吹扫捕集-气相色谱质谱法分析土壤和沉积物中挥发性有机物

采用吹扫捕集-气相色谱质谱法对土壤和沉积物中挥发性有机物进行分析,优化了实验条件,所有物质的相对标准偏差小于5.0％,土壤样回收率在78.2％ ～99.8％之间,沉积物样的回收率在55.2％～95.2％之间.     

土壤和河流沉积物中六六六和滴滴涕残留的测定

采用密闭微波提取、超声波提取、索氏提取对土壤和河流沉积物进行前处理,提取液经弗罗里硅土柱净化或浓硫酸净化.通过回收率实验和精密度实验对三种提取方法和两种净化方法进行比较,建立了微波提取土壤和河流沉积物中六六六和滴滴涕,浓硫酸净化,气相色谱一质谱测定的分析方法,方法回收率在84%～110%之间,精密度(RSD)在2.8%～9.9%之间.采用该方法对阜阳市废弃农药厂周围的土壤和河流沉积物中六六六和滴滴涕进行了监测.     

吖啶黄褪色分光光度法测定环境水样中的亚硝酸盐氮

利用在酸性介质中，吖啶黄与亚硝酸根反应并在波长436啪处的吸光度与亚硝酸根浓度呈线性关系，提出并建立了测定亚硝酸盐氮的新方法。亚硝酸盐氮含量在0～300μg/L内符合比尔定律。本方法的检出限为0．004mg/L。实验室内相对标准偏差不超过2．7％，加标回收率在93％～112％之间。     

水中总氮快速测定实验方法研究

针对现行总氮标准测定方法存在的操作繁琐、耗时长等缺点,采用COD消解加热器消解代替原标准方法中的高温高压消解步骤,以简化实验步骤、缩短用时,建立快速测定水中总氮的分析方法.通过对本方法进行平行实验、加标回收实验以及与标准方法的对比实验等分析实验结果,方法的线性范围为0 ～ 4.00 mg/L,平均加标回收率是102.3％,标样平行实验的相对标准偏差是1.05％,准确度、精确度和回收率均达到标准要求,方法具有一定的推广价值.     

液液萃取-气相色谱-质谱法同时测定饮用水中的酞酸酯、百菌清和联苯胺

建立了液液萃取-气相色谱-质谱（LLE -GC/MS）同时测定饮用水中的6种酞酸酯类化合物、百菌清和联苯胺的方法。选用3种有机溶剂进行萃取，筛选出回收率高、操作简单的前处理方法，萃取后经气相色谱-质谱分析。方法表明：8种物质线性良好，相关系数为0．9978～0．9995，用二氯甲烷萃取回收率最佳，回收率在90．1％～118％之间，相对标准偏差在0．24％～7．21％之间。     

液-液萃取-气相色谱法同时测定水中吡啶、松节油和苯胺

研究建立了气相色谱法同时测定水中吡啶、松节油和苯胺的方法.采用二氯甲烷萃取,萃取后直接进行色谱分离分析,3种物质能够有效分离.吡啶、松节油和苯胺的水中最低检测浓度分别为0.009、0.009、0.004mg/L,样品添加平均回收率为89％～114％,平行6次精密度实验,相对标准偏差小于6.5.实验结果表明,气相色谱法简单、快速、准确,适用于水中吡啶、松节油和苯胺的测定.     

气相色谱法测定空气中丙烯酸酯

讨论了用气相色谱仪测定被污染空气中丙烯酸甲酯、丙烯酸乙酯、甲基丙烯酸甲酯、丙烯酸丁酯的方法条件。方法检出下限在６ｎｇ范围,相对标准偏差为１４～６９％,回收率为９０６～１１０５％。实验还显示丙烯酸酯污染空气问题不容忽视。     

超高效液相色谱-串联质谱法测定饮用水源水中磺胺类抗生素

建立了饮用水源水中6种磺胺类抗生素的固相萃取超高效液相色谱-串联质谱分析方法.优化了固相萃取、液相色谱、串联质谱多反应监测模式检测的相关参数；采用外标法定量,并对实际饮用水源水样品的基体效应进行评价.实验结果表明,目标化合物在1.0～100.0 μg/L范围内线性关系良好,仪器检出限为0.03～0.54 μg/L,实际水样的加标回收率60％ ～ 75％.该本方法灵敏度高,选择性好,外标法定量准确性较好,但实际样品存在一定的基体抑制效应.     

