Search

The occurrence of sweeteners in the environment has become a matter of concern due to the possibility of adverse effects on human health and wildlife species. One of the routes by which sweeteners enter the environment is through sewage sludge. Therefore, a method was developed with a selective-pressurized liquid extraction (S-PLE) followed by liquid chromatography-tandem mass spectrometry for the simultaneous determination of eight sweeteners in sewage sludge. The chromatographic separation was achieved in less than ten minutes using an amide polar-embedded reversed-phase column. Due to the high matrix effect present in the sample, an extensive study was conducted in order to overcome this issue, with C18 in-cell and solid-phase extraction (Oasis HLB) as a clean-up method. S-PLE/SPE recoveries at two levels of concentration (50μg/kg and 1000μg/kg in dry weight (d.w.), n=5) were higher than 61%. Repeatability and reproducibility at the same concentrations (%RSD, n=5) were lower than 11% and 16%, respectively. The limits of detection were 10μg/kg (d.w) for all compounds, except for cyclamate (5μg/kg (d.w.)). The method was successfully applied to sewage sludge samples from three sewage treatment plants located in Catalonia (Spain). Of the eight compounds, five were determined in all of the samples analysed, with acesulfame and saccharine being recorded at the highest concentrations of up to 481μg/kg and 591μg/kg (d.w.), respectively., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 μg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9-18.9 μg/kg dry weight)., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction method followed by liquid chromatography-(Orbitrap) high resolution mass spectrometry was developed for the simultaneous determination of five benzotriazole, four benzothiazole and five benzenesulfonamide derivates in sewage sludge. While the method was being developed, several buffers and dispersive solid-phase extraction clean-up (dSPE) sorbents were tested. Citrate buffer and Z-sep+ (zirconium-based sorbent) were the most effective extraction buffer and dSPE clean-up material. The absolute recoveries were higher than 80% for all compounds (100ng/g (d.w.)) and the matrix effect was less than -20% for most compounds. The limits of detection were between 0.5 and 10ng/g (d.w.) and the limits of quantification (LOQ) were between 1 and 25ng/g (d.w.). Repeatability and reproducibility were lower than 15% (%RSD, n=5). Several sludge samples from five sewage treatment plants in Catalonia were analysed and the most abundant compounds were 2-hydroxybenzothiazole (

