Bioconcentration of linear alkylbenzene sulfonates and their degradation intermediates in marine algae

Sorption experiments using different homologues of linear alkylbenzene sulfonate (LAS) and sulfophenylcarboxylic acid (SPC) on several marine microalgae have been carried out. The steady state seems to be reached in the first 4 hours. Longer exposure times lead to biodegradation of the compound and, therefore, to an overestimation of the bioconcentration factor. Sorption coefficients are higher for Nannochloropsis gaditana, for example, 1,293 Lkg(-1) for C11-LAS and 525 Lkg(-1) for C11-SPC versus 727 Lkg(-1) for C11-LAS and 28 Lkg(-1) for C11-SPC for Dunaliella salina. For both algae an increase in the sorption coefficient is observed when the polarity of the compound decreases (C5-SPC相似文献   

Determination of sulfophenylcarboxylic acids in marine samples by solid-phase extraction then high-performance liquid chromatography

An analytical method is presented for the determination of sulfophenylcarboxylic acids (SPC) produced by the biodegradation of linear alkylbenzene sulfonates (LAS) in marine samples. Isolation and concentration of the compounds was by solid-phase extraction. The different factors affecting extraction efficiency packing composition, pH, clean-up, ionic strength, and elution solvents--were studied and optimized. With the proposed method C4-C13SPC and C10-C13 LAS recoveries varied between 65% and 105%, with standard deviations between 0.1 and 5, respectively, for 100-mL samples and 100 microg L(-1) concentrations of each homolog. Detection limits within the range 0.5 g L(-1) (for C4SPC) to 1.0 g L(-1) (for C12SPC) were obtained by liquid chromatography with fluorescence detection. This method is the first to be proposed that enables the simultaneous determination of monocarboxylic SPC (C>3) and LAS homologs in marine samples by a simple, sensitive, and specific method giving high recoveries and reproducibility. SPC with from three to twelve carbon atoms in the carboxyl chain have been found in marine water samples.     

Application of liquid chromatography-electrospray-tandem mass spectrometry for the identification and characterisation of linear alkylbenzene sulfonates and sulfophenyl carboxylates in sludge-amended soils

A novel procedure was developed for the simultaneous determination of linear alkylbenzene sulfonates (LAS) and their major metabolites, sulfophenyl carboxylates (SPC), in sludge-amended soil. After pressurised liquid extraction with methanol/water (90:10) and a clean-up on C18 solid-phase extraction cartridges, final analysis was done by ion-pair liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS). With this method, SPC with 5-13 carbon atoms in the aliphatic side chain were identified for the first time in agricultural soils treated with sewage sludge. Quantification of LAS and SPC in soil from 10 field sites, which differed in the history of sludge application, gave total concentrations of 120-2840 microg kg(-1) for LAS and of 4-220 microg kg(-1) for SPC. The data provided evidence for rapid biodegradation of LAS in the initial phase after sludge amendment with a transitory build-up of high concentrations of, mainly, short-chain SPC. Trace amounts of residual LAS and SPC were detected in soils having received the last sludge treatment 10 days to 4 years prior to sampling.     

Handling of marine and estuarine samples for the determination of linear alkylbenzene sulfonates and sulfophenylcarboxylic acids

Due to the physicochemical properties of linear alkylbenzene sulfonates (LAS), an anionic surfactant, it is difficult to obtain representative samples from sampling sites. Further, the high biodegradability of these compounds makes it necessary to study their biodegradation intermediates, sulfophenylcarboxylic acids (SPC) that do not have a surfactant character and show a different behavior. A procedure for determining and quantifying LAS and SPC in different environmental matrices by Soxhlet and solid-phase extractions and high-performance liquid chromatography is presented. The recoveries varied in the range from 85 to 102% for the water samples, and from 75 to 105% for sediment samples, with a standard deviation of between 1 and 7, and 2 and 11, respectively. Detection limits obtained were in the range from 5 to 10 microg kg(-1) for sediment samples (10 g) and from 0.2 to 0.4 microg l(-1) for water samples (250 ml). The method was applied to the simultaneous determination of LAS (C10-C13) and SPC (C4-C13) homologues in water, sediment and interstitial water collected from different areas of Spain.     

