) and 3.4… 4.6 g m?2 d?1 C (summer); as the annual means of 1975 and 1976 there were found 1.9 and 2.4 g m?2 d?1 C, resp., gross production at a utilization of 0.42… 2.85% of the radiation energy. The chemism is a well-buffered hydrogen-carbonate water (pH 8.1… 9.0) with 74… 90 mg/1 Na and 20.5… 31.5 mg/1 K and with a good nutrient supply (20… 40 μg/1 PO4—P and 100… 240 μg/1 NO3—N) at the same time.  相似文献   

11.
Several polar contaminants were found in screening analyses of 30 representative surface water samples collected from rivers, lakes, and canals in Berlin. Residues of pharmaceuticals and N-(phenylsulfonyl)-sarcosine originating from various sewage treatment plants effluents were found at concentrations up to the μg/L-level in the surface water, whereas the concentrations of polar pesticides such as dichlorprop and mecoprop were always below 0.1 μg/L. The pharmaceuticals most frequently detected in the surface water samples include clofibric acid, diclofenac, ibuprofen, propiphenazone, and two other drug metabolites. Additional investigations of groundwater wells of a drinking water plant have shown that polar contaminants such as drug residues or N-(phenylsulfonyl)-sarcosine easily leach through the subsoil into the groundwater aquifers when contaminated surface water is used for groundwater recharge in drinking water production.  相似文献   

12.
For the gas-chromatographic determination of thiocyanate in waters two enrichment processes were used: 1) the evaporation of the water sample on the water bath and 2) the adsorptive enrichment on Wofatit EA 60. As the example of the investigation of water samples from the Baltic Sea has shown, the less selective process 1 gave higher results of measurements than the adsorptive method 2. As compared with the GDR's coastal region of the Baltic (0.4 … 5.2 μg/l), the SCN? concentrations (1986) in the western offshore region (0.1 … 2.1 μg/l) are considerably lower. With increasing depth and growing salt content the SCN? concentration in the Baltic decreases. Anthropogenic influences, such as the input of residual products of sewage works effluents, can be inferred from the relatively increased SCN? concentrations in the coastal region.  相似文献   

13.
A highly sensitive and specific enzyme immunoassay (EIA) is described for the detection of the atrazine metabolite hydroxyatrazine. Polyclonal antibodies were raised in rabbits by immunization with a hapten-bovine serum albumin (BSA) conjugate containing 8 hapten residues per molecule of BSA. An EIA with a horseradish peroxidase (HRP) hapten tracer was optimized in microtitre plates. A concentration of 50% B/B0 was found at 0.10 μg/L for hydroxyatrazine. A limit of determination for hydroxyatrazine was reached at approximately 0.01 μg/L, i.e. well below the maximum concentration permitted by the EU guidelines for drinking water and the drinking water ordinance of the FRG. The assay did not require concentration or clean-up steps for drinking water or ground water samples. Validation experiments confirmed a good accuracy and precision. Hydroxyatrazine is reported to be the main atrazine metabolite found in soil samples. As organic solvents are usually employed for soil extraction, the influence of methanol as representative organic solvent on the assay was examined. Up to a concentration of 5% (v/v) methanol, the organic solvent did not affect the assay.  相似文献   

14.
Ground water in a residential area of Perth. Western Australia, was contaminated with fenamiphos and atrazine. probably as a result of the storage and handling of these chemicals at a residential properly. Sampling of existing wells indicated that atrazine and fenamiphos concentrations in ground water beneath a neighboring property were 2000 μg/L and 1000 μg/L, respectively. Fenamiphos concentrations were sufficiently high to be toxic on prolonged skin contact, and contamination posed a public health threat to nearby residents with private wells. Management of the contamination problem included restricting ground water use in the area and using a recovery well to pump contaminated ground water.  相似文献   

15.
The iodide contents in 389 ground-water-tapping plants of the county are compared with the geological character of the aquifer, the carbonate and non-carbonate hardness and the nitrate and chloride contents of the waters. 54% of the plants have I-concentrations of 3 … 7 μg/l. In the air-covered ground-water (hardness quotient<2.8) 2 … 50 μg/l I are found, whereas in the confined ground-water (hardness quotient >2.8) 2 … 50 μg/l I are contained. In general, the I-content increases with the carbonate hardness, a connection with till existing. Therefore, ground-waters of the Miocene have relatively low salt- and I-contents. Geogenic salt influences in the form of NaCl increase the I-contents to 50 … 100 μg/l. Anthropogenic influences in the residential area and due to waste increase the Cl?- and I?-concentrations. There were not detected any dependences between the I- and NO3-contents.  相似文献   

