A study on the behaviour of pesticides and their transformation products in the Scheldt estuary using liquid chromatography-electrospray tandem mass spectrometry

Off-line solid-phase extraction (SPE) combined with liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS-MS) was used to study the estuarine behaviour of the polar pesticides, atrazine, chloridazon, diuron and metolachlor, and their transformation products (TPs), hydroxyatrazine (HA), desisopropylatrazine (DIA), desethylatrazine (DEA), 3,4-dichlorophenylmethylurea (DPMU) and monuron. The compounds were identified by comparing their LC retention times and product-ion spectra with those of standard solutions. In all but one case the detection limits of the method were sufficient to determine the compounds of interest over the entire salinity range in the estuary. The concentrations of the dissolved pesticides ranged from 70 ng l-1 for chloridazon to 1350 ng l-1 for diuron. The levels of TPs were 3-8% of the levels of their parent pesticide. The mixing plots of polar pesticides and their TPs indicated that TPs, which are present in fresh river water, are conservatively transported to the sea and that no additional amounts of TPs are formed during their transport through the estuary. The one exception was HA, of which approximately 10% of the amount transported to the North Sea is formed in the lower part of the estuary by photochemical oxidation of atrazine. The latter was concluded from the ratios of each analyte over the sum total of the parent pesticide and all TPs along the salinity gradient, which proved to be a useful tool for identifying such estuarine transformations.     

Evaluation of river pollution of neonicotinoids in Osaka City (Japan) by LC/MS with dopant-assisted photoionisation

An atmospheric pressure photoionisation (APPI) source for liquid chromatography/mass spectrometry (LC/MS) was applied to determine neonicotinoid pesticides in the aquatic environment. Dopant-assisted APPI was very effective in the ionisation of neonicotinoids. Neonicotinoids generated protonated molecules in APPI with high sensitivity, while adduct ions, such as sodiated molecules, were predominantly generated in conventional electrospray ionisation. The ionisation of neonicotinoids was confirmed by ultra-high-resolution MS. An analytical method coupled with solid phase extraction was developed for acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, and thiamethoxam. Method detection limits were 0.47 to 2.1 ng L(-1) for six neonicotinoids. Dinotefuran was the most frequent and highest among the neonicotinoids examined in the aquatic environment in Osaka, Japan. The maximum concentration of dinotefuran was 220 ng L(-1). Given the toxicity of neonicotinoids for aquatic creatures, the concentrations observed here were substantially low. The change in concentrations was temporally coincident with the period of the neonicotinoid application. Although rapid photodegradation and some degradation products have been elucidated, the degradation products in the aquatic environment were not identified in the present study.     

Multi-component analysis of polar water pollutants using sequential solid-phase extraction followed by LC-ESI-MS

A multi-component screening analysis method for polar to medium-polar water pollutants was developed. Sample clean-up and group separation are performed by sequential solid-phase extraction (SSPE) using automated SPE with C18 and polymeric sorbent materials. Analyses are performed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) using a single-quadrupole instrument. More than 90 priority compounds of environmental interest--comprising the most important chemical and substance classes: phenols, carboxylic acids, aromatic sulfonates, aromatic amines, pharmaceuticals, surfactants, dyes, and pesticides--have been chosen for the experiments. The compounds are divided by the SSPE procedure into 3 different polarity classes. The extraction recoveries were determined in the 3 fractions for every single substance, and were for most of the analytes in the range of 50-100%. A mixture of hexane-dichloromethane was used for the elution of nonpolar compounds like alkylphenols from C18. Methanol and acetone are well suited for the elution of more polar substances. The limits of detection (LODs) were determined for all compounds. Effluents from municipal and industrial wastewater treatment plants (WWTPs) treating waste water from textile industries; and the corresponding receiving waters (rivers and lakes) have been analysed with the developed method. Urban and industrial pollution was observed in rivers and streams in the area north of Milan, Italy. In the water samples different phenols (nitrophenols, bisphenol A, nonylphenol), alkylphenol ethoxylate surfactants, their metabolites with endocrine disrupting potential, aromatic sulfonates, linear alkylbenzenesulfonate surfactants, dyes, pesticides, pharmaceuticals, and a dichlorobenzidine compound were identified.     

