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A character in a famous William Shakespeare play commented that “a great cause of the night is lack of the sun”. (1) Shakespeare used the comment as a statement and a humorous device, which we refer to here as we wish to address reasons why there is perhaps more humor and less illumination in the increasing use of the phrase “potentially toxic element”. Usage of this phrase gained momentum after a 2002 International Union of Pure and Applied Chemist’s publication criticizing the use of the term “heavy metal” to describe metals/metalloids “and their compounds [that] have highly toxic or ecotoxic properties”. (2) The 2002 paper was a scholarly work that carefully analyzed the use of heavy metal in the context of existing definitions, intended meaning, and possible consequences of using a phrase not unequivocally defined to describe hazardous substances. Throwing the proverbial baby out with the baby’s bathwater, we now have the alternative of a less useful phrase. While “toxic element” certainly addresses the concept of toxic and that not all heavy metals are strictly speaking metals, what is not “potentially” toxic? People have died from star fruit poisoning, carrot juice addiction, and water intoxication. (3−5) This global descriptor admits nothing to differentiate the relatively benign iron (Fe), or even sodium (Na), from lead (Pb) and cadmium (Cd), that is, metals toxic at relatively low dosages and simultaneously most frequently referred to as “potentially toxic elements”. Under this “helpful” classifier of “potentially”, we lack a definitive basis for not counting star fruit, carrot juice, or water as potentially toxic, and we, the authors of this Viewpoint, could be said in all factual validity to be potentially intergalactic travelers. As the famous ecological economist Herman Daly pointed out “One way to render any concept innocuous is to expand its meaning to include everything... Any definition that excludes nothing is a worthless definition”; that is, a definition that means everything, means nothing., This work was supported in part by the National Natural Science Foundation of China (Grant No. 42107245). We thank those who provided constructive commentary for revision of this article, including the editor Prof. Li, one or more anonymous reviewer(s), and D. Phillips.

Antibiotic transformation products (TPs) generated during water treatment can be considered as an environmental concern, since they can retain part of the bioactivity of the parent compound. Effect-directed analysis (EDA) was applied for the identification of bioactive intermediates of azithromycin (AZI) and ciprofloxacin (CFC) after water chlorination. Fractionation of samples allowed the identification of bioactive intermediates by measuring the antibiotic activity and acute toxicity, combined with an automated suspect screening approach for chemical analysis. While the removal of AZI was in line with the decrease of bioactivity in chlorinated samples, an increase of bioactivity after complete removal of CFC was observed (at >0.5 mgCl2/L). Principal component analysis (PCA) revealed that some of the CFC intermediates could contribute to the overall toxicity of the chlorinated samples. Fractionation of bioactive samples identified that the chlorinated TP296 (generated from the destruction of the CFC piperazine ring) maintained 41%, 44%, and 30% of the antibiotic activity of the parent compound in chlorinated samples at 2.0, 3.0, and 4.0 mgCl2/L, respectively. These results indicate the spectrum of antibacterial activity can be altered by controlling the chemical substituents and configuration of the CFC structure with chlorine. On the other hand, the potential presence of volatile DBPs and fractionation losses do not allow for tentative confirmation of the main intermediates contributing to the acute toxic effects measured in chlorinated samples. Our results encourage further development of new and advanced methodologies to study the bioactivity of isolated unknown TPs to understand their hazardous effects in treated effluents., This work was funded by the Spanish State Research Agency of the Spanish Ministry of Science, Innovation and Universities AEI-MICIU and the Fondo Europeo de Desarrollo Regional under the National Program for Research Aimed at the Challenges of Society (CTM2017-85335-R). Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (ICRA-ENV 2017 SGR 1124 and 2017-SGR-1404). ICRA researchers thank funding from CERCA program. M.J.F and S.R.M. acknowledge the Ramon y Cajal research fellowships RyC-2015-17108 and RYC-2014-16707 from the Spanish Ministry of Economy and Competitiveness. A.J.G. and A.S.C acknowledges the predoctoral grants 2019FI_B2_00202 and 2018FI_B2_00170 from AGAUR and co-financed by the European Social Fund. The authors would like to Wageningen Food Safety Research for their help with the antibiotic inhibition tests.

