Trace determination of organotin compounds in water,sediment and mussel samples by low-pressure gas chromatography coupled to tandem mass spectrometry

A fast method for the determination of eight organotin compounds (OTs), monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), tetrabutyltin (TeBT), monophenyltin (MPhT), diphenyltin (DPhT), triphenyltin (TPhT) and tetraphenyltin (TePhT), in water, sediments and mussels, was developed using low-pressure gas chromatography/tandem mass spectrometry (LPGC/MS/MS). The method is based on sodium diethyldithiocarbamate (DDTC) complexation of the ionic organotins, followed by extraction of the target matrices and derivatization by a Grignard reagent, as described in a previously published method for water samples. Solid-phase extraction was selected as extraction method from water samples after comparison with liquid-liquid extraction, but extraction of the OTs from sediment and mussel samples was performed using toluene. Matrix-matched calibration standards were used to minimize matrix effects. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, detection limit (LOD), quantitation limit (LOQ), precision, and recovery were determined. Recoveries of OTs in spiked matrices ranged from 86-108% in water and from 78-110% in sediments and mussels, with precision values lower than 18%. Detection limits ranged from 0.1-9.6 ng L(-1) in water, and 0.03-6.10 microg kg(-1) in the other matrices. The present implementation of LPGC rather than conventional capillary GC permitted use of large-volume injection and reduced analysis time by a factor of two. The proposed methodology was applied to the determination of OTs in real samples of water, marine sediments and mussels from the west coast of the Mediterranean Sea (Spain).     

Parts per trillion level determination of endocrine-disrupting chlorinated compounds in river water and wastewater effluent by stir-bar-sorptive extraction followed by gas chromatography–triple quadrupole mass spectrometry

A new analytical method using stir-bar-sorptive extraction (SBSE) followed by liquid desorption (LD) and gas chromatography with triple-quadrupole mass spectrometric detection (GC-QqQ-MS-MS) has been used for quantitative determination of 25 chlorinated endocrine-disrupting compounds (EDCs) in river water and wastewater. The experimental conditions affecting the SBSE-LD performance were studied and are discussed in detail. Results from systematic assay revealed that a 100-mL water sample, stir bars coated with 47?μL PDMS, an extraction time of 14?h (at 900?rpm), 5?% MeOH as modifier and 10?% NaCl resulted in the best analytical recovery of all the target compounds studied. Use of 1:1 ACN-MeOH as back-extraction solvent and two successive sonication steps, each for 5?min, resulted in the best performance for monitoring EDCs in water matrices. The method detection limits for most of the target compounds were very good- ≤?2?ng?L(-1) and ≤10?ng?L(-1) for river water and wastewater effluents respectively. Experimental recovery for all the compounds was >70?%, with the exception of simazine for which recovery from the matrix was 65?%. Signal enhancement observed for a few of the compounds in wastewater effluents was managed by use of matrix-matched standards and different injection liners. The method was successfully used for analysis of river water samples from Henares River (Spain) and wastewater effluent samples from wastewater-treatment plants (WWTP). Eleven of the 25 compounds studied were detected in both river water and wastewater effluents. Terbutylazine and methoxychlor were detected in almost all the river water and effluent samples; amounts varied between 37-58.5?ng?L(-1) and 15.2-46.8?ng?L(-1), respectively. This method was shown enable reliable, effective, and sensitive monitoring of chlorinated EDCs at nanogram levels in surface water and wastewater effluent.     

Solid‐phase Extraction Coupled Simple On‐line Derivatization Gas Chromatography – Tandem Mass Spectrometry for the Determination of Benzophenone‐type UV Filters in Aqueous Samples

The rapid determination of three benzophenone‐type UV filters: 2‐hydroxy‐4‐methoxy‐benzophenone (BP‐3), 2,4‐dihydroxybenzophenone (BP‐1) and 2,2′‐dihydroxy‐4‐methoxy‐benzophenone (BP‐8), in aqueous samples is described. The method involved the extraction of an aqueous sample using an Oasis HLB solid‐phase extraction (SPE) cartridge, followed by on‐line derivatization gas chromatography ‐ tandem mass spectrometry (GC‐MS/MS) with a trimethylsilylating (TMS) reagent. This eco‐friendly, injection‐port derivatization method, is sensitive, rapid, and provides reproducible results for these hydroxylated benzophenones in aqueous samples. The limits of quantitation (LOQs) were determined to be 1.0 to 2.5 ng/L for samples in 100 mL of water. The precision for these analytes, as indicated by relative standard deviations (RSDs), proved to be less than 11% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction yield, was between 80 and 106%. The method was then applied to some environmental water samples, river water and samples of effluents from a wastewater treatment plant (WWTP), having the potential to contain BP‐3 and BP‐1.     