Determination of isocyanic acid in air

A method is presented for the determination of isocyanic acid (ICA), HNCO, in air samples as a di-n-butylamine (DBA) derivative. The method is based on sampling in midget impinger flasks containing 10 ml of 0.01 mol l-1 DBA in toluene. Quantification was made using liquid chromatography (LC) and electrospray mass spectrometry (MS) monitoring positive ions. The instrumental detection limit for the LC-MS was 10 fmol of ICA-DBA. ICA was generated by thermal decomposition of urea. A standard solution containing the DBA derivatives of ICA was prepared by collecting the emitted ICA in an impinger flask containing DBA. ICA in the reference solution was characterised by LC and time-of-flight (TOF) MS and quantified by LC chemiluminescent nitrogen detection (LC-CLND). The instrumental detection limit for the LC-CLND was 1 ng of nitrogen. ICA was emitted during thermal degradation of PFU resins and polyurethane (PUR) lacquers, from car metal sheets. ICA was the most dominant isocyanate and in PUR coating up to 8% of the total weight was emitted as ICA and for PFU resins up to 14% was emitted as ICA. When air samples were collected in an iron foundry during casting in sand moulds with furan resins, concentrations of ICA in the range 50-700 micrograms m-3 were found in the working atmosphere.     

固相萃取-超高效液相色谱-串联质谱法快速测定环境水样中30种极性农药

建立了固相萃取-超高效液相色谱-串联质谱快速测定环境水样中30种极性农药的方法。30种极性农药经过固相萃取(SPE)富集净化,以超高效液相色谱-串联质谱(UPLC-MS-MS)多级监测模式(MRM)外标法进行定性定量分析。结果表明:环境水样中30种极性农药的检出限为0.2～5 ng/L。对同一环境样品进行了低、中、高3个不同浓度水平的加标回收实验,平均回收率为63.7%～105.1%,相对标准偏差为4.4%～21.2%。该方法快速、灵敏、准确,可有效应用于环境水样中30种极性农药的快速监测。     

水中微囊藻毒素的超高效液相色谱-串联质谱法研究

建立测定水体中微囊藻毒素(MCYST)的超高效液相色谱-串联质谱分析方法.水样通过固相萃取富集净化,采用超高效液相色谱-串联质谱测定,6min内完成3种MCYST的分离及检测.MCYST-LR、MCYST-RR、MCYST-YR检出限分别为3.5、2.5、5.0ng/L,回收率为85.6％～107.9％,为水质微囊藻毒素监测提供了一种快速、准确、灵敏的分析方法.     

Determination of airborne anhydrides using LC-MS monitoring negative ions of di-n-butylamine derivatives

An air sampling method for simultaneous determination of organic acid anhydrides and isocyanates is presented. Air samples are collected in impinger flasks filled with 0.01 M di-n-butylamine (DBA) in a mixture of toluene-acetonitrile (7:3, v/v) with a 13 millimetre glass fibre filter in series. The amount of anhydrides and isocyanates are determined as their amide and urea derivatives using LC-MS. Four anhydrides, maleic anhydride (MA), phthalic anhydride (PA), tetrahydrophthalic anhydride (TA) and cis-hexahydrophthalic anhydride (HA) and 11 isocyanates could be separated in 9 minutes using gradient elution. Anhydride-DBA derivatives in standard solutions were quantified using LC with chemiluminescent nitrogen detection (CLND). Anhydride-DBA derivatives were found to be stable for at least two months when stored in acetonitrile or toluene in the freezer. The yield of DBA derivatives of anhydrides in the 0.01 M DBA in toluene-acetonitrile (7:3, v/v) was in the range of 70->95%. Using MS and negative electrospray ionisation (ES-) linear calibrations curves were obtained for the anhydrides with correlation coefficients ranging from 0.9970-0.9997. The instrumental detection limit for the anhydrides ranged from 10-30 fmol, based on a signal to noise root mean square (RMS) ratio of 3. Monitoring positive and negative ions simultaneously, both isocyanates and anhydrides could be determined as their DBA derivatives in the same chromatographic run. When air samples were collected during thermal degradation of different coated metal sheets both anhydrides and isocyanates were present in the same samples and all the studied anhydrides were found.     