© 2016 American Chemical Society. Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant concentrations - where observing outcomes is difficult - versus higher ENM doses, where responses are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? These questions were addressed in the context of this critical review. As a result, three main recommendations emerged. First, researchers should improve ecotoxicology of ENMs by choosing test end points, duration, and study conditions - including ENM test concentrations - that align with realistic exposure scenarios. Second, testing should proceed via tiers with iterative feedback that informs experiments at other levels of biological organization. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.

Dechlorane Plus (DP) is a proposed alternative to the legacy flame retardant decabromodiphenyl ether (BDE-209), a major component of Deca-BDE formulations. In contrast to BDE-209, toxicity data for DP are scarce and often focused on mice. Validated dietary in vivo exposure of the marine bivalve (Mytilus galloprovincialis) to both flame retardants did not induce effects at the physiological level (algal clearance rate), but induced DNA damage, as determined by the comet assay, at all concentrations tested. Micronuclei formation was induced by both DP and BDE-209 at the highest exposure concentrations (100 and 200 μg/L, respectively, at 18% above controls). DP caused effects similar to those by BDE-209 but at lower exposure concentrations (5.6, 56, and 100 μg/L for DP and 56, 100, and 200 μg/L for BDE-209). Moreover, bioaccumulation of DP was shown to be concentration dependent, in contrast to BDE-209. The results described suggest that DP poses a greater genotoxic potential than BDE-209.

At present, there is a lack of understanding of the combined ecotoxicity of carbon-based nanomaterials and co-contaminants. In this paper, we report on the toxicity of three carbon nanomaterials (fullerene-soot, multiwall carbon nanotubes, and graphene). Two standardized toxicity bioassays, the immobilization of the invertebrate Daphnia magna and the bioluminescence inhibition of the marine bacteria Vibrio fischeri, have been used. Synergistic and antagonistic effects of binary mixtures composed of fullerene soot and organic co-contaminants as malathion, glyphosate, diuron, triclosan, and nonylphenol were assessed. The isobologram method was used to evaluate the concentrations producing an effect, in comparison to those effects expected by a simple additive approach. In this study, antagonism was the predominant effect. However, synergism was also observed as in the case of D. magna exposed to mixtures of malathion and fullerene soot. D. magna was shown to be the most sensitive assay when carbon nanomaterials were present. Toxicity to D. magna was as follows: fullerene soot > multiwall carbon nanotubes > graphene. These results were proportional to the size of aggregates, smaller aggregates being the most toxic. The vector function of nanomaterials aggregates and the unexpected release inside living organisms was proven for malathion. These results highlight new insights on the risks associated with the release of carbon nanomaterials into the environment.

Wastewater and surface water samples, extracted with four solid-phase extraction cartridges of different chemistries, were suspect-screened for the anticonvulsant lamotrigine (LMG), its metabolites, and related compounds. LMG, three human metabolites, and a LMG synthetic impurity (OXO-LMG) were detected. Preliminary results showed significantly higher concentrations of OXO-LMG in wastewater effluent, suggesting its formation in the wastewater treatment plants (WWTPs). However, biodegradation experiments with activated sludge demonstrated that LMG is resistant to degradation and that its human metabolite lamotrigine-N(2)-glucuronide (LMG-N2-G) is the actual source of OXO-LMG in WWTPs. In batch reactors, LMG-N2-G was transformed, following pseudo-first-order kinetics to OXO-LMG and LMG, but kinetic experiments suggested an incomplete mass balance. A fragment ion search applied to batch-reactor and environmental samples revealed another transformation product (TP), formed by LMG-N2-G oxidation, which was identified by high-resolution mass spectrometry. Accounting for all TPs detected, a total mass balance at two concentration levels in batch reactors was closed at 86% and 102%, respectively. In three WWTPs, the total mass balance of LMG-N2-G ranged from 71 to 102%. Finally, LMG-N2-G and its TPs were detected in surface water samples with median concentration ranges of 23-139 ng L(-1). The results of this study suggest that glucuronides of pharmaceuticals might also be sources of yet undiscovered, but environmentally relevant, transformation products.