动态顶空气相色谱法测定水中极性水溶性有机物

采用动态顶空气相色谱FID法测定水中乙醛、丙酮、甲醇、丙烯醛、丙烯腈、乙腈、吡啶等7种极性水溶性有机物，通过优化动态顶空条件，使该方法在0．157mg／L～7．92mg!L之间线性良好。方法检出限在0．008mg／L～0．048mg／L之间，空白水样的加标回收率为103％～111％，RSD为5．4％～8．7％。用该方法测定某制药企业排口污水和地表水，只有污水中甲醇、乙腈、吡啶有响应值。     

吹扫—捕集/气相色谱法测定水中挥发性卤代烃

建立了吹扫—捕集 /气相色谱 /电子捕获检测器联用测定水中 5种挥发性卤代烃分析方法 ,且按国家水质分析标准方法 (GB/T 1 71 3 0 -1 997)所确定的三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯、三溴甲烷 5种挥发性卤代烃进行实验 ,采用 Supelcoport担体层析柱对去离子水处理 ,所获得的纯水无色谱干扰峰 ,本法按国家水质分析标准方法列出的 5种挥发性卤代烃进行测定在国内尚未见报导。当纯水的进样体积为 5 .0 ml时 ,其最低检出浓度为 1× 1 0 - 2～ 6× 1 0 - 4(μg/L)之间 ;相对误差在 1 .1 %～ 2 .4%之间 ;加标回收率在 82 .5 %～ 1 0 8%之间 ;相关系数在 0 .9980～ 0 .9999之间。可快速、高灵敏度、简便、准确、精密地测定水中 5种挥发性卤代烃 ,本法适用于饮用水和地表水中挥发性卤代烃的测定     

Occurrence of naproxen,ibuprofen, and diclofenac residues in wastewater and river water of KwaZulu-Natal Province in South Africa

The present paper reports a detailed study that is based on the monitoring of naproxen, ibuprofen, and diclofenac in Mbokodweni River and wastewater treatment plants (WWTPs) located around the city of Durban in KwaZulu-Natal Province of South Africa. Target compounds were extracted from water samples using a multi-template molecularly imprinted solid-phase extraction prior to separation and quantification on a high-performance liquid chromatography equipped with photo diode array detector. The analytical method yielded the detection limits of 0.15, 1.00, and 0.63 μg/L for naproxen, ibuprofen, and diclofenac, respectively. Solid-phase extraction method was evaluated for its performance using deionized water samples that were spiked with 5 and 50 μg/L of target compounds. Recoveries were greater than 80% for all target compounds with RSD values in the range of 4.1 to 10%. Target compounds were detected in most wastewater and river water samples with ibuprofen being the most frequently detected pharmaceutical. Maximum concentrations detected in river water for naproxen, ibuprofen, and diclofenac were 6.84, 19.2, and 9.69 μg/L, respectively. The concentrations of target compounds found in effluent and river water samples compared well with some studies. The analytical method employed in this work is fast, selective, sensitive, and affordable; therefore, it can be used routinely to evaluate the occurrence of acidic pharmaceuticals in South African water resources.     

Performance evaluation of a sorbent tube sampling method using short path thermal desorption for volatile organic compounds

Air sampling, using sorbents, thermal desorption and gas chromatography, is a versatile method for identifying and quantifying trace levels of volatile organic compounds (VOCs). Thermal desorption can provide high sensitivity, appropropriate choices of sorbents and method parameters can accommodate a wide range of compounds and high humidity, and automated short-path systems can minimize artifacts, losses and carry-over effects. This study evaluates the performance of a short-path thermal desorption method for 77 VOCs using laboratory and field tests and a dual sorbent system (Tenax GR, Carbosieve SIII). Laboratory tests showed that the method requirements for ambient air sampling were easily achieved for most compounds, e.g., using the average and standard deviation across target compounds, blank emissions were < or = 0.3 ng per sorbent tube for all target compounds except benzene, toluene and phenol; the method detection limit was 0.05 +/- 0.08 ppb, reproducibility was 12 +/- 6%, linearity, as the relative standard deviation of relative response factors, was 16 +/- 9%, desorption efficiency was 99 +/- 28%, samples stored for 1-6 weeks had recoveries of 87 +/- 9%, and high humidity samples had recoveries of 102 +/- 12%. Due to sorbent, column and detector characteristics, performance was somewhat poorer for phenol groups, ketones, and nitrogen containing compounds. The laboratory results were confirmed in an analysis of replicate samples collected in two field studies that sampled ambient air along roadways and indoor air in a large office building. Replicates collected under field conditions demonstrated good agreement except for very low concentrations or large (> 41 volume) samples of high humidity air. Overall, the method provides excellent performance and satisfactory throughput for many applications.     

