Montserrat Castillo

Persistence of selected pesticides and their phenolic transformation products in natural waters using off-line liquid solid extraction followed by liquid chromatographic techniques

The degradation of three organophosphorus pesticides with phenolic type structure (fenitrothion, ethyl-parathion, methylparathion) and pentachlorophenol in natural waters from Porto (Portugal) was studied. Three different types of natural waters (river water, estuarine water and ground water) were spiked with ethyl-parathion, methyl-parathion, fenitrothion and pentachlorophenol at 40 μg/l level and were exposed outdoor to ambient sunlight and temperature in natural conditions at the Faculty of Pharmacy of Porto during a period up to 7 weeks. Water samples were placed in 1 1 Pyrex flasks, properly closed. The samples were exposed day and night at these conditions during May and June 1996, the outside temperature being 22 °C with 5.5 h of sunlight exposition per day on average during the period studied. In order to monitor the degradation process, 100 ml of water was preconcentrated periodically by means of liquid solid extraction (LSE) using the polymeric sorbent Lichrolut EN from Merck (Darmstadt, Germany) and the extract was determined by liquid chromatography with diode array detection (LC-DAD). The use of LC coupled with mass spectrometry detection (LC-APcI-MS) permitted the unequivocal identification of various degradation products (4-nitrophenol, 3-methyl-4-nitrophenol, paraoxon ethyl, paroxon methyl, fenitrooxon and S-methylisomer of fenitrothion). Half-life for methyl-parathion was of 3 days in ground water and 4 days in both estuarine and river water; half-life for ethyl-parathion was of 2 days in ground and estuarine water and 3 days in river water; values of 1 day and less than 2 h were obtained for fenitrothion and pentachlorophenol, respectively, in all types of water. All transformation products resulted to be more stable than parent compounds except in ground water conditions. Half-lives of 5 and 4 days were calculated for 4-nitrophenol and paraoxon ethyl, respectively, in estuarine and river water. Values of 3 and 4 days were obtained for 3-methyl-4-nitrophenol in estuarine and river water, respectively.

ANALYSIS OF INDUSTRIAL EFFLUENTS TO DETERMINE ENDOCRINE-DISRUPTING CHEMICALS

Abstract Contaminated industrial effluents often contain a variety of organic pollutants that can disturb the development of the endocrine system and the organs that respond to endocrine signals in organisms. Total characterisation of the effluents to detect all these potential endocrine disruptors by standard GC-MS methods is difficult since this technique often misses the more polar or non-volatile fraction of these organic compounds. The wide spectrum of endocrine-toxic substances and their low concentrations require powerful analytical approaches like LC-MS for their identification. Furthermore, the methods for the detection of endocrine effects developed up to now do not show all the possible oestrogenic effects and results of the different tests are not comparable to one another. Therefore, further ecotoxicological research should be carried out so that new strategies can be proposed. In this article, an overview of the analytical methods for determining organic contaminants in industrial effluents and tests for the identification of endocrine disruptors and their effects is presented.

Toxicity assessment of organic pollution in wastewaters using a bacterial biosensor

Abstract A cost-effective strategy using an amperometric biosensor with Escherichia coli that provides a rapid toxicity determination of wastewaters is described. This Cellsense biosensor system comprises a biological component (E. coli) immobilized in intimate contact with a transducer which converts the biochemical signal into a quantifiable electrical signal. The electrical signal can subsequently be amplified, stored and displayed. This work using a whole bacterial biosensor system studied the E. coli responses to commonly detected compounds in textile and tannery wastewaters, such as phenolic compounds, non-ionic surfactants, and benzene sulfonate compounds. Chemical analysis was performed by sequential solid-phase extraction (SSPE) followed by liquid chromatography–mass spectrometry (LC–MS). The 50% effective concentrations (EC50) values were determined for every standard substance and were converted to toxicity units (TU). The Cellsense system was applied to real-world environmental samples of influent and effluent wastewater treatment works (WWTW) in Catalonia (Spain), with one WWTW receiving industrial tannery wastes, and untreated textile wastewater from Porto (Portugal). The toxicity units were also calculated for the samples giving positive responses to the toxicity to the Cellsense system and permitted to establish the pollutants responsible of the observed toxicity.