The introduction of drinking water disinfection greatly reduced waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water leads to an unintended consequence, the formation of drinking water disinfection byproducts (DBPs). The haloace-taldehydes (HALs) are the third largest group by weight of identified DBPs in drinking water. The primary objective of this study was to analyze the occurrence and comparative toxicity of the emerging HAL DBPs. A new HAL DBP, iodoacetaldehyde (IAL) was identified. This study provided the first systematic, quantitative comparison of HAL toxicity in Chinese hamster ovary cells. The rank order of HAL cytotoxicity is tribromoacetaldehyde (TBAL) ≈ chloroacetaldehyde (CAL) > dibromoacetaldehyde (DBAL) ≈ bromochloroacetaldehyde (BCAL) ≈ dibromochloroacetaldehyde (DBCAL) > IAL > bromoacetaldehyde (BAL) ≈ bromodichloroacetaldehyde (BDCAL) > dichloroacetaldehyde (DCAL) > trichloroacetaldehyde (TCAL). The HALs were highly cytotoxic compared to other DBP chemical classes. The rank order of HAL genotoxicity is DBAL > CAL ≈ DBCAL > TBAL ≈ BAL > BDCAL > BCAL ≈ DCAL > IAL. TCAL was not genotoxic. Because of their toxicity and abundance, further research is needed to investigate their mode of action to protect the public health and the environment.

Concentrations of Dechlorane (Dec) 603 (0.75 ng/g lipid weight (lw); mean) and Dec 602 (0.38 ng/g lw; mean) were quantified in more than 95% of the franciscana (Pontoporia blainvillei) dolphin samples, whereas the frequency of detection decreased to 75% for Dechlorane Plus (DP) (1.53 ng/g lw, mean). The presence of Chlordene Plus (CP) was also observed (0.13 ng/g lw, mean) in half of the samples. On the contrary, Dec 604, decachloropentacyclooctadecadiene (aCl(10)DP), and undecachloropentacyclooctadecadiene (aCl(11)DP) concentrations were below the limit of quantifications in all cases. To the best of our knowledge, this is the first article reporting the presence of Dec 603, Dec 602, and CP in mammals. For comparative purposes, levels of Mirex, polybrominated diphenyl ethers (PBDEs), and decabromodiphenylethane (DBDPE) are also reported. Considering geographic distribution evaluation together with the strong positive correlations found between DP and PBDEs (r(s) = 0.63; p < 0.01), highly anthropogenic areas were identified as potential sources of these chemicals in this dolphin species. However, local sources for Dec 602, 603, Mirex, CP, and DBDPE were not found indicating that in this case historical use and/or atmospheric transport and deposition may play an important role in their fate.

