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PubMed1997

Determination of traces of pesticides in water by solid-phase extraction and liquid chromatography-ionspray mass spectrometry.

A multi-residue analytical method for six pesticides (atrazine, hydroxyatrazine, carbofuran, promecarb, linuron and monolinuron) in drinking water has been developed. The method combines liquid chromatography and mass spectrometry using an ionspray interface. The linearity domain, as well as the limits of detection and quantification, were determined for each compound. Although satisfactory performance could be achieved, present drinking water regulations (0.1 microgram l-1 for single pesticide) requires a pre-concentration step. This was performed using solid-phase extraction with octadecyl-bonded silica cartridges. The analytical procedure was tested on water samples spiked at the 0.04 and 0.08 microgram l-1 levels, and allowed the determination of the investigated pesticides (except hydroxyatrazine) at these trace concentrations.

Atrazine↗
PubMed2001

Determination of dichloroanilines in human urine by GC-MS, GC-MS-MS, and GC-ECD as markers of low-level pesticide exposure.

Methods for the determination of 3,4-dichloroaniline (3,4-DCA) and 3,5-dichloroaniline (3,5-DCA) as common markers of eight non-persistent pesticides in human urine are presented. 3,5-DCA is a marker for the exposure to the fungicides vinclozolin, procymidone, iprodione, and chlozolinate. Furthermore the herbicides diuron, linuron, neburon, and propanil are covered using their common marker 3,4-DCA. The urine samples were treated by basic hydrolysis to degrade all pesticides, metabolites, and their conjugates containing the intact moieties completely to the corresponding dichloroanilines. After addition of the internal standard 4-chloro-2-methylaniline, simultaneous steam distillation extraction (SDE) followed by liquid-liquid extraction (LLE) was carried out to produce, concentrate and purify the dichloroaniline moieties. Gas chromatography (GC) with mass spectrometric (MS) and tandem mass spectrometric (MS-MS) detection and also detection with an electron-capture detector (ECD) after derivatisation with heptafluorobutyric anhydride (HFBA) were employed for separation, detection, and identification. Limit of detection of the GC-MS-MS and the GC-ECD methods was 0.03 and 0.05 microg/l, respectively. Absolute recoveries obtained from a urine sample spiked with the internal standard, 3,5-, and 3,4-DCA, ranged from 93 to 103% with 9-18% coefficient of variation. The three detection techniques were compared concerning their performance, expenditure and suitability for their application in human biomonitoring studies. The described procedure has been successfully applied for the determination of 3,4- and 3,5-DCA in the urine of nonoccupationally exposed volunteers. The 3,4-DCA levels in these urine samples ranged between 0.13 and 0.34 microg/g creatinine or 0.11 and 0.56 microg/l, while those for 3,5-DCA were between 0.39 and 3.33 microg/g creatinine or 0.17 and 1.17 microg/l.

Aminoimidazole Carboxamide↗
PubMed1973

Purification and properties of an aryl acylamidase of Bacillus sphaericus, catalyzing the hydrolysis of various phenylamide herbicides and fungicides.

From Bacillus sphaericus ATCC 12123 an aryl acylamidase (EC 3.5.1.13) was purified to homogeneity by ion exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. The enzyme is inducible by various phenylamides of the acylanilide, phenylcarbamate, and methoxysubstituted phenylurea type. It has a molecular weight of 75,000. Enzyme activity was inhibited by sulfhydryl reagents, several metal ions, and 3,4-dichloroaniline (a product of linuron degradation). A requirement for divalent metal ions in enzyme activity could not be demonstrated. In the presence of 6 M urea an irreversible inactivation of the enzyme occurred. The hydrolysis of L-alanine-4-nitroanilide was competitively inhibited by puromycin.

Amides↗
PubMedDate not supplied

[3,4-dichloroaniline cometabolism by representatives of the genus Pseudomonas].

The effect of propanide, linuron and 3,4-dichloroaniline on soil organisms was studied. Two strains of Pseudomonas aurantiaca 1 and 7, were isolated from soil; they decomposed propanide yielding 3,4-dichloroaniline. These strains, as well as a number of collection cultures belonging to the Pseudomonas genus, could transform 3,4-dichloroaniline at a rate of 0-100 per cent during 48 hours. A certain correlation existed between this transformation ability and the level of total oxidase activity. All the strains of Pseudomonas studied in this work were characterized by a low peroxidase activity, and no strict correlation was detected between its level and the ability to transform 3,4-dichloroaniline.

Adsorption↗
PubMed1995

The effect of herbicides on the qualitative properties of healing plants. Part 2: Content and composition of the essential oil from Salvia officinal is L. after application of Afalon 50 WP.