Trace analysis of 28 steroids in surface water, wastewater and sludge samples by rapid resolution liquid chromatography-electrospray ionization tandem mass spectrometry

A sensitive rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method, combined with solid-phase extraction, ultrasonic extraction and silica gel cartridge cleanup, was developed for 28 steroids including 4 estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethynyl estradiol (EE2), diethylstilbestrol (DES)), 14 androgens (androsta-1,4-diene-3,17-dione (ADD), 17α-trenbolone, 17β-trenbolone, 4-androstene-3,17-dione, 19-nortestoserone, 17β-boldenone, 17α-boldenone, testosterone (T), epi-androsterone (EADR), methyltestosterone (MT), 4-hydroxy-androst-4-ene-17-dione (4-OHA), 5α-dihydrotestosterone (5α-DHT), androsterone (ADR), stanozolol (S)), 5 progestagens (progesterone (P), ethynyl testosterone (ET), 19-norethindrone, norgestrel, medroxyprogesterone (MP)), and 5 glucocorticoids (cortisol, cortisone, prednisone, prednisolone, dexamethasone) in surface water, wastewater and sludge samples. The recoveries of surface water, influents, effluents and sludge samples were 90.6-119.0% (except 5α-DHT was 143%), 44.0-200%, 60.7-123% and 62.6-138%, respectively. The method detection limits for the 28 analytes in surface water, influents, effluents and freeze-dried sludge samples were 0.01-0.24 ng/L, 0.02-1.44 ng/L, 0.01-0.49 ng/L and 0.08-2.06 ng/g, respectively. This method was applied in the determination of the residual steroidal hormones in two surface water of Danshui River, 12 wastewater and 8 sludge samples from two wastewater treatment plants (Meihu and Huiyang WWTPs) in Guangdong (China). Ten analytes were detected in surface water samples with concentrations ranging between 0.4 ng/L (17β-boldenone) and 55.3 ng/L (5α-DHT); twenty analytes in the wastewater samples with concentrations ranging between 0.3 ng/L (P) and 621 ng/L (5α-DHT); and 12 analytes in the sludge samples with concentrations ranging between 1.6 ng/g (E1) and 372 ng/g (EADR).     

固相萃取-高效液相色谱-串联质谱法同时测定养殖海水中23种抗生素

建立了固相萃取-高效液相色谱-串联质谱(SPE-HPLC-MS/MS)同时检测水中6类23种抗生素的分析方法。水样用固相萃取柱富集净化,通过对比水样在不同上样pH、洗脱液用量等条件下的回收率,优化了前处理方法。采用0.1%(v/v)甲酸-1 g/L甲酸铵水溶液和甲醇-乙腈(1:1, v/v)体系作为流动相,经过梯度洗脱进行分离,在HPLC-MS/MS多反应监测模式下进行定性定量分析。结果显示,23种抗生素的方法检出限(MDL)范围为0.1~2.9 ng/L,加标回收率为47.3%~132.6%。采用该方法对东营海水养殖区5个养殖池水样进行了检测,除青霉素类之外的各类抗生素均有检出,其中磺胺增效剂甲氧苄氨嘧啶的检出率达100%,氯霉素类抗生素氟甲砜霉素检出的最高质量浓度达到261.0 ng/L。结果表明,所建立的方法高效、灵敏、可靠,可用于海水中多种抗生素的分析。     