Disulfide symmetric dimers as stable pre-hapten forms for bioconjugation: a strategy to prepare immunoreagents for the detection of sulfophenyl carboxylate residues in environmental samples

A convenient, generic synthesis of bioconjugates from haptens with a thiol group has been established. The corresponding haptens are synthesized as stable symmetric dimmers through a disulfide bond that is reduced immediately before conjugation with the aid of a di(n-butyl)phenylphosphine polystyrene (DBPP) resin. This strategy was used to prepare haptenized biomolecules and to raise antibodies against short-alkyl-chain sulfophenyl carboxylates (X-C(z)-SPCs; X is the position of the benzylic group and z is the alkyl-chain length) formed after degradation of the widely used domestic and industrial linear alkylbenzene sulfonates (LASs) surfactants. Because of the complexity of the LASs technical mixture, homologous and pseudo-heterologous immunization strategies have been studied with the aim of broadening antibody recognition of the SPC family. With this purpose, two types of immunizing haptens have been synthesized and used to prepare bioconjugates and raise antibodies. Type-A bioconjugates (SPC(A)-protein) were prepared by synthesizing type-A haptens as stable symmetric dimers, generically 2,2'-dithiobis[5-{4-(N-ethylsulfamoyl)}phenylalkanoic acids] (X-C(z)-S-SPC). On the other hand, type-B bioconjugates (SPC(B)-protein) were prepared by treating the carboxylic groups of the corresponding 4-sulfophenylalkanoic acids (X-C(z)-SPC) with the amino groups of the lysine residues by using classical carbodiimide procedures. Type-A haptens produced antibodies with a much higher avidity for the target analyte. Under competitive immunochemical configurations (As112/2-C(5)-ovalbumin), these antibodies can reach a limit of detection (LOD) of 40 ng L(-1) with an IC(50) value of 200 ng L(-1) for 3-C(6)-SPC, which opens up the possibility of trace contamination of edible waters by surfactants with 3-C(6)-SPC as a marker of LAS pollution. A comparative study of the properties of the three families of polyclonal antibodies produced revealed that antibodies raised through pseudo-heterologous immunization strategies produced antibodies with a broader specificity versus the SPC family. These results indicate that this approach could be useful in avoiding synthetic difficulties associated with preparing haptens that preserve all the most important chemical functionalities of the molecule.     

Assessment of the hemolysis and endothelial cell cytotoxicity induced by residual linear alkylbenzene sulfonates on pharmaceutical rubber stoppers based on HPLC‐ESI‐MS

This study was designed to develop a high‐performance liquid chromatographic–electrospray ionization–mass spectrometry (HPLC‐ESI‐MS) method for quantitative determination of residual surfactant linear alkylbenzene sulfonate (LAS) compounds on pharmaceutical rubber stoppers. An HPLC‐ESI‐MS method was developed for separation and determination of five LAS homologs (C10–C14) under gradient conditions using methanol and ammonium acetate as mobile phases. Hemolysis activity of residual LAS compounds was analyzed by spectrophotometry. Expression of interleukin (IL)‐6 and tumor necrosis factor (TNF)‐α in human umbilical vein endothelial cells (HUVECs) after LAS compound treatment was examined by enzyme‐linked sorbent assay. LAS compounds were well separated and determined by the established gradient conditions. The linear range was 0.05–8 µg/mL with correlation coefficients ≥0.997. Recoveries were from 73 to 134% and the relative standard deviation was <13.7%. There was a correlation between hemolysis rate and LAS compounds concentration when it was ≥0.8 µg/cm². LAS compounds decreased the viability of HUVECs and promoted the production of IL‐6 and TNF‐α. The developed analytical method was successful for quantitative determination of residual LAS compounds on pharmaceutical rubber stoppers and it is important to monitor and control the amount of LAS compounds on rubber stoppers. Copyright © 2015 John Wiley & Sons, Ltd.     