When considering joint toxic apical effects at higher levels of biological organization, such as the growth of populations, the so-called pharmacological mode of action that relies on toxicological mechanistic effects on molecular target sites may not be relevant. Such effects on population growth rate will depend on the extent to which juvenile and adult survival rates and production rates (juvenile developmental rates and reproduction) are affected by toxic exposure and also by the sensitivity of population growth rates to life-history changes. In such cases, the ecotoxicological mode of action, defined as the crucial life-history trait processes and/or xenobiotic-life-history trait interactions underlying a toxicological effect on population growth rate, should be considered. Life-table response experiments with the crustacean Ceriodaphnia dubia exposed to single and ternary mixtures of nine compounds were conducted to test the hypothesis that joint effects on population growth rates could be predicted from the mixture constituent ecotoxicological mode of action. Joint effects of mixtures containing pharmacologically dissimilar compounds (cadmium, λ-cyhalothrin, and chlorpyrifos) that differentially affected life-history traits contributing to population growth rates were accurately predicted by the independent-action concept. Conversely, the concentration-addition concept accurately predicted joint effects of two different mixtures: one containing pharmacologically similar acting pyrethroids that also affected similarly life-history traits, the other one that included pharmacologically dissimilar compounds (3,4-dichloroaniline, sodium bromide, and fenoxycarb) acting mainly on reproduction rates. These results indicate that when assessing combined effects on population growth rate responses, selection of mixture toxicity conceptual models based on the ecotoxicological mode of action of mixture constituents provided more accurate predictions than those based on the pharmacological mode of action.

This work describes the assessment of a selection of fullerenes including C(60) and C(70) fullerene, N-methylfulleropyrrolidine, C(60) pyrrolidine tris-acid ethyl ester, [6,6]-Phenyl-C(61) butyric acid butyl ester and [6,6]-Thienyl C(61) butyric acid methyl ester, in airborne particulate from the Mediterranean Sea collected during two sampling campaigns from Barcelona to Istanbul and Alexandria, respectively. The analysis of the samples was carried out using a new method based on liquid chromatography coupled to mass spectrometry (LC-MS) presenting sensitivities between 5.4 and 20.9 pg/m(3). A total number of 43 samples covering the different basins of Mediterranean Sea were analyzed. Fullerenes were detected in all analyzed samples and quantifiable concentrations were found in 28 of the analyzed samples. The median of C(60) and C(70) fullerenes aerosol phase concentrations were 0.06 ng/m(3) and 0.48 ng/m(3) respectively for the Mediterranean Sea atmosphere. C(70) fullerene was the most frequently detected compound and also it was found in the higher concentrations for most samples, reaching 233.8 ng/m(3). The modeled back-trajectories disclose that those samples with higher concentrations of fullerenes were related to air masses which had been circulating over regions with an intense industrial activity, but the variability of the C(70)/C(60) ratio suggests multiple different sources. These results are related to the incidental emissions from urban and industrial development, underpinning the need of studying the possible risks associated to carbon nanoparticles in the environment and the need of evaluating the possible consequences of their ubiquitous occurrence.

Soils are a major reservoir of organic pollutants, and soil-air partitioning and exchange are key processes controlling the regional fate of pollutants. Here, we report and discuss the soil concentrations of polycyclic aromatic hydrocarbons (PAHs), their soil fugacities, the soil-air partition coefficients (K(SA)) and soil-air gradients for rural and semirural soils, in background areas of N-NE Spain and N-NW England. Different sampling campaigns were carried out to assess seasonal variability and differences between sampling sites. K(SA) values were dependent on soil temperature and soil organic quantity and type. Soil fugacities of phenanthrene and its alkyl homologues were 1-2 orders of magnitude higher than their ambient air fugacities for all sampling sites and periods. The soil to air fugacity ratio was correlated with soil temperature and soil redox potential. Similar trends for other PAHs were found but with lower fugacity ratios. The ubiquitous source of PAHs from background soils to the atmosphere found in all temperate regions in different seasons provides an indirect evidence of potential in situ generation of two to four ring PAHs and their alkyl homologues in the surface soil. We discuss this hypothetical biogenic source and other potential processes that could drive the high soil to air fugacity ratios of some PAHs.