For the first time, headspace solid-phase microextraction (HS-SPME) has shown to be a powerful technique to extract macrocyclic musk fragrances directly from sewage sludge. It avoids the need to use additional extraction/preconcentration techniques or clean-up procedure and facilitates the automation of the method. Thus, a simple and fully automated method based on HS-SPME and GC-MS has been developed which allows the determination of eight macrocyclic musk fragrances at ngg(-1) (d.w.) levels. The optimal HS-SPME conditions were achieved when a PDMS/DVB 65μm fibre was exposed for 45min in the headspace of 0.25g sewage sludge samples mixed with 0.5mL of water stirred at 750rpm at 80°C. Optimal desorption conditions were found to be 250°C for 3min. Method detection limits were found in the low pgg(-1) range between 10pgg(-1) (d.w.) and 25pgg(-1) (d.w.) depending on the target analytes. In addition, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in sewage sludge with relative standard deviations varying between 1% to 9% and 6% to 15% respectively (n=5, 1000pgg(-1) d.w.). The applicability of the method was tested with sewage sludge from three urban sewage treatment plants (STPs). The analysis revealed the presence of the macrocyclic musks studied in several samples, with concentrations ranging between below MQL (method quantification limit) and 0.89ngg(-1) (d.w.)., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A method for the quantitative determination of ten musk fragrances extensively used in personal care products from sewage sludge was developed by using a pressurized liquid extraction (PLE) followed by an automated ionic liquid-based headspace single-drop microextraction and gas chromatography-tandem mass spectrometry. The influence of main factors on the efficiency of PLE was studied. For all musks, the highest recovery values were achieved using 1 g of pretreated sewage sludge, H(2) O/methanol (1:1) as an extraction solvent, a temperature of 80°C, a pressure of 1500 psi, an extraction time of 5 min, 2 cycles, a 100% flush volume, a purge time of 120 s, and 1 g Florisil as in-cell clean-up extraction sorbent. The use and optimization of an in-cell clean-up sorbent was necessary to remove fatty interferents of the PLE extract that make the subsequent ionic liquid-based headspace single-drop microextraction difficult. Validation parameters, namely LODs and LOQs, ranged from 0.5-1.5 to 2.5-5 ng/g, respectively. Good levels of intra- and interday repeatabilities were obtained analyzing sewage sludge samples spiked at 10 ng/g (n = 3, RSDs < 10%). The method applicability was tested with sewage sludge from different wastewater treatment plants. The analysis revealed the presence of all the polycyclic musks studied at concentrations higher than the LOQs, ranging from 6 to 530 ng/g. However, the nitro musk concentrations were below the LOQs or, in the case of musk xylene, was not detected., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A method for the quantitative determination of the nine EPA N-nitrosamines in sewage sludge was developed by using pressurised hot water extraction (PHWE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to chemical ionization ion trap tandem mass spectrometry (GC-CI-MS-MS). The pressurised hot water extraction was optimized using a central composite design with regard to operational parameters such as temperature, extraction time and pH of water as extracting solvent. The optimum conditions were: water at pH 7.5 as extracting solvent, temperature of 125°C and extraction time of 5 min. The sewage sludge extract was automatically analyzed by HS-SPME using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and GC-CI-MS-MS. The limits of detection of all compounds were lower than 0.15 μg/kg of dry weight (d.w.) of sewage sludge. The repeatability and reproducibility between days (10μg/kg d.w.) expressed as relative standard deviation were lower than 16 and 19%, respectively. The method was applied to determine the N-nitrosamines in sewage sludge from urban and industrial sewage treatment plants (STPs) and from a potable water treatment plant. Some N-nitrosamines were determined in the samples and N-nitrosodiethylamine (NDEA) and N-nitrosodi-n-butylamine (NDBA) showed the highest values (371 and 305 μg/kg (d.w.), respectively) in sewage from industrial STPs., (Copyright © 2011 Elsevier B.V. All rights reserved.)

An automated, environmentally friendly, simple, selective, and sensitive method was developed for the determination of ten primary aliphatic amines in sewage sludge at μg/kg dry weight (d.w.). The procedure involves a pressurized hot water extraction (PHWE) of the analytes from the solid matrix, followed by a fully automated on-fiber derivatization with 2,3,4,5-pentafluorobenzaldehyde (PFBAY) and headspace solid-phase microextraction (HS-SPME) and subsequent gas chromatography ion-trap tandem mass spectrometry (GC-IT-MS-MS) analysis. The limits of detection (LODs) of the method were between 0.5 and 45 μg/kg (d.w.) for all compounds except for ethyl-, isopropyl-, and amylamine, whose LODs were 70, 109, and 116 μg/kg (d.w.), respectively. The limits of quantification (LOQs) were between 10 and 350 μg/kg (d.w.). Repeatability and intermediate precision, expressed as RSD(%) (n=3), were lower than 18 and 21%, respectively. The method developed enabled to determine primary aliphatic amines in sludge from various urban and industrial sewage treatment plants as well as from a potable treatment plant. Most of the primary aliphatic amines were found in the sewage sludge samples analyzed corresponding to the maximum concentrations to the samples from the urban plant: for instance, isobutylamine and methylamine were found at 7728 and 12 536 μg/kg (d.w.), respectively. Amylamine was detected only in few samples but always at concentrations lower than its LOQ., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A solid-phase extraction and liquid chromatography-tandem mass spectrometry (SPE/LC-MS-MS) method was developed and validated for the simultaneous determination of nicotine, five drugs of abuse (morphine, cocaine, codeine, methadone, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) and four metabolites (dihydrocodeine, 6-acetylmorphine, 11-nor-carboxy-Δ(9)-tetrahydrocannabinol, and benzoylecgonine) in water samples. A Fused-Core™ particle column was used as an alternative to sub-2-μm particles in chromatographic separations to work with low backpressures and high efficiencies in short analysis times. Drugs were extracted from waste and surface water with SPE using Oasis MCX cartridges. Electrospray (ESI) in positive and negative mode and tandem MS selected reaction monitoring mode were used for identification and quantification. Calibration by linear regression analysis with deuterated internal standards was used to compensate the matrix effects. Limits of detection were found as low as 0.5-1 ng/L (surface water) and 1-50 ng/L (wastewater). The method was applied to the analysis of different kinds of samples. Wastewater from a sewage treatment plant was collected from three sampling points (after primary, secondary, and tertiary treatments) for a week. The analysis of the samples revealed a significant presence of these drugs in samples from primary treatments, where maximum concentrations of nicotine (1105 ng/L) and benzoylecgonine (3336 ng/L) were found. Most of the compounds showed values between