C_(18)膜萃取/液相色谱-质谱联用法测定极地水体中有机磷酸酯

建立了C_(18)膜萃取/液相色谱-质谱联用技术测定极地水体中10种有机磷酸酯(OPEs)的方法。根据优化后的样品前处理及仪器方法,利用C_(18)膜富集4 L水体中的10种OPEs,经二氯甲烷超声提取,在电喷雾正离子模式下,采用选择反应监测(SRM)模式进行分析,线性相关系数为0.994 4~0.999 9。10种OPEs的加标回收率为64.1%~115%,方法检出限为0.08~0.55 ng/L。该方法适用于极地水体中10种OPEs的分析,利用该方法对北极水体样品中的10种OPEs进行检测,测得冰川融水中∑OPEs的质量浓度为0.64~6.64 ng/L,海水中∑OPEs的质量浓度为0.09~2.03 ng/L。     

Trace Determination of Benzalkonium Chlorides in River and Wastewater by Capillary Electrophoresis following Solid‐Phase Extraction Coupled with Salting‐Out Extraction

Trace levels analysisbenzalkonium chlorides (BAKs) in river water and wastewater treatment plants (WWTP) effluents were determined by capillary electrophoresis (CE) following solid‐phase extraction (SPE) and salting‐out extraction. Salting‐out extraction using an appropriate ratio of sodium chloride (NaCl) and acetonitrile (ACN) mixed with concentrated SPE elutant was capable of providing more than 500‐fold enhancement in detection sensitivity. The ratios of ACN and NaCl for salting‐out extraction were investigated and optimized. Matrix interference was eliminated by salting‐out extraction. Limits of quantitation of BAK homologues were achieved at 0.1 μg/L in 250 mL water samples. Recoveries of BAKs in various spiked water samples ranged from 70% to 84% with relative standard deviation (RSD) less than 9%. Trace amounts of total BAKs were detected in river water and WWTP effluent samples ranging from 27 to 145 μg/L at the first time by CE.     

Determination of phenolic xenoestrogens in environmental samples by liquid chromatography with mass spectrometric detection

A method is proposed for the determination of several phenolic xenoestrogens in aqueous and solid environmental samples. The method uses solid-phase extraction (preceded by ultrasonic solvent extraction for solid samples), reversed-phase liquid chromatographic separation, and mass spectrometric detection using both atmospheric pressure chemical ionization and electrospray ionization. This method was developed to support several studies undertaken to obtain aquatic and sedimentary data for rivers and seashores in Spain that are likely to be contaminated by endocrine-disrupting compounds (EDCs) as a consequence of wastewater discharge. Nonylphenol polyethoxylates (NPEOs), nonylphenoxy carboxylates (NPECs), nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were determined in various samples of surface water and sediment, collected at different locations upstream and downstream from outfalls of municipal wastewater treatment plants (WWTPs). Seawater and marine sediments were collected in different harbor areas in Spain. Additionally, WWTP influent and effluents were analyzed to monitor the occurrence and transformation of phenolic EDCs during physicochemical and biological treatment. Rather high concentrations of the compounds investigated were found in some samples. Concentrations of NP were < or = 590 microg/kg in sediments and < or = 15 microg/L in water samples. NPEOs and NPECs were found in water samples in concentrations < or = 41 and < or = 35 microg/L, respectively. In solid samples (river sediment), concentrations of NPEO were < or = 818 microg/kg and those of NP1EC were 95 microg/kg.     

Comparison of multiple API techniques for the simultaneous detection of microconstituents in water by on‐line SPE‐LC‐MS/MS

This study described a fully automated method using on‐line solid phase extraction of large volume injections coupled with high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) to simultaneously detect a group of recalcitrant microconstituents (pharmaceuticals and personal care products, steroid hormones and sterols) in aqueous matrices. Samples (1 mL to 20 mL) were loaded to the preconcentration column at 1 mL/min, and the column was washed with 1000 μL of 25% methanol in LC/MS water to remove polar and ionic interferences before LC‐MS/MS analysis. Three different atmospheric pressure ionization (API) techniques, including photoionization (APPI) with four different dopants (acetone, anisole, chlorobenzene and toluene), heated electrospray ionization (HESI) and atmospheric pressure chemical ionization (APCI), were evaluated on the basis of method detection limits (MDLs) and recoveries from different aqueous matrixes. Results indicated that APPI with toluene as dopant was the most sensitive ionization method for the majority of the analytes. When using 5 mL of sample, MDLs for pharmaceuticals and personal care products, including carbamazepine, DEET, caffeine, naproxen, acetaminophen and primidone, were between 0.3 ng/L and 15 ng/L. MDLs of hormones, including testosterone, equilenin, progesterone, equilin, 17β‐estradiol, 17α‐ethynylestradiol, estrone, androsterone, mestranol and estriol, were between 1.2 ng/L and 37 ng/L. The combination of APPI with dopant allowed the detection of two difficult to ionize fecal related sterols, such as coprostan‐3‐ol and coprostan‐3‐one with MDLs of 5.4 ng/L and 11 ng/L, respectively. Calculated MDLs are more than adequate for analysis of wastewater using 1 to 5 mL sample size and for surface waters using up to 20 mL sample size. Copyright © 2012 John Wiley & Sons, Ltd.     