In this work the photodegradation pathways and rates of oseltamivir ester (OE) and oseltamivir carboxylate (OC) were studied under artificial and natural solar irradiation with the goal of assessing the potential of photolysis as a removal mechanism in aquatic environments. The structures of the photoproducts of OE, elucidated by ultra performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-QToF-MS), were proposed to originate from hydration of the cyclohexene ring (TP330), ester hydrolysis (TP284), a combination thereof (TP302), intramolecular cyclization involving the ester (TP312), and cleavage of the ethylpropoxy side chain (TP226). The only photoproduct detected in case of OC was postulated to correspond to the hydration of the α,β-unsaturated acid (TP302). Under simulated solar irradiation the degradation rate of OC was approximately 10 times slower than that of OE, with half-lives ranging from 48 h in ultrapure water to 12 h in surface water from Sant Joan Despi, Llobregat river. The photodegradation under natural solar irradiation during the season of pandemic Influenza peak incidence was about 150 days for OC and 15 days for OE. In general, the photoproducts proved to be more resistant toward further photodegradation than the parent antivirals. In a monitoring survey of surface waters from the Ebro river (NE Spain), OC and OE were detected along with the photoproducts TP330 and 312.

8 pages, 3 figures.-- Printed version published Mar 15, 2009., Samples of human breast milk (n = 33) from A Coruña (NW of Spain) collected in 2006 and 2007 were analyzed for HBCD diastereoisomers and enantiomers. HBCD was detected in 30 out of 33 human milk samples, at concentration levels ranging between 3 and 188 ng/g lw, with a median value of 27 ng/g lw, showing higher levels than those published for other countries. Diastereoisomeric pattern shows the predominance of the γ-isomer, with low contribution of the α-isomer and the β-isomer being below the limit of quantification. However, in six samples, there is a dominance of the α-isomer versus the γ-isomer. For the first time, HBCD enantiomeric analysis was carried out in human breast milk samples, showing a selective enantiomeric enrichment in human body. As regards α-HBCD, an enrichment of (−)-enantiomer was observed. However, in the case of γ-HBCD, no clear preference for one or the other enantiomer was found. Finally, and based on the calculated HBCD concentrations in human breast milk from Spain, the daily ingestion rate of HBCD was estimated. The nursing infant dietary intake for HBCD was set at 175 ng (kg of body weight)−1 day−1., This research project was funded by the European Union under the "Contaminants in food and feed: inexpensive detection for control of exposure" project (CONffIDENCE, Project 211326). P.G. acknowledges a grant from Department d’Innovació, Universitats i Empresa (2008FI_B 00755).

Polyethoxylated nonylphenol (NPEOx) surfactants and nonylphenol (NP) as their major degradation product as well as some synthetic and natural estrogens and progestogens have been reported to be present in freshwater systems, mainly at the vicinity of urban discharges and sewage treatment plants (STPs), at levels high enough to exhort estrogenicity to wildlife. To determine both presence and effects of such compounds in two tributaries of the Llobregat river (NE Spain), water samples and carp, Cyprinus carpio, were collected from selected sites along a transect, for chemical and biological determinations, respectively. Also influent and effluent water from several STPs, discharging into these rivers, was collected for its chemical characterization. NP and NPEO were determined by solid-phase extraction (SPE) followed by liquid chromatography−mass spectrometry (LC-MS). Representative estrogens, both natural (estradiol, estriol, estrone) and synthetic (ethynyl estradiol, mestranol, diethylstilbestrol), proges...

Multivariate correlations between the concentrations of selected herbicides and herbicide derivatives in outflows from selected reservoirs in the Midwestern United States for April 1992 through September 1993 were investigated using principal component analysis (PCA) and multivariate curve resolution (MCR). Two independent sources for alachlor ethanesulfonic acid, one major source related to spring flush and seasonal runoff and another minor source related to groundwater, were identified using PCA. Results of MCR provided a semiquantitative interpretation of the environmental sources of the observed herbicide concentrations in reservoir outflows and allowed the examination of their temporal and geographical distributions. Samples with higher herbicide concentrations were collected from reservoirs in Indiana and Ohio, especially during the late spring and summer.