长江南京段新兴污染物污染特征及风险评估

在长江南京段上游至下游依次布设6个采样点采集水样,使用固相萃取和LC-MS/MS相结合的方法对5种选定药物的质量浓度进行测定,并采用风险熵模型评估其生态风险。结果表明,6个采样点均检测到药物存在。其中,四环素、红霉素、罗红霉素和氯霉素的检出率为100%,最高检出值为10.29 ng/L(氯霉素)。与国内外其他地表水相比,长江南京段水中的药物质量浓度较低。生态风险评估结果表明,长江南京段水中5种药物的风险熵值均低于1,对水生生物不存在高风险。     

气相色谱-三重四极杆质谱法测定水中持久性有机氯污染物

建立了液液萃取一气相色谱三重四极杆质谱多反应监测同时测定水中16种持久性有机氯污染物的方法，考察了不同萃取剂不同体积对有机氯萃取效率的影响，确定了16种持久性有机氯化合物多反应监测模式（MRM）的最佳质谱条件。方法检出限为0.33 ~ 0.65 ng/L，以纯水为基体，加入16种不同浓度水平的持久性有机氯化合物作回收试验，测得回收率在80.2% ~ 103.6%之间，测定的相对标准偏差4.0% ~11.5%（n=7）。     

Atmospheric influence on the distribution of organic pollutants in the Guadalquivir River estuary, SW Spain

In the lower Guadalquivir river basin, a system stressed by a wide variety of anthropogenic activities, eight pesticides (four triazines, two chloroacetanilide herbicides, one organochlorine, and one organophosphorus insecticide); and four emerging pollutants (two personal care products, one organophosphorous flame retardant, and one xanthine alkaloid) were analyzed in river water during a 2-year monitoring program, and after rain episodes. Samples were extracted using the solid phase extraction (SPE) technique prior to determination of compounds using gas chromatograph coupled to a mass spectrometer detector. Except for caffeine, recoveries were mostly above 80 %, while limits of detection and quantification were in the low nanograms per liter level (except for dimethoate). Terbuthylazine, simazine (triazine herbicides), and dimethoate (organophosphorus insecticide), present in agrochemicals, were predominant in the river water, although concentrations were below the quality standards established by the EU Water-Framework-Directive. A general trend to increase concentration was observed after rain events, in particular for pesticides, possibly as a consequence of surface runoff.     

气相色谱—串联质谱法检测水中苯霜灵、甲霜灵、噁霜灵残留量

建立水中甲霜灵、苯霜灵、噁霜灵农药残留量的气相色谱—串联质谱(GC-MS/MS)的检测分析方法。样品采用乙腈提取、固相萃取(SPE)柱净化。采用GC-MS/MS分析时,三种农药在15 mim内完全分离并流出。添加浓度加标回收率为80.6%~88.4%,相对标准偏差(RSD)小于5.0%。在0.01~0.20 mg/L质量浓度范围之间线性关系良好(r~20.999 0)。该方法的灵敏度、精密度和准确度均满足农药残留分析要求,适用于水中的农药残留的快速筛查与定性、定量分析。     

On-line solid phase extraction and liquid chromatography/tandem mass spectrometry to quantify pharmaceuticals, pesticides and some metabolites in wastewaters, drinking, and surface waters