Ion-pair extraction and GC-MS determination of linear alkylbenzene sulphonates in aqueous environmental samples

A GC-MS method was developed for the determination of linear alkylbenzene sulphonates (LAS) and sulphophenylcarboxylic acids (SPC) in aqueous environmental samples. LAS and SPC were isolated from aqueous samples using methylene green (MG) as ion-pair reagent and derivatised with diazomethane for their chromatographic analysis. LAS and SPC were then analysed with GC-MS in EI mode as their methyl esters. The method eliminates positive and negative interferences found by the methylene blue method and considered to be selective and sensitive for the determination of LAS and SPC in aqueous samples. The recovery of LAS was 98% with a relative standard deviation (R.S.D.) of 2.0% and the detection limit obtained from calculations by using GC-MS results based on S/N:3 was lower than 10 ppb. Obtained results revealed that the method can also be employed in the analysis of organic compounds bearing sulphate and sulphonate groups.     

LC-MS determination of linear alkylbenzene sulfonates and their carboxylic degradation products in influent and effluent water samples and sludges from sewage-treatment plants

Linear alkylbenzene sulfonates (LAS) have been determined in samples of the influent and the effluent, and in the sludge, from sewage-treatment plants (STP). LAS and sulfophenyl carboxylate compounds (SPC) were isolated by solid-phase extraction (SPE) with the polymeric phase Isolute ENV, then determined by liquid chromatography-electrospray mass spectrometry (LC-ESI-MS). The method enabled unequivocal identification of C10-C13 LAS by monitoring the ion at m/z 183 and the base peak corresponding to the [M-H]- ion. Average recoveries varied from 77-93% and the linear range of the method varied from 0.2 to 10 microg L(-1), with a limit of detection ranging from 10 ng L(-1) to 1.5 microg L(-1) when 200 mL waste water were preconcentrated. For sewage sludge, recoveries varied from 58 to 90% and the linear range was between 0.2 and 100 microg L(-1), with a detection limit ranging from 0.4 to 120 microg kg(-1) when 2.5 g sewage sludge was extracted. Unequivocal identification and determination of some metabolites of the LAS, the sulfophenyl carboxylate compounds (SPC), was achieved by monitoring [M-H]- ions.     

Determination of Sulfophenyl Carboxylic Acids in Agricultural Groundwater Samples by Liquid Chromatography with Fluorescence Detection

Abstract

We have developed an analytical method to determine six sulfophenyl carboxylic acids (SPC) in agricultural groundwater samples. It involves a solid-phase extraction (SPE) procedure and subsequent separation and determination using liquid chromatography with fluorescence detection (LC–FD).The quantification limits ranged between 0.7 and 1.2 ng ml^?1. The proposed method was proved satisfactorily for the detection and determination of these compounds in groundwater samples during a study into the biodegradation of linear alkylbenzene sulfonates (LAS) in an agricultural soil sampled from the irrigated plain to the west of Granada (Spain).     

Determination of linear alkylbenzene sulfonates and their polar carboxylic degradation products in sewage treatment plants by automated solid-phase extraction followed by capillary electrophoresis-mass spectrometry.

Linear alkylbenzene sulfonates (LAS) were determined by solid-phase extraction (SPE), followed by capillary electrophoresis and mass spectrometry detection (CE-MS). The linear range of the proposed method varied from 33 to 316 and from 215 to 2057 micrograms L-1, depending on the compound, with limits of detection ranging from 4.4 to 23 micrograms L-1 when 200 ml of wastewater were preconcentrated. The analysis and confirmation of the polar carboxylic metabolites of LAS, the sulfophenyl carboxylic acids (SPC) was also achieved, and their presence was detected in both, influent and effluents of the sewage treatment plant (STP). [M - H]- ions were used for CE-MS confirmation and quantification. CE-MS diagnostic ions were the same ones used in LC-electrospray (ESI)-MS and corresponded to m/z 297, 311, 325 and 339 for C10LAS, C11LAS, C12LAS and C13LAS, respectively. For SPC identification, diagnostic ions corresponded to m/z 215 to 369 (with 14 mass unit steps) for C2 to C13SPC, respectively. LAS were determined in wastewater samples of the influent and effluent of three sewage treatment plants (STP), two of them using biological treatment with secondary settlement and receiving mainly domestic wastewater whereas one of the plants was operated with physiochemical treatment and received mainly industrial wastewater. The concentration levels of total LAS varied from 1000 to 1900 micrograms L-1 in the influents of STP, whereas in the effluents the concentrations varied from 125 to 360 micrograms L-1.     