气相色谱-串联质谱法测定水中痕量有机磷农药和甲萘威

采用二氯甲烷萃取水样，气相色谱-串联质谱法同时测定水中有机磷农药和甲萘威。试验表明：方法在20．0μg/L ～1000μg/L范围内，各目标化合物线性良好；方法检出限为0．004μg/L～0．01μg/L；对实际水样进行3个质量浓度水平的加标回收试验，回收率在71．8％～94．5％之间，RSD为3．7％～8．5％，满足水中痕量有机磷农药和甲萘威的测定要求。     

直接进样-热脱附-GC-MS快速测定大气细颗粒物中有机示踪物

建立了直接进样-热脱附-GC-MS快速测定细颗粒物中甾烷类和藿烷类有机示踪物的方法。经实验条件优化,13种目标化合物的线性回归方程的相关系数均在0.990以上,空白加标回收率为81.4%~102.3%,实际样品加标回收率为79.1%~112.9%,相对标准偏差小于13.2%。当采样体积为24 m~3时,各目标化合物的检出限为0.008~0.084 ng/m~3,方法灵敏度高。利用该方法测定了北京城区采暖季和非采暖季PM2.5实际样品,结果表明:各目标物均有检出,且采暖季的甾烷类和藿烷类化合物的总量均明显高于非采暖季。该方法无需复杂的前处理和有机溶剂,操作简便快捷,在颗粒物中非极性化合物的快速检测方面具有很大的应用价值。     

Development and comparison of methods using MS scan and selective ion monitoring modes for a wide range of airborne VOCs

Adsorbent sampling with analysis by thermal desorption, gas chromatography and mass spectrometry (TD/GC/MS) offers many advantages for volatile organic compounds (VOCs) and thus is increasingly used in many applications. For environmental samples and other complex mixtures, the MS detector typically is operated in the scan mode to aid identification of co-eluting compounds. However, scan mode does not achieve the optimal sensitivity, thus compounds occurring at low concentrations may not be detected. This paper develops and evaluates the application of a more sensitive TD/GC/MS method using selective ion monitoring (SIM) that is applicable to VOC mixtures found in ambient and indoor air. Based on toxicity and prevalence, 94 VOCs (including terpenes, aromatic, halogenated and aliphatic compounds) were selected as target compounds. Two analytical methods were developed: a conventional full scan method for ions from 29 to 270 m/z; and a SIM method using 16 time windows and different ions selected for the compounds in each window. Both methods used the same Tenax GR adsorbent sampling tubes, TD and GC parameters, and target and qualifier ions. Laboratory tests determined calibrations, method detection limits (MDLs), precisions, recoveries and storage stability. Field tests compared scan and SIM mode analyses for duplicate samples of indoor air in 51 houses and outdoor air at 41 sites. Statistical analyses included the development of error/precision models. The laboratory tests showed that most compounds demonstrated excellent precision (<10% for concentrations exceeding approximately 0.5 microg m(-3)), good linearity, near identical calibrations for scan and SIM modes, a wide dynamic range (up to 1500 microg m(-3)), and negligible storage losses after 1 month (7 compounds showed moderate losses). SIM mode MDLs ranged from 0.004 to 0.27 microg m(-3), representing a modest (1.1 to 22-fold) improvement compared to scan mode. However, in field tests the SIM method detected significantly more compounds (e.g., styrene and chloroform). Error models fit most compounds and allow quantification of errors at selected percentiles. Overall, while the new SIM method is somewhat time-consuming to develop, it offers greater sensitivity and maintains the high selectivity of traditional scan methods.     

Solid-phase extraction followed by liquid chromatography-time-of-flight-mass spectrometry to evaluate pharmaceuticals in effluents. A pilot monitoring study

The present work provides a multi-residue analytical method for determining a selection of 20 pharmaceuticals from diverse therapeutical classes in hospital effluent wastewater. The method is based on the simultaneous extraction of the target compounds by solid phase extraction (SPE), followed by liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) analysis. Using TOF-MS, accurate mass measurements within 2 ppm error were obtained for most of the pharmaceuticals studied. Empirical formula information can be obtained by this method, allowing the unequivocal identification of the target compounds in the samples. Validation studies showed that LC-TOF-MS analysis is a valuable new tool for identification and quantification of pharmaceuticals in wastewater. Recoveries, using Oasis HLB cartridges at pH 7, were higher than 75% for all pharmaceuticals, except for ranitidine, 4-methylaminoantipyrine (4-MAA), cefotaxime and omeprazole, which needed specific pH conditions for their extraction. Linearity of response over two orders of magnitude was demonstrated (r > 0.99). Matrix effects resulting in suppression of the response were observed. For most of the compounds ion suppression was less than 39%, except for metronidazole, carbamazepine 10,11-epoxide, naproxen and erythromycin, where the signal suppression was 42%, 59%, 46% and 95%, respectively. A simple and effective approach to minimize or avoid matrix interferences was the 1 : 4 dilution of the SPE extracts. Method detection limits (MDLs) and quantification limits (MQLs) ranged between 4-115 ng l(-1) and 14-384 ng l(-1), respectively. The precision of the method, calculated as relative standard deviation (RSD), ranged from 1.1-19.8% and 1.7-21.7% for intra- and inter-day, respectively. The developed analytical method was applied to the analysis of hospital effluent wastewater during a survey study. 18 of the 20 pharmaceuticals studied were detected at concentration levels of microg l(-1), reaching in some cases concentrations over 100 microg l(-1), and in the case of the analgesic and antipyretic dipyrone metabolite, higher than 1000 microg l(-1).     