A simple on-line method was developed for the analysis of pharmaceuticals, pesticides and some metabolites in drinking, surface and wastewater samples. The technique is based on the use of on-line solid-phase extraction combined with liquid chromatography electrospray tandem mass spectrometry with positive electrospray ionization (LC-ESI(PI)-MS/MS). The injection of only 1 mL of filtered water sample is used with a total analysis time of 20 min, including the period required to flush the SPE cartridge with organic solvent and reconditioning the LC column. Method detection limits were in the range of 2 to 24 ng L(-1) for the compounds of interest, with recoveries from 87 to 110% in surface as well as wastewater samples. Matrix effects were observed for some compounds without exceeding more than 25%. All results displayed a good degree of reproducibility, with relative standard deviations (RSD) of less than 12% for all compounds. Moreover, at least 200 samples were analyzed without altering the performance of the pre-concentration column. This method was preferred over traditional off-line procedures because it minimizes tedious sample preparation, increases productivity and sample throughput. The analysis of various water and wastewater samples showed that caffeine, carbamazepine and atrazine could be detected in all the samples analysed and the selected compounds are always present in at least one of the sample types.     

加速溶剂萃取-气相色谱/串联质谱法测定土壤中20种有机氯农药

建立了用加速溶剂萃取法（ASE）提取、气相色谱-串联质谱法分析土壤中20种有机氯农药的方法。用正己烷和丙酮（1∶1,V/V）的混合溶剂为提取剂,萃取温度100℃,压力1 500 psi,静态提取10 min,循环提取2次,提取液经石墨化碳黑固相萃取柱净化,浓缩后进行GC-MS/MS测定,外标法定量。试验结果表明,采用串联质谱多反应监测模式,降低了背景干扰,当取5 g土壤时,有机氯农药的检出限在0.1~3.0μg/kg之间,低浓度水平（8μg/kg）的基体加标回收率为70.3%~134%,相对标准偏差〈23%。测定方法背景干扰低,灵敏度高,适合土壤中20种有机氯农药残留的同时测定。     

Detection of chlorophenolics in effluents from bleaching processes of rice-straw pulp

A number of chlorinated derivatives of phenols, catechols, guaiacols, syringaldehydes, have been detected and their concentrations estimated, using gas chromatography in the chlorination (C) and extraction (E) stage of spent bleach liquor generated in the laboratory by bleaching rice-straw soda pulp. The concentration of various compounds detected have also been compared with their reported 96LC50 values.     

Simultaneous determination of selected endocrine disrupter compounds in wastewater samples in ultra trace levels using HPLC-ES-MS/MS

An analytical procedure for the simultaneous determination of six selected endocrine disrupter compounds (EDCs: diltiazem, progesterone, benzyl butyl phthalate (BBP), estrone, carbamazepine (Cbz), acetaminophen) was developed by liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ES-MS/MS). All of the parameters for HPLC and ES-MS/MS systems including mobile phase composition, flow rate, and sample injection volume were optimized to obtain not only the best separation of species interested but also low detection limits. Reverse phase chromatography coupled to ES-MS/MS was used for the separation and detection of EDCs. Formic acid (0.10% ) and 5.0 mM ammonium formate were selected as mobile phase composition in gradient elution. Detection limits for diltiazem, progesterone, BBP, estrone, Cbz, and acetaminophen were found to be 0.13, 0.12, 0.04, 0.13, 0.12, and 0.05 ng/mL, respectively. Influent and effluents from three different wastewater treatment plants located in Ankara, i.e., rotating flat-sheet membrane unit, pilot type flat-sheet membrane unit located at METU Campus and samples from Ankara central wastewater treatment plant were analyzed for their EDCs contents under the optimum conditions.     

