固相微萃取/气相色谱-质谱法检测水中5种致嗅醛类

藻类代谢产生的醛类是导致水源水和生活饮用水腥味的主要原因,建立了使用固相微萃取/气相色谱-质谱法检测水中5种致嗅醛类的方法.检测结果表明,该方法线性范围宽,5种醛的检出限在4.3～15.6 ng/L,测定下限在17.2～62.4 ng/L,均远低于几种物质的嗅阈值.选取了纯水、生活饮用水和地表水进行加标回收实验,5种醛...     

固相萃取-气相色谱/质谱法测定水中硝基苯类化合物

采用固相萃取-气相色谱/质谱法测定水中硝基苯、硝基氯苯(间硝基氯苯、对硝基氯苯、邻硝基氯苯)、二硝基苯(对二硝基苯、间二硝基苯、邻二硝基苯)、2,4-二硝基甲苯、2,4-二硝基氯苯、2,4,6-三硝基甲苯10种硝基苯类化合物,保留时间及全扫描定性,外标法定量,定性定量准确,线性相关性强,干扰小。方法检出限为0.001-0.010μg/L,平均加标回收率在83.8-97.2%之间,RSD在1.2%-5.3%之间。     

固相萃取-气相色谱/质谱法测定地表水中硝基苯类化合物

采用固相萃取-气相色谱/质谱法测定水中硝基苯、硝基氯苯(间硝基氯苯、对硝基氯苯、邻硝基氯苯)、二硝基苯(对二硝基苯、间二硝基苯、邻二硝基苯)、2,4-二硝基甲苯、2,4-二硝基氯苯、2,4,6-三硝基甲苯等10种硝基苯类化合物,采用保留时间及全扫描定性,外标法定量,定性定量准确,线性相关性强,干扰小。该方法检出限为0.001～0.010μg/L,平均加标回收率在83.8%～97.2%之间,测定结果的RSD在1.2%～5.3%之间。     

顶空固相微萃取/气相色谱/质谱法测定水中三氯乙醛

将顶空固相微萃取与气相色谱/质谱仪联用,通过测定三氯乙醛在碱性条件下水解产物三氯甲烷,建立了一种测定地表水和生活饮用水中三氯乙醛化合物的新方法。研究了不同材质萃取头、加碱量、萃取温度和萃取时间等对萃取效率的影响,结果表明,该方法线性范围为0.1～10μg/L,相关系数(r)为0.999 4,检出限达到0.01μg/L。选取5.0μg/L和0.2μg/L两个浓度进行纯水加标实验,平均回收率分别为99.5%、96.7%,相对标准偏差分别为2.2%、7.4%。分别对饮用水和地表水水样进行了加标回收率实验,其平均回收率范围在92.5%～99.4%之间,相对标准偏差为2.1%～9.4%。该方法具有预处理时间短、灵敏度高、精密度和准确度好等特点,满足实际水样的检测要求。与国标GB/T 5750.10—2006中的气相色谱法相比,预处理时间由2.5 h缩短至0.5 h,分析效率显著提高,同时,灵敏度也比国标方法提高了100倍。     

固相萃取—气相色谱/质谱法测定水中7种农药

采用全自动固相萃取法提取水中7种农药,并采用气相色谱/质谱法检测,以保留时间和选择离子定性分析、菲-D10为内标物进行定量分析。结果表明:气相色谱/质谱法检测水中有机磷农药的最低检出限在1.0～2.4μg/L之间,全自动固相萃取测定有机磷农药的相对标准偏差是1.7%～7.2%,回收率在82.6%～92.0%之间。     

固相微萃取/气相色谱-质谱联用测定环境水中苯系物

对顶空进样和固相微苹取分别与气相色谱-质谱联用测定水中的苯系物的方进行了比较研究。对2种方法的线性、重复性、最小检出限进行了试验。测定结果表明，固相微苹取在灵敏度方面较好，利用固相微苹取方法进行了实际废水样的检测及回收率试验，结果较为满意。     