The present study evaluates the presence of nine hormones and their conjugates and 20 pharmaceuticals such as anti-inflammatories, lipid regulators, and antibiotics among others in sewage sludge from two sewage treatment plants (STPs) in the Tarragona area (Spain) for the period March 2007 until March 2008. Target analytes have been determined using different methods involving pressurized liquid extraction and liquid chromatography (electrospray ionization) tandem mass spectrometry (MS-MS). Most of the pharmaceuticals and hormones were found at low micrograms per kilogram dry weight levels in the sewage sludge samples analyzed. Some compounds were present in all samples, such as acetaminophen, caffeine, carbamazepine, and ibuprofen, among others. Other compounds, such as estriol, were found only in the STP of Reus. The compounds that showed the highest concentration in both STPs were roxithromycin and tylosin (1,446 and 1,958 microg/kg dry wt, respectively). The presence of these compounds in sewage sludge demonstrated that they are partially or totally removed from the influent wastewater by sorption into the sewage sludge., (Copyright (c) 2010 SETAC.)

In this paper we describe an environmentally friendly and sensitive method for the determination of ten primary amines in sewage sludge. The method is based on pressurised hot water extraction (PHWE) followed by simultaneous derivatization with pentafluorobenzaldehyde (PFBAY) and headspace solid-phase microextraction (HS-SPME) and subsequent gas-chromatography ion-trap tandem mass spectrometry (GC-IT-MS-MS) analysis. The influence of the main factors on the PHWE of sludge was optimized by a central composite design. For all species the optimal conditions were water at pH 4 as the extracting solvent, an extraction temperature of 100 degrees C and an extraction time of 15 min. The separation and detection of the ten amines by GC-IT-MS-MS took just 10 min and the entire process took approximately 1 h. Repeatability and reproducibility between days, expressed as RSD (%) (n=5), were less than 19 and 24%, respectively. The average limit of detection (LOD) was of 65 microg kg(-1) s (range found 9-135) and the average limit of quantification (LOQ) was of 230 microg kg(-1) (range found 50-450) of dry weight (d.w.). Under optimized conditions we used this method to determine the compounds in industrial and municipal sewage sludge samples and in sludge from a potable water treatment plant. Methylamine and isobutylamine showed the highest levels in one of the industrial sewage sludge samples (404 and 543 mg kg(-1) (d.w.), respectively). To our knowledge, this paper presents for the first time the determination of ten primary amines in sewage sludge samples using PHWE., (Copyright 2010 Elsevier B.V. All rights reserved.)

The contamination of wastewater and sewage sludge has been examined for three phosphodiesterase type V inhibitors sildenafil, vardenafil and tadalafil, active agents of Viagra, Levitra and Cialis, respectively. Sensitive quantification methods based on solid-phase extraction (SPE) and pressurized liquid extraction (PLE) followed by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) have been developed to analyse these compounds in wastewater and sewage sludge. Effluent water of nine sewage treatment plants (STPs) has been analysed to assess the impact of the phosphodiesterase type V inhibitors on the environment. One municipal STP (Tarragona, Spain) has been thoroughly studied over the year 2008 (i) with respect to the distribution of these compounds among influent and sewage sludge and (ii) the elimination efficiency. The developed methods allowed quantification at trace concentrations. Sildenafil was present in all investigated samples at the low ng/L and ng/g range, respectively. Tadalafil was not detected or below the limit of detection (LOQ) in effluent water taken in Spain but in sewage sludge (12 ng/g - < LOQ). Vardenafil was present only in one sludge sample and between 5 ng/g and < LOQ in effluent water. The overall removal efficiency of the STP in Tarragona (Spain) is 68%, 69% and 80% for sildenafil, tadalafil and vardenafil, respectively. This study shows for the first time the determination of these compounds in wastewater and sewage sludge., (Copyright 2009 Elsevier Ltd. All rights reserved.)