Cyanazine and two of its major metabolites, cyanazine amide and cyanazine acid, were measured at trace levels in groundwater using liquid chromatography/atmospheric pressure chemical ionization/mass spectrometry (LC/APCI/MS). Solid-phase extraction was carried out by passing 20 mL of groundwater sample through a cartridge containing a polymeric phase (PLRP-s), with recoveries ranging from 99 to 108% (n = 5). Using LC/MS detection in positive ion mode, useful structural information was obtained by increasing the fragmentor voltage, thus permitting the unequivocal identification of these compounds in groundwater samples with low sample volumes. The fragmentation of the amide, carboxylic acid, and cyano group was observed for both metabolites and cyanazine, respectively, leading to a diagnostic ion at m/z 214. Method detection limits were in the range of 0.002−0.005 μg/L for the three compounds. Finally, the newly developed method was evaluated for the analysis of groundwater samples from New York containing...

A cost-effective strategy based on a recently developed ELISA for 4-nitrophenol was used for the characterization of wastewater samples (industrial and/or urban) of the primary sewage effluent and secondary sewage effluent, also called influent and effluent, respectively, of wastewater treatment works (WWTW) using either biological treatment with secondary settlement and/or physicochemical treatment. Two of the WWTW received only domestic wastewaters, whereas three of them received 60−70% of industrial effluents that were mixed with domestic wastewaters before entering WWTW. The 4-nitrophenol ELISA kit was used as a parameter to evaluate the performance of the treatment plants by comparing the ELISA measurements with those routinely used in WWTW, such as total organic carbon and total phenols content using 4-aminoantipyrine. The 4-nitrophenol ELISA gave a positive response to different wastewaters being a useful measurement for the estimation of the performance of the WWTW. The response obtained with 4-ni...

This paper presents a generic protocol for the determination of polar, ionic, and highly water soluble organic pollutants on untreated industrial wastewaters involving the use of two different solid-phase extraction (SPE) methodologies followed by liquid chromatography-mass spectrometry (LC-MS). Untreated industrial wastewaters might contain natural and synthetic dissolved organic compounds with total organic carbon (TOC) values varying between 100 and 3000 mg/L. All polar, ionic and highly water soluble compounds comprising more than 95% of the organic content and with major contribution to the total toxicity of the sample cannot be analyzed by conventional gas chromatography-mass spectrometry (GC-MS), and LC-MS is a good alternative. In this work two extraction procedures were used to obtain fractionated extracts of the nonionic polar compounds: a polymeric Isolute ENV + SPE cartridge for the preconcentration of anionic analytes and a sequential solid-phase extraction (SSPE) method percolating the samples first in octadecylsilica cartridge in series with the polymeric Lichrolut EN cartridge. Average recoveries ranging from 72% to 103% were obtained for a variety of 23 different analytes. Determination of nonionic pollutants was accomplished by reverse-phase liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), while anionic compounds were analyzed by ion pair chromatography-electrospray-mass spectrometry (IP-ESI-MS) and LC-ESI-MS. Thismore » protocol was applied to a pilot survey of textile and tannery wastewaters leading to the identification and quantification of 33 organic pollutants.« less

Propanil and its major degradation product, 3,4-dichloroaniline (DCA), were monitored in surface water and soil samples from two rice fields of the Ebre Delta area (Tarragona, Spain) following agricultural application. On-line solid-phase extraction (SPE) (water) and Soxhlet extraction (soil) followed by liquid chromatography/diode array detection (LC/DAD) were used for the trace determination of both compounds. Unequivocal confirmation/identification was conducted by using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry, LC/APCI-MS (using negative and positive ionization modes). Concentrations of the herbicide propanil in water samples varied from 1.9 to 55.9 μg/L. Propanil degraded very rapidly to DCA, and high concentrations of this product were found, varying from 16.5 to 470 μg/L in water and 119 ± 22 μg/kg in soil samples. No detectable DCA (