固相萃取-气相色谱质谱联用测定水中的乙草胺

本文建立了固相萃取-气相色谱质谱法测定地表水和生活饮用水中乙草胺的检测方法。采用了固相萃取提取净化样品,用气相色谱质谱法进行检测。试验结果表明,标准曲线的线性相关系数R为0.999,方法测定下限为0.015μg/L,加标回收率为96.0%～123%,相对标准偏差2.7%～7.6%。该方法操作简便,方法稳定性强,结果准确,适用于水中的乙草胺的检测。     

固相萃取/气相色谱/质谱法测定饮用水中毒死蜱

建立了检测饮用水中毒死蜱的固相萃取/气相色谱/质谱法,该方法对毒死蜱的测定下限可达0.000 6 mg/L,远低于国标法的0.002 mg/L。线性范围为0.5～5.0 mg/L,样品平均加标回收率在74.86%～86.14%之间,测定结果的相对标准偏差<5.4%。该方法简单、灵敏度高、准确、重现性好,可用于饮用水中痕量毒死蜱的测定。     

固相萃取气相色谱质谱法测定水中环氧七氯

建立了固相萃取气相色谱质谱法测定水中环氧七氯的方法。试验结果得到,环氧七氯标准曲线方程为Y=4991X-9.861,相关系数R=0.9999,检出限为0.02μg/L,加标回收率在75.0%～85.0%之间,平均回收率为79.2%,相对标准偏差为4.75%。     

顶空固相微萃取-气相色谱串联质谱法检测水中30种异味物质

采用顶空-箭形固相微萃取-气相色谱-三重四极杆质谱技术(HS-SPME ARROW-GC-MS/MS),建立了一种快速测定水中30种异味物质的方法.对顶空固相微萃取的参数进行了优化,确认了最优实验条件,NaCl浓度为0.3g/mL、萃取温度为50℃、萃取时间为30min、解吸时间为120s.在优化实验条件下,方法线性良...     

易燃液体放火案件物证分析技术的研究进展

将易燃液体放火案件中的火场物证分为液态物证、固态物证和气态物证三大类,分别总结介绍其特点、采集方法。结合国内外的标准规范,分别阐述易燃液体放火案件物证的提取技术,包括ASTM易燃液体残留物提取方法及其优化方法和分析鉴定技术,包括紫外光谱法、气相色谱法、高效液相色谱法和气相色谱/质谱联用法等的特点和研究进展。     

Chemical characterization of industrial wastewaters by gas chromatography-mass spectrometry

Organic pollutants in seven industrial wastewaters being discharged into the Calcasieu River in Louisiana were identified by gas chromatography-mass spectrometry. Discharge of compounds not indicated from the manufacturer's lists of products and raw materials were revealed. Chemical characterization provided information beyond that obtainable from traditional pollution measurements and information especially suitable for pollution legislation enforcement.     

用电子鼻和SPME-GC-MS分析鲍鱼熟制前后挥发性风味物质的变化

为了揭示熟制鲍鱼主要特征气味的成因,采用电子鼻及固相微萃取结合气-质联用(SPME-GCMS),对熟制过程中皱纹盘鲍Haliotis discus hannai香气差异和挥发性成分变化进行了研究。结果表明:电子鼻能够灵敏地检测到熟制鲍鱼的香气变化,经PCA分析发现,熟制鲍与生鲍整体气味有显著差异;GCMS分析表明,熟制前后鲍鱼的挥发性成分发生明显变化,从生鲍和熟制鲍中分别鉴定出42种和61种风味物质,主要物质有醇、醛、酮、烃、酯、酸、芳香族、含氮化合物、酚类;生鲍中挥发性风味物质含量较高的为苯甲醛(68.15%)和1-辛烯-3-醇(9.22%),熟制鲍中挥发性风味物质含量较高的为2,3-丁二醇(22.80%)和(2R,3R)-(-)-2,3-丁二醇(19.84%)。研究表明,运用电子鼻和固相微萃取结合气-质联用(SPME-GC-MS)能够很好地分析鲍鱼熟制前后气味的变化。     

Determination of phenol in the Bangsai River water of Bangladesh by gas chromatography-mass spectrometry