Determination of non-ionic surfactants and polar degradation products in influent and effluent water samples and sludges of sewage treatment plants by a generic solid-phase extraction protocol

Non-ionic polyethoxylated surfactants (nonylphenol polyethoxylates, alcohol polyethoxylates), their breakdown products (polyethylene glycol, polyethoxylated nonylphenol carboxylates and polyethoxylated alcohol carboxylates) and other compounds were identified and measured in various waste-water treatment samples (influent, effluent and sludge). A generic protocol involving the use of sequential solid-phase extraction (SSPE) with octadecylsilica and styrene-divinylbenzene cartridges in series and differential elution was used. Fractionated extracts were analyzed by liquid chromatography-mass spectrometry (LC-MS) using atmospheric pressure chemical ionization (APCI) in the positive and negative ionization modes. For sewage treatment plant (STP) sludge, the extraction protocol involved lyophilization of the sludge followed by sonication with MeOH-CH2Cl2 (7 + 3) and final clean-up using the SSPE protocol. Limits of detection for target analytes ranging from 1.1 to 4.1 micrograms L-1 for water samples and from 0.11 to 0.28 mg kg-1 for sludge were achieved. The results obtained demonstrated the inefficient removal of the target analytes in physico-chemical STPs whereas their elimination factors in STPs with biological treatment reached average values of 77, 92 and 98% for alcohol polyethoxylates, nonylphenol polyethoxylates (NPEOs) and polyethylene glycols (PEGs), respectively. Quantitative elimination of coconut fatty acid diethanolamide (CDEA) surfactants in the activated sludge process occurred. In contrast, total removal of NPEOs led to the formation of persistent and toxic metabolites such as nonylphenol which was present in treated effluent as well as in sludge samples with average concentrations ranging from 15.0 to 251.2 micrograms L-1 and from 13.5 to 74.2 mg kg-1, respectively. Polyethoxylated carboxylates and short chain NPEOs were also detected at similar levels in the effluents and sludges. In addition, a linear correlation between the total phenolic concentration (Total Ph) measured by the 4-aminoantipyrine method and the total concentration of nonylphenolic compounds (Total NP) measured by SSPE-LC-APCI-MS was observed.

Characterization of organic pollutants in industrial effluents by high-temperature gas chromatography-mass spectrometry

Abstract The characterization of complex mixtures of organic contaminants present in industrial effluents is a well-known problem. The determination of individual target analytes depends very much on the analytical method used. In this article, the possibilities of using high-temperature gas chromatography–mass spectrometry (HT-GC–MS) are explored. In HT-GC–MS non-polar and medium-polarity phases can be operated at temperatures up to 370–420°C, allowing the analysis of high-molecular-weight compounds. So far, the applications of HT-GC have included the analysis of hydrocarbons up to C-100, lipids, sugars, and polyglycerols, but no data have been reported on the characterization of organic pollutants present in industrial effluents. The general sample handling approach reported here is based either on a sequential solid-phase extraction (SSPE) procedure, with a change of solvent composition in the elution from two different cartridges (C18 and Lichrolut EN), or on a toxicological fractionation. Effluent samples from tanneries, petrochemical plants, and textile industries are characterized, and the levels of the main organic pollutants identified are indicated. More than 50 compounds, including n-alkanes, phthalates, esters, acids, and phenols, were identified in the effluents studied.

Characterization of organic pollutants in industrial effluents using liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry

Contaminated industrial effluents often contain a variety of organic pollutants which are difficult to analyse by standard GC-MS methods since this technique often misses the more polar or non-volatile fraction of these organic compounds. In the present work a method for the characterization of complex mixtures of organic contaminants present in various industrial effluents is proposed. The protocol consists of setting-up a methodology based on solid phase extraction (SPE) using an Automated Sample Preparation with Extraction Columns system (ASPEC XL) and Lichrolut EN sorbent material for preconcentrating 300-500 ml of water volumes spiked with a variety of pollutants: phenolic compounds, benzophenone, isothiocyanate-cyclohexane, ethylbenzoate, 1 -methyl-2-pyrrolidinone, 2-methylbenzenesulphonamide, benzidines, acridine, 1,1,3,3-tetramethyl-2-thiourea, 2,2-dimethyl-1,3-propanediol, phosphates, phthalates and non-ionic detergents characterized by LC-MS using atmospheric pressure chemical ionization in the positive and negative ion modes. The developed protocol permitted unequivocal identification of target analytes such as pentachlorophenol, tributyl pbosphate, 4-nonylphenol, dibutylphthalate, dimethylphthalate, bis(2-ethylhexyl)phthalate, isothiocyanate-cydohexane, ethylbenzoate, 2-methylbenzene-sulphonamide, tetramethyl-thiourea, 2,2-dimethyl-1,3-propanediol and 1-methyl-2-pyrrolidinone at concentration levels varying from 0.16 to 54.4 μg l -1 .