Metabolites from the biodegradation of 1,6‐hexanediol dibenzoate,a potential green plasticizer,by Rhodococcus rhodochrous

Metabolites from the biodegradation of a potential plasticizer 1,6‐hexanediol dibenzoate in the presence of n‐hexadecane as a co‐substrate by the common soil organism Rhodococcus rhodochrous were identified using GC/MS and Fourier transform mass spectroscopy (FTMS) techniques. Trimethylsilylation of compounds from the biodegradation broth permitted detection of the following metabolites: 1‐hexadecyl benzoate, 6‐benzoyloxyhexanoic acid, 4‐benzoyloxybutanoic acid, 6‐benzoyloxyhexan‐1‐ol and benzoic acid. The presence of these metabolites was confirmed by repeating the biodegradation with 1,6‐hexanediol di[²H₅]benzoate, by measurement of their exact masses in FTMS and by comparison with available authentic materials. The results show that biodegradation of 1,6‐hexanediol dibenzoate by R. rhodochrous does not lead to the accumulation of persistent metabolites as has been reported for commercial dibenzoate plasticizers. Copyright © 2009 John Wiley & Sons, Ltd.     

Testing organic solvents for the extraction from fish of sulfophenylcarboxylic acids, prior to determination by liquid chromatography-mass spectrometry

The present paper describes the use of different solvent mixtures to extract from fish various sulfophenylcarboxylic acids (SPCs of C₆ to C₁₃), and their originating compounds, linear alkylbenzene sulfonates (LAS of C₁₀ to C₁₃). The analytical method utilized involves pressurized liquid extraction, followed by preconcentration of the samples, purification by solid-phase extraction, and finally identification and quantification of the target compounds by high-performance liquid chromatography-mass spectrometry using a system equipped with an electrospray interface operating in negative ion mode. The SPCs and LAS were extracted from spiked fish first with hexane to remove interference from fats, then with different mixtures of solvents: dichloromethane followed by methanol; 50:50 dichloromethane-methanol; and 30:70 dichloromethane-methanol. The LAS recoveries obtained with these three extraction options were high (between 68.5 and 80.8%); however, owing to the low percentages obtained for SPC homologues (13.5, 13.1, and 15.9%, respectively), another extraction procedure with methanol was developed in order to increase these recoveries. The percentage of recovery for total SPCs with the methanolic extraction was higher (90.1%), with a standard deviation of 9.9, and the LAS recoveries also increased (99.9%). Detection limits were between 1 and 22 ng g^?1 for LAS, and between 1 and 58 ng g^?1 for SPCs. Quantitation limits were between 4 and 73 ng g^?1 for LAS, and between 2 and 193 ng g^?1 for SPCs. This method has been applied to measure the biotransformation of 2ØC₁₀ LAS (where Ø is a sulfophenyl group) in fish exposed in a flow-through system, and enabled the separation and identification of SPCs from 5ØC₆ to 9ØC₁₀.     

Determination of Las in Wastewater Treatment Plants: Comparative Study Between Conventional Biodegradation Testing and an Alternative Photo-Oxidation Method

Abstract

The aim of this paper was to study the reaction pathway of the biodegradation and photodegradation of Linear Alkylbenzene Sulphonates (LAS), and to propose an analytical method, faster and more reliable, to predict the evolution of LAS in a sewage treatment plant. For this purpose, a 20mgL^?1 LAS solution was treated on the one hand by a conventional biodegradation method using microorganisms, taken directly from aeration tanks of a sludge treatment plant, and on the other hand by UV radiation. This second method allows a rapid determination of LAS and its by-products by means of a UV signal treatment. This alternative method seems thus to be more suitable for on-line analysis.     