广东省南海市主干道气溶胶中多环芳烃(PAHs)的研究

气溶胶采样点位于广东省南海市桂江路边缘及两侧 ,采集时间为 2 4 h,连续采集三天。使用仪器为国产大体积采样器。同时在公园内设点采样 ,以作背景研究。样品经超声波抽提和层析柱分离得到正构烷烃、芳烃 (AHs)和极性组分等三种有机组分。对 PAHs进行 GC MS分析 ,气溶胶中具有较高含量的芴、菲、蒽、荧蒽、芘、苯并 [a]蒽、、苯并 [b]荧蒽、苯并 [k]荧蒽、苯并 [a]芘、茚并 [1 ,2 ,3-cd]芘、二苯并 [a,h]蒽、苯并 [g,h,i]等。通过 TSP研究认为 ,主干道的机动车排放和扬尘是气溶胶的主要来源 ,气候改变也是 TSP变化的另一重要因素。     

Optimizing a GC-MS method for screening of Stachybotrys mycotoxins in indoor environments

Presence of Stachybotrys chartarum in indoor environments has been linked to building-associated disease, however, the causative agents are unknown. Verrucarol (VER) and trichodermol (TRID) are hydrolysis products of some major S. chartarum mycotoxins, i.e. macrocyclic trichothecenes and trichodermin. We optimized gas chromatography-mass spectrometry (GC-MS) methods for detecting VER and TRID in S. chartarum-contaminated indoor environmental samples. Heptafluorobutyryl derivatives of both VER and TRID exhibited little MS fragmentation and gave much higher detection sensitivity (sub-picogram injected onto the GC column), both in GC-MS and GC-MSMS, than trimethylsilyl derivatives. Optimal detection sensitivity and specificity was achieved by combining chemical ionization and negative ion (NICI) detection with MSMS. With this method, VER and TRID were detected in building materials colonized by S. chartarum and TRID was demonstrated in dust settled in the breathing zone in a house where an inner wall was colonized. In summary, we have shown that NICI-GC-MSMS can be used to demonstrate mycotoxins in house dust in S. chartarum-contaminated dwellings.     

Detection of Methamidophos in Vegetables Using a Photometric Flow Injection System

A flow injection analysis (FIA) system using immobilized acetylcholinesterase (AChE) has been used for the detection of methamidophos in vegetable extracts. Methamidophos is one of the most commonly used organophosphate insecticides in South East Asia. AChE was immobilized onto magnetic particles; using a magnetic reactor, the particles could easily be separated from the test sample. Results show that complex matrices such as vegetable extracts have no inhibitory effect on AChE activity in the FIA system. The presence of methamidophos in the extracts caused AChE inhibition. The response could be followed as an inhibition curve and the inhibition constant calculated. Results show that using 85% AChE residual activity as the detection limit, methamidophos could be detected in lettuce and cabbage at 12 and 3 mg/kg vegetable material respectively. In a simulated field situation, cabbage leaves were spiked with 20 to 40 mg/kg methamidophos, homogenized and tested in the FIA system. The corresponding methamidophos levels predicted by the experimental results came very close to the known calculated values. Data presented here suggest that it is feasible to use this system to supplement the traditional chromatographic analysis methods for methamidophos analysis.     

Trace level determination of perchlorate in water matrices and human urine using ESI-FAIMS-MS

High-field asymmetric waveform ion mobility spectrometry (FAIMS) separates perchlorate from interfering isobaric ions of bisulfate and dihydrogenphosphate in the gas-phase. The use of a new FAIMS prototype and waveform generator, along with the use of a mixed carrier gas, in this electrospray ionisation (ESI)-FAIMS-mass spectrometry (MS) study gave a detection limit for perchlorate in a relatively "clean" matrix of tap water of 0.050 ppb. Flow injection analysis (FIA) of dilutions of fortified waste water, a fortified river water certified reference material (CRM; SLRS-4, National Research Council of Canada), and a fortified human urine Standard Reference Material (SRM; 2381, National Institute of Standards and Technology) gave detection limits of 0.37 ppb, 0.50 ppb, and 4.8 ppb, respectively, in the undiluted matrices.     

Identification of surfactant degradation products as toxic organic compounds present in sewage sludge

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