The aim of our work was to study the changes of the content and quality of volatile oil in Salvia officinalis L. being treated with Afalon 50 WP (the active substance linuron) in the major ontogenetic phases of the plant growth. The plants treatment with a herbicide in pre-emergence did not cause a dramatic change in the essential oil content or in the proportional representation of its individual components. During the investigation of the changes in quality of the essential oil after an application of Afalon during various plant growth phases there was found the same relationship when compared with those being untreated.

Chromatography, Thin Layer↗
PubMed1994

Bacteria and pesticides: a new aspect of interaction--involvement of a new biofactor.

Positively charged hydrophobic pesticides of the dipyridyl family [diquat, paraquat, benzylviologen (BV++), etc.] were shown to provoke accumulation of 2-methylbutane-1,2,3,4-tetraol-2,4- cyclopyrophosphate in the cells Corynebacterium (Brevibacterium) ammoniagenes while neutral dipyridyls were not. Hydrophobicity was also an important factor in this phenomenon. Of the other pesticides tested, only linuron was effective. BV++ also induced biosynthesis of the compound in Rhodococcus rhodochrous, Rh.ruber, Rh.sp. (Nocardia corynebacteroides). These microorganisms as well as most of the previously identified oxidative stress activated producers of this new cyclopyrophosphate were able to synthesize free radical generating compounds. The microorganisms concerned belong mainly to the order Actinomycetales.

2,2'-Dipyridyl↗
PubMed1996

Metabolism of twelve herbicides by Streptomyces.

Experiments were conducted to assess the ability of Streptomyces (strain PS1/5) to metabolize twelve herbicides representing several different classes including: acetanilides, triazines, ureas, uracils, and imidazoles. Incubations in aqueous culture with dextrin as carbon source and either ammonium or Casamino acids as nitrogen source resulted in transformations (> 50%) of eight of the herbicides tested: alachlor, metolachlor, atrazine, prometryne, ametryne, linuron, tebuthiuron, and bromacil; the remaining four herbicides (cyanazine, diuron, metribuzin, and imazapyr) were also transformed, but to a lesser extent. In most instances, biotransformations occurred concurrently with growth and results were consistent regardless of the nitrogen source (ammonium vs. Casamino acids). However, in some instances there were differences in rates of biotransformation as a consequence of the nitrogen source (e.g. alachlor, metribuzin), suggesting the selective induction of certain metabolic enzymes; in other instances biotransformations were not associated with growth, suggesting secondary metabolism. An experiment was also conducted to assess the ability of Streptomyces (strain PS1/5) to metabolize atrazine contaminated soil. Inoculation of soil amended with 20 micrograms/g of atrazine and 5% chitin as carbon source resulted in ca. 78% removal of atrazine within 28 days. These data suggest that Streptomyces species may be potential candidates for soil inoculation to bioremediate herbicide contaminated soils.

Biodegradation, Environmental↗
PubMed1980

[Herbicide residues in some herbs (author's transl)].

Residue occurrence is discussed with use of 14 herbicides (Alachlor, Chloridazone, Chlorpropham, Chloroxuron, Chlorthal-methyl, Desmetryne, Lenacil, Linuron, Methabenzthiazuron, Monolinuron, Na-propamide, Pendimethalin, Phenmedipham and Terbutryne) on 6 herbs (borage, dill, garden-chervil, garden cress, anise and sorrel) in the light of residue analyses (from field trials over two seasons with analyses carried out in two laboratories). The methods are outlined; limits of the determinations and recoveries are given.

Carbamates↗
PubMed1975

Effect of pesticides on blue-green algae and nitrogen-fixation.

The effects of the pesticides, amitrol, a derivative of amitrol (viz. 3,5-diamino-1,2,4-triazole), diquat, paraquat, linuron, MCPA, malathion, and monuron, were studied on the nitrogen-fixing algae, Anabaena cylindrica, Aulosira sp., Calothrix elenkenii. Chlorogloeae frischii, Cylindrospermum muscicola, Nostoc sp. from Collema tenax, Nostoc muscorum Tolypothrix tenuis, and Westiellopsis sp. In general, two types of response were discernible; an initial period of depression succeeded by an increased activity and an initial period of depression followed by a distinct decrease on prolonged incubation. The results indicate that some pesticidal compounds can severely limit the nitrogen-fixing capacities of blue-green algae, thereby affecting the overall nitrogen economy of soils in general.

Culture Media↗
PubMed1999

Sorption of Nine Pesticides to Three Aquatic Macrophytes.