Contaminated industrial effluents often contain a variety of organic pollutants which are difficult to analyze by standard GC-MS methods since they often miss the more polar or nonvolatile of these organic compounds. The identification of highly polar analytes by chemical or rapid biological techniques is needed for characterization of the effluents. The present work evaluates the use of enzyme linked immunosorbent assays (ELISA) kits for determining pentachlorophenol, carcinogenic PAHs and BTEX (benzene, toluene, ethylbenzene, and o-, m-, and p-xylene) among the organic analytes present in various industrial effluents from Europe. The analytical protocol applied for the evaluation of the kits was based on the use of ELISA followed by solid-phase extraction (SPE) for the preconcentration of a variety of organic pollutants such as pentachlorophenol, phthalates, and nonylphenol and final determination with LC-MS characterization using an atmospheric pressure chemical ionization (APCI) interface in the positive and negative ionization modes. The developed protocol permitted the unequivocal identification of target analytes such as pentachlorophenol, nonylphenol, dibutylphthalate, dimethylphthalate, bis(2-ethylhexyl)phthalate 2-methylbenzenesulfonamide, and 2,2-dimethylbenzene-sulfonamide present in industrial effluents. The advantages and limitations of the three RaPID-magnetic particle-based ELISA kits applied to the characterization of industrial effluents are also reported.

The determination of Irgarol 1051 in enclosed seawaters from the Mediterranean Spanish Coast was accomplished by a recently developed enzyme-linked immunosorbent assay (ELISA). The results achieved...

The distribution of linear alkylbenzene sulfonates (LAS) and their biodegradation intermediates (SPC) has been studied at a salt marsh of the Bay of Cadiz. The identification and quantification of LAS and SPC was carried out after solid-phase extraction of 250 mL of water samples followed by liquid chromatography with fluorescence, diode array, and ionspray mass spectrometry. The latter procedure permitted the unequivocal confirmation of long-chain SPC, of up to 11 carbon atoms in seawater, and of up to 13 carbon atoms in interstitial water. Some of these compounds have not been described until now in environmental samples. The relative abundance of the SPC found at some of the sampling stations agrees with what would be expected after the occurrence of the first and second β-oxidations of the alkyl chain of the various homologues of commercial LAS. Furthermore, the existence of SPC-C13 in interstitial water proves unequivocally that ω-oxidation occurs in the environment. In general terms, the persistence...

The disappearance of fenitrothion under real environmental conditions was studied. Fenitrothion was applied in the rice crop field of the Ebre Delta (Tarragona, Spain) during July 1995 by helicopter spray ing at a rate of 148 mL/ha Tionfos 50 LE (50% of pure fenitrothion). For monitoring fenitrothion residues in water, two different analytical techniques were used: enzyme-linked immunosorbent assay (ELISA) and automated on-line solid-phase extraction (Prospekt) followed by liquid chromatography/diode array detection (LC/DAD). The unequivocal identification of fenitrothion, fenitrooxon, 3-methyl-4-nitrophenol, and s-methyl isomer of fenitrothion was achieved by liquid chromatography/mass spectrometry (LC/MS) using an atmospheric pressure chemical ionization (APCI) interface in the negative ionization (NI) mode. The residue levels of fenitrothion in rice crop field waters varied from 119−178 μg/L down to 3.8−1.5 μg/L after 48 h of helicopter application. The half-lifetimes t1/2 were calculated by both anal...

The persistence of temephos and its degradation products (temephos sulfoxide, temephos isomer, and temephos sulfoxide isomer) under real environmental conditions was studied. Other breakdown produc...