Identification of cytotoxic compounds in European wastewaters during a field experiment

Abstract Two short term bioluminescence inhibition assays based on Vibrio fischeri (Microtox ® and ToxAlert ® 10 tests) were used for the estimation of the cytotoxicity of several European wastewaters from Germany, Spain and Sweden during a field experiment carried out in Berlin (Germany) organised by the Environment and Climate program of the European Commission. The various effluents, freshly collected and transported immediately to Berlin, were tested for their cytotoxic potential and were characterised by an analytical protocol involving the use of sequential solid phase extraction (SSPE) followed by liquid chromatography-mass spectrometry (LC-MS). The bioluminescence tests showed a relatively high sensitivity concerning cytotoxic effects. Besides the wastewater samples of a cement industry (K1 to K3), the effluents of all industrial plants demonstrated a high cytotoxic impact on test bacteria. The highest toxicity was observed in the tannery raw effluent from Sweden and Spain (SW1 and BAR1, respectively). Cytotoxicity was investigated in different wastewater samples of two sewage treatment plants (STP) receiving the raw tannery wastewaters of Sweden and Spain mixed with domestic wastewaters and industrial effluents of a German manufacturing plant. A substantial decrease on the inhibition from 70–80% down to 15–20% was observed when analysing the untreated influent versus the treated effluent of both STPs, respectively. In addition, genotoxicity with the umu-assay (DIN 38415T3, ISO FIS/DIS13829) was also performed and high genotoxicity was observed when analysing the same untreated wastewater samples that showed the highest bioluminescence inhibition with V. fischeri with a good correlation between both tests. The analytical protocol applied for the evaluation of the toxicity tests involves the use of SSPE using C18 and polymeric cartridges (Isolute ENV+) followed by ion pair-electrospray-mass spectrometry (IP-ESI-MS) and by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS). By this protocol different analytes including non-ionic (polyethoxylates) surfactants, ionic (linear alkyl benzene-sulfonates) surfactants, phenols, benzene-sulfonates and naphthalene-sulfonates were determined. Combination of this previously developed methodology with toxicity measurements allowed to detect different groups of pollutants responsible for the toxicity of the studied wastewaters. Evidence of the existence of a correlation between the presence of LAS and cytotoxic effects was observed in those samples where these analytes were major pollutants. Synergetic effects were observed for naphthalene-sulfonate derivatives whose presence enhanced the cytotoxicity of other pollutants present in the sample.

Identification of surfactant degradation productsas toxic organic compounds present in sewage sludge

A cost-effective strategy combining chemical analysis and bioassays for the identification of polar toxic compounds in sewage sludge is reported. ToxAlert 100 bioluminescence inhibition assay was used in combination with chemical analysis involving extraction, clean-up, chromatographic separation and mass spectrometry detection. This methodology was applied to real samples of sludge from three wastewater treatment plants (WWTP) located in Catalonia (Spain) during a 3 month period. In the first step, sewage sludge was lyophilized, treated by sonication with a mixture of methanol and chloroform and finally cleaned up using a sequential solid phase extraction (SSPE) with an octadecylsilica cartridge (C18) in series with a polymeric Lichrolut EN cartridge (Lic EN). In the second step, the toxicity of each fraction of the sludge sample was investigated using the ToxAlert 100. The unequivocal identification and quantification of polar organic cytotoxic substances present in the fractionated extracts were determined by liquid chromatography-mass spectrometry (LC-MS). Major toxic compounds identified were: non-ionic polyethoxylated surfactants (nonylphenol polyethoxylates, alcohol polyethoxylates), their intermediates (polyethylene glycol polyethoxylated, nonylphenol carboxylates and polyethoxylated alcohol carboxylates), linear alkylbenzenesulfonates and heavy metals. The toxic response (in terms of bioluminescence inhibition using ToxAlert 100), defined by the 50% effective concentration (EC50), and the toxicity units (TU) for every standard non-ionic surfactant were calculated. The results provided the identification of polar cytotoxic compounds as well as the evaluation of their contribution to the total toxicity observed in sewage sludge.

Chapter 12 Determination of organic pollutants in industrial wastewater effluents

Publisher Summary This chapter describes the methodology for the analysis of target and nontarget compounds present in wastewaters, such as untreated or treated industrial effluents and leachates from landfills. It presents sample preparation strategy, separation and identification methods, and nonconventional analytical techniques, such as toxicity-based or biological methods. The chapter also discusses the applications of the techniques developed for the analysis of wastewaters. A good performance of alternative extraction methods, such as solid phase extraction (SPE) or solid phase microextraction (SPME) has permitted a great increase in its use and acceptance; however, there is the need of combining chemical analysis based on the extraction and fractionation of the extracts followed by liquid chromatography-mass spectrometry (LC-MS) or gas chromatography-mass spectrometry (GC-MS) with toxicity evaluation with a battery of reliable tests. The main goal in wastewater analysis is a complete characterization of the discharges to identify total organic carbon (TOC) that contributes to the toxicity of the sample. Therefore, new analytical devices or improvements of established techniques will contribute to increase the knowledge on the organic content of the sample. Combination of LC-MS-MS and synthesis of authentic standards to unequivocally identify unknowns is continuously needed.