The sorption of nine pesticides to the aquatic macrophytes Chara globularis, Elodea nuttallii, and Lemna gibba was studied. A batch equilibrium method was used to study the sorption at five concentration levels to fresh shoots of the macrophytes. The results for the herbicides atrazine and linuron were described by nonlinear Freundlich equations, with Freundlich exponents ranging from 0.53 to 0.60. The results for the other compounds showed almost linear sorption isotherms, with Freundlich exponents ranging from 0.9 to 1.1. The highest sorption was measured for chlorpyrifos, with sorption coefficients ranging from 1,660 to 2,150 L/kg. Sorption coefficients for C. globularis tended to be lower than those for the other two macrophytes. Correlation (R(2) = 0.80) was found for the relation between the sorption coefficient (K(d)) of six pesticides and their solubility in water (S). The equation log K(d) = 3.20 - 0.65 log S can be used for a first estimate of the sorption coefficient of a pesticide to aquatic macrophytes.http://link.springer-ny.com/link/service/journals/00244/bibs/37n3p310.html

Journal Article↗
PubMed1993

Solid-phase extraction followed by high-performance liquid chromatographic analysis for monitoring herbicides in drinking water.

A multiresidue analytical method based on C18 solid-phase extraction and one-run HPLC determination has been developed for the analysis of eleven acidic, neutral and weak basic herbicides in drinking water. A 1-1 sample of water was preconcentrated by passage through a 500-mg C18 solid phase extraction column. The retained compounds were eluted from the column with 1 ml of methanol. After concentration of the extract the pesticides were separated and quantified by reversed-phase HPLC with UV detection. Bentazone, 2,4-D, MCPA, fluazifop-acid, metoxuron, monolinuron, metobromuron, diuron, linuron, atrazine and simazine were determined simultaneously in a single run on a C18 HPLC column. Reanalyses of the sample extracts on a second cyano column were used to confirm the identity of the neutral and basic compounds. The limit of determination, defined as four times the baseline noise, varied between 0.01 microgram/l and 0.1 microgram/l depending on the compound, the detection sensitivity of the instrument and the type of HPLC column used.

Chromatography, High Pressure Liquid↗
PubMed1994

Separation and detection of herbicides in water by micellar electrokinetic capillary chromatography.

The herbicides linuron, metolachlor, atrazine and metsulfuron were analysed using micellar electrokinetic capillary chromatography (MECC) after a 1000-fold concentration step by solid-phase extraction (SPE). Recoveries ranged from 80 to 92%, depending on the concentration and the number of active substances in the sample. Furthermore, the hydrolysis products of metsulfuron were analysed by MECC and by gas chromatography-mass spectrometry (GC-MS). Representative MECC and GC-MS profiles are shown and the structures of the hydrolysis products are proposed on the basis of their chromatographic and mass spectra features. A tentative pathway for the degradation of metsulfuron is proposed.

Chromatography↗
PubMed1998

Simultaneous quantitative determination of thirteen urea pesticides at sub-ppb levels on a Zorbax SB-C18 column.

A simple multi-residue method is described for simultaneously determining ten urea and three benzoylurea pesticides residues in drinking water with quantitation limits below the European regulatory limit of 0.1 microgram/l. The residues were extracted from drinking water with dichloromethane and analysed by HPLC on a Zorbax 5 microns SB-C18 column with diode array detection (DAD) at 240 nm. Recoveries were determined by spiking drinking water with 13 pesticides (benzthiazuron, metoxuron, monuron, fluometuron, isoproturon, diuron, linuron, chloroxuron, chlorbromuron, diflubenzuron, neburon, triflumuron and flucycloxuron) at the 0.05-0.50 microgram/l level.

Chromatography, High Pressure Liquid↗
PubMed1997

Evaluation of ELISA microtiter plate-based assays for the direct determination of isoproturon in water samples and soil extracts.

Trials were carried out on the commercially available Millipore isoproturon ELISA microtiter plate tests and on laboratory assays developed by Hirst as part of a Joint European Union research project (BIOPTICAS). The lowest detectable dose (LDD) was determined as three times the standard deviation of the blanks. Depending on the calibration curves obtained on different days with different plates, the LDD varied from 0.020 to 0.064 microgram/L for the Millipore test and from 0.080 to 0.329 microgram/L for the Hirst test. The mean coefficients of variation within a single plate for triplicate determinations of standard solutions in the 0.05 to 0.5 microgram/L range were 5.5 and 3.6% for Millipore and Hirst respectively. Cross-reactivity was studied for mono- and di-demethylated isoproturon, chlortoluron, diuron and linuron. The highest cross-reactivity with both tests was that of mono-demethylated isoproturon (22% for Millipore, 4% for Hirst). This molecule was the only one to show significant cross-reactivity in the Hirst test, whereas in the Millipore test, the di-demethylated isoproturon also cross-reacted (4%). Natural water samples, 19 ground-, 53 lysimetric plate and 47 suction cup water samples, and 32 soil samples were also analysed with the ELISA tests. HPLC with a diode array detector was used as a validated control technique for the natural samples. For each water type, ELISA concentrations of both tests were significantly correlated with the HPLC values (r > or = 0.937; p < 0.001). For the soil extracts, the correlations were also significant (p < 0.001), but the scatter in the data was greater. Overall, the Millipore correlation coefficients were higher than those of Hirst.