A novel approach to assess the cross-reactivity of immunoassays in the simultaneous presence of potential cross-reactant analytes was reported. The magnetic particle-based ELISA for chlorpyrifos-ethyl was used as a model assay in various water matrices (distilled, ground, and estuarine) in the presence of other organophosphorus pesticides commonly applied: chlorpyrifos-methyl, pyridafenthion, diazinon, fenitrothion, azinphos-ethyl, dichlorvos, temephos, and fenthion. The interferences were studied at a fixed concentration of 0.5 μg/L chlorpyrifos-ethyl and varying concentrations of the common cross-reactants from 0.05 to 1000 μg/L. The method for determining cross-reactivities gave much lower values (25−50%) as compared to conventional methods. A slight variation (

A magnetic particle-based ELISA for chlorpyrifos-ethyl was investigated in estuarine water matrices, and the results obtained were correlated with automated on-line solid phase extraction (Prospekt) followed by liquid chromatography/diode array detection. The ELISA test was evaluated before and after filtration of the particulate matter present in estuarine water with and without prior acidification. The ELISA assay was used as a first screening method for determining chlorpyrifos-ethyl in a highly contaminated soil spiked at common termicidal application rate (∼1000 mg/kg). The ELISA assay permitted us to distinguish soil contamination of chlorpyrifos-ethyl at 50 mg/kg in conjunction with Soxhlet extraction. Substantial saving time was achieved when compared to conventional methods, which require a cleanup step prior to chromatographic determinations.

The degradation of fenitrothion under real environmental conditions was studied. Fenitrothion was applied in the irrigation ditches of the Ebre Delta (Tarragona, Catalonia) at an estimated concentration of 200 (situation 1) and 20 μg/L (situation 2) in order to eliminate the american crab (Procamburus clarkii). The evolution of the levels of fenitrothion and the formation of transformation products (TPs) were recorded during the 4 days after application. The TPs formed were 3-methyl-4-nitrophenol, fenitrooxon, and 5-methyl isomer of fenitrothion. The concentration of fenitrothion decayed sharply in 2 h with 6% and 0.3% of the initial concentrations in situations 1 and 2, respectively, and reached a steady state within 10 h with a concentration of 4 and 0.01 μg/L, respectively, which was constant for the 4 days the experiment lasted

A multiresidue method for the analysis of 30 pesticides and various transformation products (TPs) has been developed. On-line solid-phase extraction (SPE) using 10 Empore 4.6-mm extraction disks containing C-18 and/ or styrenedivinylbenzene were placed in a disk holder and were used coupled on-line with liquid chromatography (LC) with either UV or postcolumn fluorescence derivatization (EPA method 531.1). The on-line SPE method, using 150 and 10 mL of water for LC-UV and postcolumn fluorescence derivatization, respectively, has been compared with the liquid-liquid extraction (LLE) method involving dichloromethane (NPS method 4) and 1 L of water

C18 Empore extraction disks were used for the isolation and trace enrichment of several pesticides [chlorotriazines (atrazine, simazine, and cyanazine), the atrazine metabolites (deethyl- and deisopropylatrazine), organophosphorus (parathion-ethyl, fenitrothion, fenamiphos, and tetrachlorvinphos), phenylurea (linuron), propioanilide (propanil), and carbamate (carbaryl)] from river water and simulated seawater, at concentration levels of 0.25, 25, and 1000 μg/L.

Water samples were collected from 88 municipal wells throughout Iowa during the summer and were collected monthly at 12 stream sites in eastern Iowa from March to December 1996 to study the occurrence of the sulfonic and oxanilic metabolites of acetochlor, alachlor, and metolachlor. The sulfonic and oxanilic metabolites were present in almost 75% of the groundwater samples and were generally present from 3 to 45 times more frequently than their parent compounds. In groundwater, the median value of the summed concentrations of acetochlor, alachlor, and metolachlor was less than 0.05 μg/L, and the median value of the summed concentrations of the six metabolites was 1.2 μg/L. All surface water samples contained at least one detectable metabolite compound. Individual metabolites were detected from 2 to over 100 times more frequently than the parent compounds. In surface water, the median value of the summed concentrations of the three parent compounds was 0.13 μg/L, and the median value of the summed concentr...