This paper describes a method for the determination of a group of personal care products including four UV filters, four preservatives and two antimicrobials in sewage sludge. The method combines pressurized liquid extraction and ultra high performance liquid chromatography-tandem mass spectrometry. Most of the parameters that affect the extraction step such as temperature, pressure, static extraction time, number of cycles, purge time and flush volume were optimized using a fractional experimental design. In the chromatographic step, the compounds were detected by using tandem mass spectrometry with a triple quadrupole analyzer with electrospray ionization in positive and negative modes. The use of small diameter particles (1.8 microm) in the chromatographic column allowed the compounds to be eluted in 9 min. The entire process took a total of 39 min. All recoveries were higher than 72% except for 2,4-dihydroxybenzophenone (a UV filter), whose recovery was 30%. The repeatability and reproducibility between days expressed as RSD (%) (n=3) were less than 8% and 13%, respectively. The LODs and LOQs were lower than 8 microg/kg and 12.5 microg/kg of dry weight (d.w.), respectively. When the method was applied to determine the compounds in sewage sludge from a domestic sewage treatment plant, triclosan (an antimicrobial) and octocrylene (a UV filter) showed the highest levels, 1490 microg/kg (d.w.) and 1842 microg/kg (d.w.), respectively. This paper describes for the first time the determination of parabens and two UV filters (octyldimethyl-p-aminobenzoic acid and benzophenone-3) in sewage sludge.

In this study we present a pressurized liquid extraction/liquid chromatography-tandem mass spectrometry (PLE/LC-MS-MS) method to determine a group of estrogens and conjugated estrogens in sewage sludge. Parameters that affect the extraction step such as extraction solvent, temperature, pressure, static extraction time, number of cycles, purge time and flush volume have been optimized. In the LC-MS-MS system, electrospray ionization and a triple quadrupole analyzer have been used, and the multiple reaction monitoring mode has enabled low levels of target analytes to be detected. All recoveries were higher than 81% except for estrone 3-glucoronide and estradiol 17-glucoronide which were not extracted and consequently, they were not considered in the present study. The repeatability and reproducibility between days expressed as %RSD (n=3), were lower than 6% and 9%, respectively. The method developed allowed the target analytes to be quantified at low levels of microg/kg. The limits of detection were lower than 26 microg/kg of dry weight (d.w.) of sewage sludge, except for 17 alpha-estradiol, 17beta-estradiol, 17 alpha-ethinylestradiol and estradiol 17-acetate whose values were between 150 and 175 microg/kg (d.w.). The method was applied to determine these compounds in sewage sludge from two domestic sewage treatment plants. Estrone 3-sulfate, estradiol 3-sulfate, diethylstilbestrol, estrone and estriol were determined in some samples and estriol showed the highest value (406 microg/kg d.w.).

A method for the quantitative determination of three macrolides, five sulfonamides, ranitidine, omeprazole and trimethoprim in sewage sludge samples was developed by using pressurized liquid extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. The extraction solvent and such operational parameters as temperature, pressure, extraction time and purge time were optimized in pressurized liquid extraction. The experimental conditions were: an extraction solvent of water (pH 3):methanol (1:1, v/v), a temperature of 80 degrees C, a pressure of 1500 psi, a sample weight of 5 g, an extraction time of 5 min, one cycle, a flush volume of 60% and a purge time of 120 s. All recoveries were over 74%, except those for ranitidine whose value was 54%. The repeatability and reproducibility between days expressed as relative standard deviation (n = 3) were lower than 11% and 15%, respectively. The limit of detection values ranged from 2 to 11 microg/kg dry weight (d.w.). The method was applied to determine the pharmaceuticals in sewage sludge from two domestic sewage treatment plants. Roxithromycin and tylosin were determined in the samples and tylosin showed the highest value (4.0 mg/kg d.w.).