Tracing of surfactants in the biological wastewater treatment process and the identification of their metabolites by flow injection-mass spectrometry and liquid chromatography-mass spectrometry and -tandem mass spectrometry

Results of aerobic biodegradation of alkyl ethoxylates (AEOs), of nonylphenol polyethoxylates (NPEOs), and of NPEO derivatives (sulfonates and sulfates), as well as anaerobic NPEO biodegradation monitored by flow injection analysis (FIA) or liquid chromatographic separation (LC) in combination with mass (MS) and tandem mass spectrometry (MS-MS) are presented. The application of visual pattern recognition in the FIA-MS mode showed quite different degradation pathways for C13-AEOs, so that aldehyde compounds as metabolites could be confirmed by collision-induced dissociation for the first time. Methyl ethers of AEO compounds were found to be persistent under aerobic conditions, while NPEO degradation resulted in nonylphenol polyether carboxylates. FIA- and LC-MS proved that NPEO derivatives used as anionic surfactants were either non-biodegradable (nonylphenol diethoxy sulfonate) or were primarily degraded (nonylphenol polyethoxy sulfates) into compounds of the same molar masses yet of different retention behaviour. Anaerobic degradation of NPEOs led to the generation of nonylphenols, which was confirmed by GC-MS.     

Multi-residue method for the analysis of synthetic surfactants and their degradation metabolites in aquatic systems by liquid chromatography-time-of-flight-mass spectrometry

Synthetic surfactants are economically important chemicals, as they are widely used in household cleaning detergents, textiles, paints, polymers and personal care products. In this work we have developed a method capable of the isolation and analysis of the most widely used surfactants (linear alkylbenzene sulfonates, LAS, nonylphenol ethoxylates, NPEO, and alcohol ethoxylates, AEO) and their main degradation products (sulfophenyl carboxylic acids, SPC, nonylphenol ethoxycarboxylates, NPEC, and polyethylene glycols, PEG) in aqueous and solid environmental matrices. First, analytes were extracted by ultrasonic extraction from sediments and suspended solids using methanol at 50°C as solvent and 3 cycles (30 min per cycle). Clean-up and pre-concentration of the extracts and water samples were carried out by solid-phase extraction (SPE), using Oasis HLB cartridges. Recoveries were generally about 80% for most compounds. Identification and quantification of target compounds were performed by liquid chromatography-time-of-flight-mass spectrometry (LC-ToF-MS), which has been much less used in the field of environmental analysis than other MS techniques. Examples which illustrate the possible advantages of this technique for multi-analyte analysis of target and non-target contaminants in environmental samples are provided. Finally, the methodology developed here was validated by measuring the concentration of surfactants and their metabolites in selected marine sediment and seawater samples collected in Long Island Sound (NY), and in influent and effluent wastewater from Stony Brook treatment plant (NY). This paper presents some of the first data relative to the occurrence of PEG in the environment, especially in sediments where concentrations were generally higher (up to 1490 μg/kg) than those for other classes of targeted surfactants and their metabolites.     

Predicting the biodegradation products of perfluorinated chemicals using CATABOL

Perfluorinated chemicals (PFCs) form a special category of organofluorine compounds with particularly useful and unique properties. Their large use over the past decades increased the interest in the study of their environmental fate. Fluorocarbons may have direct or indirect environmental impact through the products of their decomposition in the environment. It is a common knowledge that biodegradation is restricted within non-perfluorinated part of molecules: however, a number of studies showed that defluorination can readily occur during biotransformation. To evaluate the fate of PFCs in the environment a set of principal transformations was developed and implemented in the simulator of microbial degradation using the catabolite software engine (CATABOL). The simulator was used to generate metabolic pathways for 171 perfluorinated substances on Canada's domestic substances list. It was found that although the extent of biodegradation of parent compounds could reach 60%, persistent metabolites could be formed in significant quantities. During the microbial degradation a trend was observed where PFCs are transformed to more bioaccumulative and more toxic products. Perfluorooctanoic acid and perfluorooctanesulfonate were predicted to be the persistent biodegradation products of 17 and 27% of the perfluorinated sulphonic acid and carboxylic acid containing compounds, respectively.     