Analysis of alkyl and 2-6-ringed polycyclic aromatic hydrocarbons by isotope dilution gas chromatography/mass spectrometry. Quality assurance and determination in Spanish river sediments

An accurate, precise and sensitive method is described for the analysis of 29 polycyclic aromatic hydrocarbons (PAHs), including 19 2-6-ringed PAHs and 10 alkyl-PAHs. The method is based on an isotope dilution technique using gas chromatography/mass spectrometry (GC/MS) and available labeled PAHs as internal standards. Quality parameters were calculated with satisfactory results and 36 Spanish river sediments were analysed. Results were evaluated regarding to the sediment quality guidelines (SQGs) based on the effects range-low (ERL) and the effects range-median (ERM) values. Most analysed sediments showed a good quality, since only 7 of them exceeded ERL values, including one sample surpassing ERM values. PAH profiles were studied in order to identify PAH sources as mainly petrogenic or pyrogenic. Most samples showed petrogenic-type fingerprints, although 6 of the 11 sediments with the highest PAH concentrations (> 1000 ng/g) were classified as pyrogenic, including 4 of the 7 samples exceeding ERL values. Quality assurance was carried out by the triplicate analysis of one preanalysed river sediment without PAHs subsequently spiked at a medium (500 ng/g) and a low concentration level (10 ng/g) of each analyte. Main quality requirements for methods based on isotope dilution were accomplished. Method accuracy was 80-120% for most PAHs, method precision was <15% for all the analysed compounds and method detection limits (MDLs) were 1-3 ng/g.     

Dispersive Micro Solid‐phase Extraction Coupled with Ultrasound‐assisted Solvent Desorption for Determination of Synthetic Polycyclic and Nitro‐aromatic Musks in Aqueous Samples

An optimized method for the determination of five synthetic polycyclic: celestolide (ADBI), phantolide (AHMI), traseolide (ATII), galaxolide (HHCB), tonalide (AHTN), and two nitro‐aromatic musks: musk xylene (MX) and musk ketone (MK), in water samples is described. The method involves a dispersive micro solid‐phase extraction (D‐μ‐SPE) plus ultrasound‐assisted solvent desorption (UASD) prior to their determination by gas chromatography‐mass spectrometry (GC‐MS) using the selected ion storage (SIS) mode. Factors affecting the extraction efficiency of the target analytes from water samples and ultrasound‐assisted solvent desorption were optimized by a Box‐Behnken design method. The optimal extraction conditions involved immersing 10.1 mg of a typical octadecyl (C18) bonded silica adsorbent (i.e., ENVI‐18) in a 50 mL water sample. After 10.4 min of extraction by vigorously shaking, the adsorbent was collected and dried on a filter, and the target musks were desorbed by ultrasound‐assisted for 38 sec with n‐hexane (200 μL) as the desorption solvent. A 10 μL aliquot was then directly determined by large‐volume injection GC‐MS. The limits of quantitation (LOQs) were 1.2 to 5 ng/L. The precision for these analytes, as indicated by relative standard deviations (RSDs), were less than 11% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction recovery, was between 74% and 92%. A preliminary analysis of the effluents from municipal wastewater treatment plants (MWTP) and river water samples revealed that HHCB and AHTN were the two most commonly detected synthetic musks; their concentration were determined to range from 88 to 690 ng/L for effluent samples, and 5 to 320 ng/L for river water samples. This is a simple, low cost, effective, and eco‐friendly analytical method.     