A method for the quantitative determination of ten pharmaceuticals in sewage sludge was developed by using pressurized liquid extraction (PLE) and HPLC-MS with ESI (HPLC-(ESI)MS). The PLE was optimized with regard to solvents and operational parameters, such as temperature, pressure, extraction time, and purge time. The optimum conditions were: 50 mM phosphoric acid/methanol (1:1 v/v) as the extraction solvent, temperature of 100 degrees C, pressure of 100 bar, extraction time 15 min, 2 cycles, flush volume 150% and purge time 300 s. All recoveries for pharmaceuticals were over 68% except for salicylic acid. The repetitivity and reproducibility between days expressed as RSD was lower than 8% for repetitivity and 10% for reproducibility. The LOD of all compounds was lower than 10 microg/kg of dry weight of sewage sludge. The method was applied to determine the pharmaceuticals in sewage sludge from two domestic sewage treatment plants (STPs). The samples were collected every three months between February 2004 and June 2005. Some pharmaceuticals were determined in the samples and naproxen showed the highest value (242 microg/kg of dry weight).

[Display omitted] • Development of analytical method based on SPE/LC-MS/MS to determine pharmaceuticals. • Suitable figures of merit in terms of recovery, matrix effect and precision. • Monitoring of pharmaceuticals in different influent wastewater samples. • Six Spanish wastewater treatment plants (WWTPs) were monitored during one week. • Similar concentrations and population normalized daily loads of pharmaceuticals in the studied WWTPs. The occurrence of pharmaceuticals in influent wastewater samples (IWW) is a recurrent issue. The monitoring of their presence is not only valuable from an environmental point of view, but also as a tool to analyze patterns of human use by the so-called wastewater-based epidemiology. The development of an analytical method based on solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry to monitor the occurrence of a group of seventeen pharmaceuticals including the most representative for various therapeutic families in IWW samples is described in this work. The samples were collected during a monitoring week in six wastewater treatment plants located in different cities and towns across Spain. The developed method provides acceptable figures of merit with apparent recoveries in IWW ranging from 42% to 139%, and low matrix effect (in general lower than ± 30%), and method quantification limits (MQL) between 1 ng/L and 24 ng/L for all compounds, except atenolol (58 ng/L). All the studied pharmaceuticals were found in all samples with concentrations ranging from < MQL to 10,393 ng/L, being the highest concentrations for tramadol. The population normalized daily loads revealed that the use of pharmaceuticals follows, in general, a similar pattern in all cities monitored. [ABSTRACT FROM AUTHOR]

A method for simultaneous determination of four benzodiazepines (bromazepam (BMZ), carbamazepine (CBZ), diazepam (DZP) and nordiazepam (NDZ)) and four barbiturates (barbital (BTL), pentobarbital (PTB), phenobarbital (PNB) and secobarbital (SCB)) in river water and wastewater using solid-phase extraction (SPE) followed by liquid chromatography-(electrospray) tandem mass spectrometry (LC-(ESI)MS/MS) was developed. LC-(ESI)MS/MS analysis was performed in positive and negative modes for benzodiazepines and barbiturates, respectively, and in selected reaction monitoring (SRM). Limits of detection (LODs) were in the range of 0.2–5 ng/L for benzodiazepines and 2.5–50 ng/L for barbiturates. Precision (repeatability and reproducibility between days) expressed as %RSD (n = 5) was lower than 17% for low concentration (depending on the matrix between 50 and 250 ng/L for barbiturates, and between 5 and 25 ng/L for benzodiazepines), and lower than 15% for high concentration (between 200 and 1250 ng/L for barbiturates, and between 20 and 125 ng/L for benzodiazepines). Low matrix effect was observed for all compounds, except for BTL (75%) and PTB (–48%) in wastewater. The method was applied to water samples from two sewage treatment plants (STPs) and the rivers Ebre, Ter and Llobregat, located in Catalonia. CBZ was the target compound found at the highest concentration in river water (2.1–3.3 ng/L). In both influent and effluent wastewater samples, PNB, BMZ, CBZ, DZP and NDZ were determined at concentration levels ranging from 5.0 to 2337.3 ng/L. [ABSTRACT FROM AUTHOR]