A simple, sensitive and rapid gas chromatography-mass spectrometry (GC-MS) method is proposed for the analysis of some environmentally important highly toxic phenols in water. The concentration level of phenol was determined in water at the sampling stations of Savar, Dhaka Export Processing Zone (DEPZ) and Bank Colony of the Bangsai River, Bangladesh. Water samples were collected from different depth of the sampling stations. The phenolic compounds were extracted with dichloromethane, which was further preconcentrated by evaporation. Different concentrations of toxic phenol were obtained in the river water at the various sampling stations. The concentration of highly toxic phenol was found in the range of 0.01–0.998 μg L⁻¹. This method could permit the analysis of water for phenol as well as phenolic derivatives with detection limit as low as 100 ng L⁻¹.     

Characterization of naphthenic acids in oil sands wastewaters by gas chromatography-mass spectrometry

The water produced during the extraction of bitumen from oil sands is toxic to aquatic organisms due largely to a group of naturally occurring organic acids, naphthenic acids (NAs), that are solubilized from the bitumen during processing. NAs are a complex mixture of alkyl-substituted acyclic and cycloaliphatic carboxylic acids, with the general chemical formula CnH(2n + Z)O2, where n is the carbon number and Z specifies a homologous family. Gas chromatography-electron impact mass spectrometry was used to characterize NAs in nine water samples derived from oil sands extraction processes. For each sample, the analysis provided the relative abundances for up to 156 base peaks, with each representing at least one NA structure. Plotting the relative abundances of NAs as three-dimensional bar graphs showed differences among samples. The relative abundance of NAs with carbon numbers < or = 21 to those in the "C22 + cluster" (sum of all NAs with carbon numbers > or = 22 in Z families 0 to -12) proved useful for comparing the water samples that had a range of toxicities. A decrease in toxicity of process-affected waters accompanied an increase in the proportion of NAs in the "C22 + cluster", likely caused by biodegradation of NAs with carbon numbers of < or = 21. In addition, an increase in the proportion of NAs in the "C22 + cluster" accompanied a decrease in the total NAs in the process-affected waters, again suggesting the selective removal of NAs with carbon numbers of < or = 21. This is the first investigation in which changes in the fingerprint of the NA fraction of process-affected waters from the oil sands operations has corresponded with measured toxicity in these waters.     

Multi-walled carbon nanotubes as solid-phase extraction adsorbents for determination of atrazine and its principal metabolites in water and soil samples by gas chromatography-mass spectrometry

A novel, simple, cost-effective, and sensitive method was developed for the determination of atrazine and its principal metabolites namely deisopropyl-atrazine (DIA) and deethyl-atrazine (DEA) in water and soil samples using multi-walled carbon nanotubes as solid-phase extraction (SPE) adsorbents coupled with gas chromatography-mass spectrometry (GC-MS). Several condition parameters, such as sample loading flow-rate, eluent and elution volume, extractant and ratio of extraction solvent to sample, were optimized to achieve good sensitivity and precision for the extraction and elution of analytes. A methanol/water solution (50%, v/v) was used to extract atrazine, DIA and DEA from soil. After the extracts went through SPE cartridges (packed with multi-walled carbon nanotubes) at a flow-rate of 4 mL min(-1), the analytes were eluted by 4 mL ethyl acetate at the rate of 1 mL min(-1) under a vacuum pump. The limit of detection (S/N=3) of the proposed method was 0.02 microg kg(-1) for atrazine in water and 0.3 microg kg(-1) in soil; 0.04 microg kg(-1) for DIA in water and 1.0 microg kg(-1) in soil; 0.05 microg kg(-1) for DEA in water and 0.8 microg kg(-1) in soil. Mean recoveries were in the range of 72.27-109.68%, and the reproducibility was accepted (RSD <13%) under the optimum conditions. This developed method was applied to determine the analytes in real environmental samples, and the concentrations of atrazine were 0.77-10.83 microg kg(-1), while DEA and DIA were not detected.     

