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A sensitive, multi-residue method using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to determine a representative group of 35 analytes, including corrosion inhibitors, pesticides and pharmaceuticals such as analgesic and anti-inflammatory drugs, five iodinated contrast media, β-blockers and some of their metabolites and transformation products in water samples. Few other methods are capable of determining such a broad range of contrast media together with other analytes. We studied the parameters affecting the extraction of the target analytes, including sorbent selection and extraction conditions, their chromatographic separation (mobile phase composition and column) and detection conditions using two ionisation sources: electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI). In order to correct matrix effects, a total of 20 surrogate/internal standards were used. ESI was found to have better sensitivity than APCI. Recoveries ranging from 79 to 134 % for tap water and 66 to 144 % for surface water were obtained. Intra-day precision, calculated as relative standard deviation, was below 34 % for tap water and below 21 % for surface water, groundwater and effluent wastewater. Method quantification limits (MQL) were in the low ng L−1 range, except for the contrast agents iomeprol, amidotrizoic acid and iohexol (22, 25.5 and 17.9 ng L−1, respectively). Finally, the method was applied to the analysis of 56 real water samples as part of the validation procedure. All of the compounds were detected in at least some of the water samples analysed This study was financed by the SpanishMinistry of Science and Innovation through projects CTM2011-28765-C02-02 and CGL2013-48802-C3-2-R, and an FPI grant (Ref. BES-2009-024892) awarded to C. Valls-Cantenys

Simple, precise, and low-cost methods for the simultaneous determination of phenolic endocrine disrupting compounds such as bisphenol A, trichlorophenol, pentachlorophenol, 4-nonylphenol, and 4-octylphenol in water samples were developed. The Direct, in situ derivatization methods are based on polydimethylsiloxane rod extraction followed by liquid desorption and chromatographic analysis by liquid chromatography and diode array detection. Several parameters affecting the extraction and desorption of the phenolic compounds and their acetylated derivates were studied, as well as the chromatographic and detection conditions. For the direct method, determination coefficients (r2) > 0.990 and LODs in the 0.6–2 μg/L range were obtained for all compounds except bisphenol A (9.5 μg/L). With the derivatization-based method, based on in situ acetylation, lower limits of detection (0.3–0.9 μg/L) were obtained for all the compounds with r2 > 0.988 and RSDs in the 2–9% range. The developed methods were applied to the analysis of spiked water samples obtaining recoveries of between 60.2 and 131.7% for the direct method, and of between 76.6 and 108.2% for the derivatization-based method. The results demonstrate the feasibility of using these two methods for determining bisphenol A, trichlorophenol, pentachlorophenol, 4-nonylphenol, and 4-octylphenol in water.

This study presents the development and validation of a new analytical method for the simultaneous determination of fifteen analytes classified as halogenated flame retardants (HFRs) – nine brominated diphenyl ethers (BDEs) and six novel HFRs – in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by gas chromatography coupled to negative chemical ionization-mass spectrometry (GC–NCI-MS). The proposed method is the first one developed for such a broad range of HFRs in aquatic biota, featuring several advantages, including low solvent and sample intake, simplicity of operation, reduced cost and integration of extraction and clean-up into a single step. Under optimal conditions, 0.5 g of freeze-dried sample, 0.5 g of a primary-secondary amine (PSA) as solid support, a sorbent combination of 1.75 g of florisil (deactivated with 5% Milli-Q water), 1.75 g of acidified silica (10% (w/w) H2SO4) and 0.5 g of silica, and 10 mL dichloromethane as elution solvent were used. Standard addition over the extract was required however for the correct quantification due to matrix effects in the GC system, particularly for novel HFRs, that could not be compensated with the internal standards. The method afforded LODs in the range of 0.003–0.07 ng g−1 dry weight (0.0006–0.014 ng g−1 on a wet weight basis, assuming an 80% sample water content), except for decabromodiphenyl ethane (DBDPE) (0.6 ng g−1 dry weight, 0.12 ng g−1 wet weight). The accuracy of the method was evaluated with three different types of spiked mollusk species using surrogate standards and standard addition over the extract for quantification and the recoveries were in the 70–120% range, except for bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) in clam (Ruditapes philippinarum) samples (46% recovery). Moreover, the method was successfully validated with standard reference materials (SRMs) of salmon and mussel tissues for BDEs. Finally, the method was applied to the determination of HFRs in different kind of freeze-dried mollusks: mussel (Mytilus galloprovincialis), cockle (Cerastoderma edule) and clam (R. philippinarum). Raft cultured mussels showed the highest concentrations of HFRs (up to 0.8 ng g−1 wet weight of BDE-209).