This study compares the separation performance of a group of iodinated X-ray contrast media on four different columns. The first three were two stationary phases (SPs) modified with C18 and a polar-embedded SP (polar amide group bonded to an alkyl chain), all of which worked under RP-LC mode. The fourth was a zwitterionic sulphoalkylbetaine SP, working under the hydrophilic interaction LC (HILIC) mode. After the optimisation of the different parameters, the zwitterionic column displayed the best separation, which also overcomes the problems encountered when these analytes were separated under RP-LC. Moreover, when HILIC is coupled to MS/MS, sensitivity is enhanced. However, when sewage samples were analysed by SPE followed by the optimal HILIC-MS/MS, the sensitivity of the method was affected due to the high matrix effect, which had to be solved by dilution of the extract. Finally, the method was preliminarily validated with sewage and the figures of merit were comparable to those of the SPE-RP-LC-MS/MS. [ABSTRACT FROM AUTHOR]

A fully automated method has been developed for determining eight macrocyclic musk fragrances in wastewater samples. The method is based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC-MS). Five different fibres (PDMS 7 μm, PDMS 30 μm, PDMS 100 μm, PDMS/DVB 65 μm and PA 85 μm) were tested. The best conditions were achieved when a PDMS/DVB 65 μm fibre was exposed for 45 min in the headspace of 10 mL water samples at 100 °C. Method detection limits were found in the low ng L −1 range between 0.75 and 5 ng L −1 depending on the target analytes. Moreover, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations ( n = 5, 1,000 ng L −1) less than 9 and 14 %, respectively. The applicability of the method was tested with influent and effluent urban wastewater samples from different wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the target macrocyclic musks with, most notably, the maximum concentration of ambrettolide being obtained in WWTP A (4.36 μg L −1) and WWTP B (12.29 μg L −1), respectively. The analysis of effluent urban wastewater showed a decrease in target analyte concentrations, with exaltone and ambrettolide being the most abundant compounds with concentrations varying between below method quantification limit (−1. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An on-line coupling solid-phase extraction (SPE) has been developed for the first time to preconcentrate trace amounts of 17 musk fragrances extensively used in personal care products (6 polycyclic musks, 3 nitro musks, 7 macrocyclic musks and 1 polycyclic musk degradation product) from wastewater samples, prior to analysis by gas chromatography and mass spectrometry through an on-column interface. A 10 mm × 2 mm I.D. precolumn packed with Oasis HLB (60 μm) or C18 (60 μm) was compared for the optimization of the solid-phase extraction process. The parameters affecting the transfer of the analytes from the precolumn to the GC system (e.g. flow-rate, temperature and solvent vapor exit time) as well as SPE parameters (e.g. sample flow, sample volume, elution solvent, etc.) were optimized. An organic modifier such as methanol was added to the sample before the extraction process to avoid adsorption problems. The use of the MS detector under selected ion monitoring acquisition enabled the analytes to be quantified at low ng L −1 levels, preconcentrating only 10 mL of sample, and the limits of detection were between 1 and 30 ng L −1 . The method was applied for the determination of musk fragrances in wastewater samples from three urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed that galaxolide, tonalide and ambrettolide were the most abundant musk compounds with concentrations ranging between 18 ng L −1 and 45,091 ng L −1 , 852 ng L −1 and 49,904 ng L −1 and 507 ng L −1 and 21,528 ng L −1 respectively. The remaining musks were present at lower concentrations and two of the macrocyclic musk studied (musk MC4 and civetone) were not detected. The analysis of effluent wastewater showed a decrease in the concentrations of all of the compounds present in influent samples, with the decrease being more significantly in the case of polycyclic and nitro musks than for macrocyclic musks. Only HHCB-lactone remained constant or increased its concentration. [ABSTRACT FROM AUTHOR]

We developed a sensitive method based on solid-phase extraction and high-performance liquid chromatography coupled to mass spectrometry using an electrospray interface for the determination of four tetracyclines and two quinolones in water. The method was applied to river, well and sewage-treatment-plant waters. For the solid-phase extraction of 1000 ml river water samples, recoveries were between 88 and 112% and limits of detection were as low as 4 and 6 ng l−1. Recoveries were higher than 64% for 1000 ml well water samples for the majority of the compounds. For the influent and effluent of the sewage-treatment-plant sample volumes of 100 and 250 ml were extracted, respectively. The method developed allowed ciprofloxacin to be determined in samples from the influent and effluent of the sewage-treatment-plant at 0.58 and 0.60 μg l−1, respectively. [Copyright &y& Elsevier]