Analysis of 21 progestagens in various matrices by ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) with diverse sample pretreatment

In this study, a highly sensitive and robust method using an ultra-high-performance liquid chromatography-tandem mass spectrometry combined with solid-phase extraction and ultrasonic extraction for pretreatment and silica gel purification steps has been developed for determination of 21 natural and synthetic progestagens in river surface water and sediments, and influents, effluents, and sludge from municipal wastewater treatment plants, and flush water and feces from swine farms. For the various matrices considered, the optimized method showed satisfactory performance with recoveries of 70–129 % (except AD, 5α-DHP, DPT, HPC), the limits of quantification below 2.30 ng/L for liquid samples and 2.59 ng/g for solid samples (except AD), and good linearity and reproducibility. This developed method was successfully applied in the analysis of progestagens in environmental samples from Liuxi Reservoir, Xintang municipal wastewater treatment plant, and Shunfeng swine farm in South China. Six analytes were detected at trace levels in surface water, effluent, and sediment samples. Seven analytes (0.7 (HPA)–35.1 ng/L (DGT)) were found in the influent samples and three analytes (5.6 (DGT)–11.8 ng/g (5α-DHP)) in the dewatered sludge samples. Moreover, 13 analytes were detected in swine farm, with high concentrations ranging from 23.8 ng/L (ET) to 5,024 ng/L (P) in flush water, and from 20.0 ng/g (MPA) to 1952 ng/g (P) in feces.     

Development and validation of a GC-EI-MS method with reduced adsorption loss for the quantification of olanzapine in human plasma

A simple and sensitive GC-EI-MS method using solvent extraction and evaporation was developed for the determination of olanzapine concentrations in plasma samples. Because olanzapine and promazine, which was used as the internal standard (IS), are nitrogenous bases, they can adsorb to the weakly acidic silanol groups on the surfaces of glass centrifuge tubes during solvent extraction and evaporation. Silylation of the glass tubes, addition of triethylamine (TEA), and use of a sample solution with a basic pH could prevent adsorption loss. The extraction method involved mixing plasma (500 μL) in a silylated glass tube with a promazine solution (2 μg/mL, 25 μL) in methanol containing 1% TEA. After addition of aqueous sodium carbonate (0.5 mol/L, pH 11.1, 1 mL) and extraction into 3 mL of dichloromethane/n-hexane (1:1, v/v) containing 1% TEA, the organic phase was evaporated to dryness in a silylated glass tube. The residue was dissolved in ethyl acetate containing 1% TEA (50 μL). For GC-EI-MS analysis, the calibration curves of olanzapine in human plasma were linear from 0.5 to 100 ng/mL. Intra- and interday precisions in plasma were both less than 7.36% (coefficient of variation), and the accuracy was between 94.6 and 110% for solutions with concentrations greater than 0.5 ng/mL. The limit of quantification was 0.5 ng/mL in plasma. The assay was applied to therapeutic drug monitoring in samples from three schizophrenic patients.     

Analysis of estrogens in river sediments by liquid chromatography-electrospray ionisation mass spectrometry. Comparison of tandem mass spectrometry and time-of-flight mass spectrometry

A method has been developed and optimised for the determination of two natural estrogens, estrone (E1) and 17beta-estradiol (E2), and one synthetic estrogen, 17alpha-ethynylestradiol (EE2), in river sediments at the sub-ng/g level. This procedure includes microwave-assisted solvent extraction (MASE), solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionisation. Using sediments spiked with the three estrogens at 10 ng/g wet weight, efficient extraction (>92%) of all the three analytes was achieved by MASE, and whole-procedure recoveries ranged from 82 to 98%. Optimisation of the LC separation allowed for substantial reduction of ionisation suppression in the electrospray source to a final level of <18% suppression. Time-of-flight mass spectrometry (TOF-MS) and MS/MS were compared for the analysis of sediment extracts, with the latter technique proving to be the most selective. The method detection limits achieved by LC-MS/MS were 15, 30 and 40 pg/g for E1, E2 and EE2, respectively, which were 13-fold lower than those obtained by LC-TOF-MS. Analysis of river sediments collected from the River Ouse, UK, showed the presence of the natural estrogens at sub-ng/g level. E1 levels ranged from 0.40 ng/g (dry weight) to 3.30 ng/g while E2 levels ranged from <0.03 to 1.20 ng/g and EE2 was never detected (<0.04 ng/g).     