An extraction and preconcentration procedure for the determination in water samples of several halogenated flame retardants (FRs), nine brominated diphenyls ethers (BDEs) and seven non-BDE FRs, was developed and validated. The optimised procedure is based on polydimethylsiloxane (PDMS) rods as sorptive extraction material, followed by liquid desorption and gas chromatography coupled to negative chemical ionisation-mass spectrometry (GC-NCI-MS) determination, rendering an efficient and inexpensive method. The final optimised protocol consists of overnight extraction of 100mL of sample solutions containing 40% MeOH and 4% NaCl, followed by a 15-min sonication-assisted desorption with 300μL of ethyl acetate, solvent evaporation and GC-NCI-MS analysis. Under these conditions, extraction efficiencies in the 9 to 70% range were obtained, leading to enrichment factors between 108 and 840, detection limits in the range from 0.4 to 10ngL-1and RSD values in the 2-23% range. After method validation, different real water samples, including river, ria, sea, landfill leachate, influent and effluent wastewater from an urban sewage treatment plant (STP) and effluent wastewater from a textile industry, were analysed. BDE-47, BDE-99, BDE-100 and BDE-197 were detected in wastewater and landfill leachate samples at concentration levels up to 2887ngL-1. Among the non-BDE FRs, bis (2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) was detected in surface water samples (sea, river and ria) between 1.3 and 2.2ngL-1 and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in the landfill leachate (64ngL-1) This work was supported by the Spanish Ministry of Science and Innovation (Ministerio de Ciencia e Innovacion) and FEDER funds, project no. CTQ2009-08377 and CTM2011-28765-C02-02, and Xunta de Galicia, project no.10MDS700006PR. R. Rodil and J.B. Quintana (Ramon y Cajal research program), E. Villaverde-de-Sdaa (FPI grant, ref. BES-2011-047887) and C. Valls-Cantenys (FPI grant, ref. BES-2009-024892) extend their gratitude to the Spanish Ministry of Science and Innovation

Phosphorus is a key nutrient and in natural environments regulates trophic status and consequently water quality. Therefore monitoring of phosphorus content in natural and wastewater is essential. Although several phosphorus species can be found in the environment, the majority of the methods developed are for orthophosphate determination. High performance liquid chromatography (HPLC) coupled with inductively coupled plasma with atomic emission spectroscopy (ICP-AES) has been first used in this study for the speciation of the most common phosphorus oxoanions in aquatic environments: orthophosphate, phosphite, hypophosphite, pyrophosphate and tripolyphosphate. The chromatograms have been obtained by registering the phosphorous 213.618 nm emission intensity variation with time. The pH and the ionic strength of the mobile phase have been the most critical variables of the chromatographic separation. Moreover, methanol addition promotes the elution of the most retained species. Finally, by using ammonium nitrate and a gradient elution, increasing ionic strength and decreasing the pH, the separation has been achieved in 12 min. Limits of detection have been included within the 1–5 mg L −1 range. The developed methodology has been tested with spiked tap water and effluent water of a wastewater treatment plant (WWTP) obtaining recoveries in the range of 91.5–114.1% for a 20 mg P L −1 spike concentration.