16.
In a survey in Greece from 1987 to 2000 hepatotoxic cyanobacterial blooms were observed in 9 out of 33 freshwaters. Microcystins (MCYSTs) were detected by HPLC in 7 of these lakes, and the total MCYST concentration per scum dry weight ranged from 50.3 to 1638 ± 464 μg g—1. Cyanobacterial genera (Microcystis, Anabaena, Anabaenopsis, Aphanizomenon, Cylindrospermopsis) with known toxin producing taxa were present in 31 freshwaters. From our data and a review of the literature, it would appear that Mediterranean countries are more likely 1) to have toxic cyanobacterial blooms consisting of Microcystis spp. and 2) to have higher intracellular MCYST concentrations. A case study in Lake Kastoria is used to highlight seasonal patterns of cyanobacterial and MCYST‐LR occurrence and to assess cyanotoxin risk. Cyanobacterial biovolume was high (> 11 μL L—1) throughout the year and was in excess of Guidance Level 2 (10 μL L—1) proposed by WHO for recreational waters and Alert Level 2 for drinking water. Further, surface water samples from April to November exceeded Guidance Level 3, with the potential for acute cyanobacterial poisoning. Intracellular MCYST‐LR concentrations (max 3186 μg L—1) exceeded the WHO guideline for drinking water (1 μg L—1) from September to November with a high risk of adverse health effects. Preliminary evidence indicates that in 3 lakes microcystins are accumulated in some aquatic organisms. Generally, a high risk level can be deduced from the data for the Mediterranean region.  相似文献   

17.
There is determined the LC50 for 24 … 96 h of phenol, 2,4-dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.  相似文献   

18.
Competitive solid phase enzyme immunoassays using polyclonal antibodies were developed for the detection of the phenoxycaboxylic acids MCPB [4-(4-chloro-2-methylphenoxy)butyric acid], Mecoprop [2-(4-chloro-2-methylphenoxy)propionic acid], and 2,4-D [(2,4-dichloro-phenoxy)acetic acid] in drinking water and ground water. The carrier protein for the immunization was bovine serum albumin, horseradish peroxidase conjugates were employed as enzyme tracer. For the three antisera, the optimization of detection limits and test sensitivities was our first consideration. For the mecoprop and 2,4-D antisera, the strongest influences were the pH value and the ionic strength, as much as the use of enzyme tracers with lower affinities. The MCPB antiserum reacted with 2,4-DB[4-(2,4-dichlorophenoxy)butyric acid] with equal specificity, either could be detected at 0.02 μg/L (80% B/B0), middle of the test (50 B/B0) lying at 0.1 μg/L. The detection limit with mecoprop antiserum was optimized to 0.02 μg/L, the prescribed limit for drinking water of 0.1 μg/L ling at 60 % B/B0. The strongest cross-reactivity was found for mecoprop methyl ester. MCPB. 2,4-DB, and dichloroprop have crossreactivities of 50%, 6.7%, and 6.3%, respectively. The 2,4-D antiserum reacts less sensitively with 2,4-D, the detection limit being 0.4 μg/L. The 2,4-D isooctyl ester and 2,4-D methyl ester demonstrate as cross-reacting compounds high cross-reactivites of 3630% and 2230%. The cross-reactions of the compounds 2,4-DB, MCPB, and MCPA [(4-chloro-2-methylphenoxy)acetic acid] lie at 52%, 69%, and 41%. 100 ground water tests were spiked within laboratory. All positive samples were correctly identified. Falsely negative results did not appear.  相似文献   

19.
In the catchment area of the Pomeranian Bay an average mercury concentration of 178 ng/l in precipitation was determined. Eight different flowing waters showed mean concentrations between 105 ng/l (?upawa) and 500 ng/l (Odra), a pronounced annual cycle having been demonstrated for the concentrations and for the freights with the minimum in February/March and the maximum in August/September. The total freight of the eight rivers amounts to 19.5 t/a, the share of the Wisla being 11 t/a. The ratio between the mercury precipitation of 335 to 410 μg/m2a Hg and the run-off varies of 30 … 75 μg/m2a Hg for the individual river basins between 0.08 and 0.21. In the Baltic Sea, the mercury concentrations are 40 ng/l in the open sea, 50 ng/l in the coastal region and 290 … 390 ng/l near the estuaries. Trough the eight investigated rivers about 48 km3/a water run off into the Baltic Sea with about 20 t/a Hg. The total introduction of Hg into the Baltic Sea is estimated at 100 t/a with the river water, 35 t/a with precipitation and 35 t/a with dust.  相似文献   

20.
Gao Y  Fang J  Zhang J  Ren L  Mao Y  Li B  Zhang M  Liu D  Du M 《Marine pollution bulletin》2011,62(8):1628-1631
The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants.  相似文献   

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