固相微萃取与色谱联用方法分析水中12种有机氯化合物

运用顶空固相微萃取与色谱闻用方法（ＨＳ－ＳＰＭＥ－ＧＣ）对水中的残留有机氯化合物进行了分析。对影响ＨＳ－ＳＰＭＥ－ＧＣ分析灵敏度的各种实验因素如涂层种类,萃取温度、平衡时间,离子浓度等进行了讨论并将该方法与固相萃取法（ＳＰＥ）,液液萃取法（ＬＬＥ）作了对比,同时考察了常见环境共存污染物直链烷基苯磺酸钠（ＬＡＳ）对几种方法的影响。     

Extraction and determination of linear alkylbenzenesulfonate detergents from the aquatic environment using a membrane disk and gas chromatography

Levels of linear alkylbenzenesulfonate (LAS) detergents have been measured in Anzali lagoon water sampled at fourteen stations. All samples were extracted with octadecyl-bonded silica membrane disks. Extraction efficiency, maximum capacity, and the effect of the solvent used to extract the LAS from the membrane disks were evaluated. Extraction efficiencies > 95% were obtained by elution of the disks with minimal amounts of solvent. It was demonstrated that membrane disk extraction introduced less error into analytical results than liquid – liquid extraction. Quantitative determination of total LAS levels and measurement of the distribution of LAS homologs with C₁₀? C₁₃ alkyl chains were performed by high resolution gas chromatography with flame ionization detection after derivatization of the detergents with sulfonyl chloride. The total level of LAS ranged from 0.01 to 0.89 ppm.     

New sample treatment for determination of linear alkylbenzene sulfonate (LAS) in agricultural soils by liquid chromatography with fluorescence detection

A new sample-treatment procedure has been developed for determination of total linear alkylbenzene sulfonate (LAS), i.e. homologues and isomers, in agricultural soil. The procedure involves two steps, ultrasound-assisted extraction of LAS from the samples with methanol then clean-up of the methanolic extracts and preconcentration of the LAS by solid-phase extraction on two adsorbent cartridges (SAX and C₁₈). The ultrasound-assisted procedure reduces extraction time (10 min in contrast with 6–12 h for conventional Soxhlet extraction) and requires only small volumes of organic solvent. The effect of different variables interacting in the ultrasound-assisted extraction process was studied. Finally, separation and quantification of the homologues and isomers of LAS was performed by liquid chromatography with fluorescence detection (LC?FD). 2-Octylbenzenesulfonic acid sodium salt (Na-2ØC₈-LAS) was used as internal standard. The proposed method was satisfactorily used for determination of LAS in agricultural soil samples from the fertile plain of Granada (Spain).

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Figure LAS treatment, a field experience

     

Determination of photodegradation and ozonation by products of linear alkylbenzene sulfonates by liquid chromatography and ion chromatography under controlled laboratory experiments

A Suntest solar simulator with arc xenon lamp was used to irradiate pure linear alkylbenzene sulfonates (LAS) standard and some commercial LAS solutions. The ozonation treatment was carried out in a pilot plant air-lift type reactor. Kinetic degradation curves were obtained showing an apparent first order reaction in both cases. Extraction and preconcentration of samples was carried out by off-line SPE using polymeric an RP-18 cartridges with recoveries varying from 77 to 93% for the LAS compounds. For LC chromatographic elution of LAS and degradation products an ion pair based on 5 mM triethylamine and 5 nM acetic acid had to the acetonitrile-water or methanol-water mobile phases. Fluorescence detection was achieved at 225 and 295 nm as excitation and emission radiation wavelength, respectively. Degradation by products were identified by liquid chromatography electrospray mass spectrometry detection (LC-ESI-MS). Ion chromatography (IC) was used to analyze refractory species such as oxalate, formate and acetate ions which were present in the treated solution even after 3 h of ozone treatment. The LAS mixture was almost totally degraded in less than 20 min using O₃/H₂O₂, the reaction being faster than in the case of catalyzed photodecomposition. TOC removal reached 84% after 3 h of ozonation process.