Development of a sampling method for the simultaneous monitoring of straight-chain alkanes, straight-chain saturated carbonyl compounds and monoterpenes in remote areas

Studies have shown that biogenic compounds, long chain secondary compounds and long lifetime anthropogenic compounds are involved in the formation of organic aerosols in both polluted areas and remote places. This work aims at developing an active sampling method to monitor these compounds (i.e. 6 straight-chain saturated aldehydes from C6 to C11; 8 straight-chain alkanes from C9 to C16; 6 monoterpenes: α-pinene, β-pinene, camphene, limonene, α-terpinene, & γ-terpinene; and 5 aromatic compounds: toluene, ethylbenzene, meta-, para- and ortho-xylenes) in remote areas. Samples are collected onto multi-bed sorbent cartridges at 200 mL min(-1) flow rate, using the automatic sampler SyPAC (TERA-Environnement, Crolles, France). No breakthrough was observed for sampling volumes up to 120 L (standard mixture at ambient temperature, with a relative humidity of 75%). As ozone has been shown to alter the samples (losses of 90% of aldehydes and up to 95% of terpenes were observed), the addition of a conditioned manganese dioxide (MnO(2)) scrubber to the system has been validated (full recovery of the affected compounds for a standard mixture at 50% relative humidity--RH). Samples are first thermodesorbed and then analysed by GC/FID/MS. This method allows suitable detection limits (from 2 ppt for camphene to 13 ppt for octanal--36 L sampled), and reproducibility (from 1% for toluene to 22% for heptanal). It has been successfully used to determine the diurnal variation of the target compounds (six 3 h samples a day) during winter and summer measurement campaigns at a remote site in the south of France.     

Determination of organophosphorus pesticides and related compounds in water samples by membrane extraction and gas chromatography

A membrane extraction-gas chromatography method was developed fordetermination of organophosphorus pesticides and related compounds including methamidophos, DDVP, dimethoate, methyl parathion, parathion, thiophosphoric acid trimethyl ester, and thiophosphoramidic acid dimethyl ester in water samples. In thismethod, surface-modified acetic cellulose membranes were used to extract the target analytes in water samples, the extracted analytes were back-extracted into a small amount of methanol, andgas chromatography with pulsed flame photometric detector (GC-PFPD) was used to determine the concentrations of targetanalytes in the extracts. The recoveries obtained for thetarget analytes spiked into the water samples ranged from 66to 94%. The method detection limit for each target analyte was 0.05 g L^-1. The method developed in this study had shown the advantages of being cheap, simple, fast, and reliable. It had been used successfully to determine the concentrations of target analytes in river water samples.     

SPE-GC-MS/MS法测定水源水中多种有机氯EDCs

采用C 18柱固相萃取(SPE)-三重四级杆气相色谱-质谱法同时测定水中18种含有机氯的环境内分泌干扰物,方法在0.500μg/L^100μg/L范围内线性良好,方法检出限为0.04 ng/L^0.8 ng/L,空白水样的加标回收率为61.3%~108%,6次测定结果的RSD为3.8%~18.0%。将该方法用于饮用水源水监测,18种目标化合物的测定值为未检出~1.5 ng/L,平均加标回收率为71.9%~109%,平行测定结果的RSD<15%。     

UPLC-MS/MS法同时测定地表水中多种有机污染物

采用超高效液相色谱-串联质谱法直接进样测定地表水中26种有机污染物,通过优化试验条件,使各目标化合物在1.00μg/L^100μg/L范围内线性良好,相关系数(r 2)>0.995,方法检出限为0.003μg/L^1.0μg/L。将该方法用于地表水样的测定,加标回收率为79.0%~120%,6次测定结果的RSD均<15%。