Assessment of the occurrence and distribution of pharmaceuticals in a Mediterranean wetland (L'Albufera, Valencia, Spain) by LC-MS/MS

The distribution of 17 pharmaceuticals between water and the solid phase (sediments and soils) was studied by utilizing solid-phase extraction (SPE) and liquid chromatography?Ctandem mass spectrometry (LC-MS/MS). Two extraction procedures for soils and sediments, prior to the SPE, one based on pressurized liquid extraction (PLE) with hot water and the other on methanol/water ultrasonic extraction, were compared. Absolute recoveries were 71.2?C99.3% [relative standard deviation (RSD) <21.4%)] for water, and the method detection limits (MDLs) ranged from 0.3 to 10?ng?L^?1. Recoveries were 35.4?C105.3% (RSDs <19.1%) and 42.1?C97.8% (RSDs <14%) for soil and sediment samples, respectively, using PLE and 20.2?C86.5% (RSDs <25.1%) and 30.3?C97.4% (RSDs <19.1%) using ultrasonic extraction. Fifteen of the 17 pharmaceuticals were present in the L??Albufera water at concentrations up to 17???g?L^?1. Oxytetracycline and tetracycline were not detected. In sediments, only tetracycline, norfloxacin and diclofenac were not found. The other studied pharmaceuticals were present in the range from less than the method quantification limit (MQL) to 35.83?ng?g^?1. Among the 17 target compounds, ofloxacin, ciprofloxacin, norfloxacin, trimethoprim, clofibric acid and diclofenac were not detected in soil samples. The average concentrations ranged from less than the MQL for ibuprofen to 34.91?ng?g^?1 for tetracycline. These results indicate that pharmaceuticals could survive the wastewater treatment processes, which could lead to their dissemination in water environments.     

Determination of sixteen polycyclic aromatic hydrocarbons in aqueous and solid samples from an Italian wastewater treatment plant

A robust procedure for the determination of 16 US EPA PAHs in both aqueous (e.g. wastewaters, industrial discharges, treated effluents) and solid samples (e.g. suspended solids and sludge) from a wastewater treatment plant (WWTP) is presented. Recovery experiments using different percentages of organic modifier, sorbents and eluting solvent mixtures were carried out in Milli-Q water (1000 mL) spiked with a mixture of the PAH analytes (100 ng/L of each analyte). The solid phase extraction (SPE) procedures applied to spiked waste water samples (1000 mL; 100 ng/L spiking level) permitted simultaneous recovery of all the 16PAHs with yields >70% (6-13% RSD). SPE clean up procedures applied to sewage and stabilized sludge extracts, showed percent recoveries in the range 73-92% (7-13% RSD) and 71-89% (7-12% RSD), respectively. The methods were used for the determination of PAHs in aqueous and solid samples from the WWTP of Fusina (Venice, Italy). Mean concentrations, as the sum of the 16PAHs in aqueous and suspended solid samples, were found to be approx. in the 1.12-4.62 microg/L range. Sewage and stabilized sludge samples contained mean PAH concentrations, as sum of 16 compounds, in the concentration range of 1.44-1.26 mg/kg, respectively. Extraction and clean up procedures for sludge samples were validated using EPA certified reference material IRM-104 (CRM No. 912). Instrumental analyses were performed by coupling HPLC with UV-diode array detection (UV-DAD) and fluorescence detection (FLD).     

Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent

A method based on automated solid-phase extraction (SPE) and isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS) has been developed for the analysis of nine nitrosamines in water samples. The combination of automated SPE and GC/HRMS for the analysis of nitrosamines has not been reported previously. The method shows as advantages the selectivity and sensitivity of GC/HRMS analysis and the high efficiency of automated SPE with coconut charcoal EPA 521 cartridges. Low method detection limits (MDLs) were achieved, along with a greater facility of the procedure and less dependance on the operator with regard to the methods based on manual SPE. Quality requirements for isotope dilution-based methods were accomplished for most analysed nitrosamines, regarding to trueness (80–120%), method precision (<15%) and MDLs (0.08–1.7 ng/L).Nineteen water samples (16 samples from a drinking water treatment plant {DWTP}, 2 chlorinated samples from a sewage treatment plant {STP} effluent, and 1 chlorinated sample from a reservoir) were analysed. Concentrations of nitrosamines in the STP effluent were 309.4 and 730.2 ng/L, being higher when higher doses of chlorine were applied. N-Nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were the main compounds identified in the STP effluent, and NDEA was detected above 200 ng/L, regulatory level for NDMA in effluents stated in Ontario (Canada). Lower concentrations of nitrosamines were found in the reservoir (20.3 ng/L) and in the DWTP samples (n.d. −28.6 ng/L). NDMA and NDEA were respectively found in the reservoir and in treated and highly chlorinated DWTP samples at concentrations above 10 ng/L (guide value established in different countries). The highest concentrations of nitrosamines were found after chlorination and ozonation processes (ozonated, treated and highly chlorinated water) in DWTP samples.     