Antibodies↗
PubMed1999

A field study to compare performance of stainless steel research monitoring wells with existing on-farm drinking water wells in measuring pesticide and nitrate concentrations.

Existing drinking water wells are widely used for the collection of ground water samples to evaluate chemical contamination. A well comparison study was conducted to compare pesticide and nitrate-N data from specially designed stainless steel research monitoring wells with data from nearby existing on-farm drinking water wells. Results could help to determine whether adequate information concerning ground water contamination can be obtained from existing drinking water wells for use in making pollutant control decisions. The study was conducted during 1993-1994 in the Little Coharie Watershed, a 158 square mile area located in the coastal plain of eastern North Carolina. Statistical analysis indicated that research monitoring wells provided a greater probability of detecting pesticides in ground water than existing on-farm wells. Atrazine was the most frequently detected pesticide found in all wells, followed in order by fluometuron, carbofuran, metolachlor, alachlor, carbaryl, butylate, chlorothalonil, linuron and simazine. Ninety-seven percent of all wells had observed concentrations of nitrate-N, ranging from 0.1 to 30.1 mg/L. There was not a significant difference between research wells and existing wells for monitoring nitrate-N. Based on results of this study, existing drinking water wells can be used for monitoring nitrate; however, specialized stainless steel monitoring wells should be used for monitoring pesticides in ground water.

Databases, Factual↗
PubMed2000

The distribution of micro-organic contaminants in river bed-sediment cores.

There is little information available on the distributions of micro-organic contaminants in river bed-sediments below a depth of 5 cm. The aim of this study is to determine the concentrations and distributions of contaminants in river bed-sediments up to 1 m depth and to make an assessment of the results. The approach taken was to collect five cores from each of two lowland rivers in southern England, the first a rural river and the second a dominantly urban catchment. The cores were analysed for micro-organic compounds and sediment/sediment porewater characteristics. Compounds detected were polyaromatic hydrocarbons (naphthalene, fluoranthene and pyrene), pesticides (carbaryl, linuron, fenpropimorph, the synthetic pyrethroids, and prometryn), and non-ionic surfactant residue (nonylphenol). A particularly important finding was that some micro-organic contaminants penetrated to depths of 1 m, and in one of the rivers they were detected in undisturbed Eocene substrata. The more hydrophobic contaminants showed a clear depth distribution with higher concentrations towards the top of the cores. The less hydrophobic contaminants demonstrated no systematic trend suggesting they had become soluble in porewaters and subsequently travelled within the cores. Partition between the porewater and sediment appeared to be controlling the distribution of the compounds with depth.

England↗
PubMed2001

Environmental xenoestrogens, antiandrogens and disorders of male sexual differentiation.

Over the past 20 years, the documented increase in the disorders of male sexual differentiation, such as hypospadias, cryptorchidism, and micropenis, has led to the suspicion that environmental chemicals are detrimental to normal male genital development in utero. Male sexual differentiation is critically dependent on the normal action of androgens, and unbalanced androgen/estrogen ratios can disturb it. Environmental xenoestrogens (such as herbicides, pesticides, PCBs, plasticizers, and polystyrenes) that mimic estrogens or environmental antiandrogens (such as polyaromatic hydrocarbons, linuron, vinclozolin, and pp'DDE) that disturb endocrine balance, cause demasculinizing effects in the male foetus. These environmental chemicals are often referred to as endocrine disruptors: they are thought to mimic endogenous estrogens by entering the cell, binding to the receptor and activating transcription, they may also antagonize normal androgen action. We have established numerous cell lines to assess the estrogenicity and antiandrogenicity of compounds found in the environment and to identify new products present in wastewater effluents that are able to disrupt endocrine functions. Several cell lines responding to estrogens have been obtained in our group, including cells with different enzymatic equipment and cells expressing chimeric receptor or natural estrogen receptors alpha and beta. These cell lines have proved to be useful for assessing the biological activity of pesticides, fungicides, and chemicals found in plastic or discarded in the environment. In order to generate a powerful tool for the investigation of androgen action and the rapid screening of potential antagonists, we developed a new stable prostatic cell line. The PALM cell line is an original cellular model to characterize the response of hAR, and it provides an easy and rapid bioluminescent test to identify new antagonists. We also developed a model based on a fusion protein between the androgen receptor (AR) and the green fluorescent protein (GFP) to study the intracellular dynamics of AR. The GFP-AR model was applied to define the ability of several xenoestrogens and antiandrogens to inhibit the nuclear transfer of AR. The ubiquitous presence of endocrine disruptors in the environment and the increased incidence of neonatal genital malformation support the hypothesis that disturbed male sexual differentiation may in some cases be caused by increased exposure to environmental xenoestrogens and/or antiandrogens.

Androgen Antagonists↗