Application of dispersive liquid–liquid microextraction followed by HPLC–MS/MS for the trace determination of clotrimazole in environmental water samples

A method for the analysis of clotrimazole was developed with dispersive liquid–liquid microextraction for sample pre‐concentration and HPLC–MS/MS for analysis. A linear ion trap was used for the confirmation of clotrimazole identity in the samples. The developed method enables the analysis of clotrimazole in river water and sewage effluent from wastewater treatment plants with a LOQ of 0.7 ng/L. Environmental monitoring of clotrimazole was undertaken. Samples from river water and sewage effluents were analysed over a one‐year period. Clotrimazole was found in every tested sample with concentration range from 1 to 31 ng/L. The amount of clotrimazole in tested samples was highly dependent on sampling season. The highest results were obtained in summer and autumn.     

快速溶剂萃取-气相色谱-串联质谱法分析海洋沉积物中16种多环芳烃

建立了快速溶剂萃取（ASE）-气相色谱-串联质谱（GC-MS/MS）分析海洋沉积物中16种多环芳烃（PAHs）的分析方法。样品由正己烷-丙酮（1∶1,v/v）溶液萃取,经无水硫酸钠脱水、氮吹浓缩后,采用硅胶固相萃取小柱进行净化,然后经HP-5MS色谱柱（30 m×0.25 mm×0.25 μm）分离,在电子轰击电离源下以多反应监测（MRM）模式进行检测,内标法定量。分析结果表明,16种PAHs在0.01~1.00 mg/L范围内线性关系良好,相关系数（R）大于0.997;目标物的加标回收率为75.8%~97.8%;日内与日间精密度（RSD）均小于10%。当取样量为20.0 g时,16种PAHs的方法检出限为0.048~0.234 μg/kg。该法快速、准确、稳定,能够满足海洋沉积物中痕量PAHs的测定。     

Determination of estrogenic steroids in surface water and wastewater by liquid chromatography-electrospray tandem mass spectrometry

An analytical method is presented which permits trace level determination of 17alpha-ethynylestradiol (EE2), 17beta-estradiol (E2), and estrone (E1). Using this method, the estrogenic steroids were analyzed in drinking water, surface water, and wastewater (sewage influents and effluents) at concentrations down to 0.1 ng/L. Sample volumes between 100 and 500 mL are concentrated using automated solid-phase extraction. Analysis is performed by liquid chromatography with detection by tandem mass spectrometry. Applying simple clean-up procedures and internal standard calibration, recovery losses resulting from matrix-dependent ion suppression during electrospray ionization could be compensated for all of the investigated compounds. Recoveries around 100% were obtained for all analytes after correction using the internal standards. Limits of quantification (LOQ) were between 0.1 and 0.4 ng/L for purified sewage, surface, ground, and drinking water and between 1 and 2 ng/L in the case of raw sewage. Water treatment by wastewater treatment plants (WWTPs) or by a surface water treatment plant affected the removal of all estrogenic steroids. Thus, E1, E2, and EE2 were removed in the municipal WWTPs to the extent of 93%, 93%, and 80%, respectively. In the effluents of the WWTP in Ruhleben (Berlin, Germany), E1, E2, and EE2 were detected at the low ng/L level. E2 and EE2 were, however, not present in the Berlin surface water above the LOQ (0.2 ng/L). E1 was the only compound that could be detected in surface water samples. After additional surface water treatment it was still detectable but only at trace-level concentrations with a mean value of 0.16 ng/L.