Determining estrogenic steroids in Taipei waters and removal in drinking water treatment using high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry

River water and wastewater treatment plant (WWTP) effluents from metropolitan Taipei, Taiwan were tested for the presence of the pollutants estrone (E1), estriol (E3), 17beta-estradiol (E2), and 17alpha-ethinylestradiol (EE2) using a new methodology that involves high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry. The method was also used to investigate the removal of the analytes by conventional drinking water treatment processes. Without adjusting the pH, we extracted 1-L samples with PolarPlus C18 Speedisks under a flow rate exceeding 100 mL/min, in which six samples could be done simultaneously using an extraction station. The adsorbent was washed with 40% methanol/60% water and then eluted by 50% methanol/50% dichloromethane. The eluate was concentrated until almost dry and was reconstituted by 20 microL of methanol. Quantitation was done by LC-MS/MS-negative electrospray ionization in the selected reaction monitoring mode with isotope-dilution techniques. The mobile phase was 10 mM N-methylmorpholine aqueous solution/acetonitrile with gradient elution. Mean recoveries of spiked Milli-Q water were 65-79% and precisions were within 2-20% of the tested concentrations (5.0-200 ng/L). The method was validated with spiked upstream river water; precisions were most within 10% of the tested concentrations (10-100 ng/L) with most RSDs<10%. LODs of the environmental matrixes were 0.78-7.65 ng/L. A pre-filtration step before solid-phase extraction may significantly influence the measurement of E1 and EE2 concentrations; disk overloading by water matrix may also impact analyte recoveries along with ion suppression. In the Taipei water study, the four steroid estrogens were detected in river samples (ca. 15 ng/L for E2 and EE2 and 35-45 ng/L for E1 and E3). Average levels of 19-26 ng/L for E1, E2, and EE2 were detected in most wastewater effluents, while only a single effluent sample contained E3. The higher level in the river was likely caused by the discharge of untreated human and farming waste into the water. In the drinking water treatment simulations, coagulation removed 20-50% of the estrogens. An increased dose of aluminum sulfate did not improve the performance. Despite the reactive phenolic moiety in the analytes, the steroids were decreased only 20-44% of the initial concentrations in pre- or post-chlorination. Rapid filtration, with crushed anthracite playing a major role, took out more than 84% of the estrogens. Except for E3, the whole procedure successfully removed most of the estrogens even if the initial concentration reached levels as high as 500 ng/L.     

Determination of organoarsenic warfare agents in sediment samples from Skagerrak by gas chromatography-mass spectrometry

In 1945 the Norwegian authorities gave permission to scuttle ships loaded with captured chemical ammunition on board in an area approximately 14x4 km in size, 25 nautical miles south-east of Arendal. An investigation was carried out in 2002 to inspect four wrecks by using a remote-operated vehicle with video cameras. The Norwegian Defence Research Establishment (Forsvarets forskningsinstitutt, FFI) carried out the project on behalf of the Norwegian Pollution Control Authority (SFT). Sediment samples were collected at eight positions around each wreck. One of the wrecks was broken up into several smaller parts. Here sediments were collected at one additional position close to one of the parts. From each position, at least two sediment cores were taken up to the surface. One of the cores from each position was sliced into three parts that were immediately frozen. The other whole cores were frozen on board the ship and transported back to the laboratory in a freezer. In total, sediment samples from 33 different locations were collected and analysed for organoarsenic warfare agents and some of their decomposition products by gas chromatography-mass spectrometry (GC-MS) after derivatisation with 1-propanethiol. Most of the identified organoarsenic compounds found in the sediment samples are parts of the arsine oil mixture produced by Germany during World War II. The compounds were found both close to the wreck and at a somewhat longer distance from the wrecks. The highest concentrations were found in a sediment sample collected close to a bomb seen on the seabed. The organoarsenic warfare agents adamsite or lewisite were not found in any of the samples. Lewisite is not reported to have been produced during World War II, but was nevertheless looked for in the samples.     

Identification of chlorinated styrenes in cormorant tissues by a computerized gas chromatography-mass spectrometry system

The results of a study concerning the identification of three unknown compounds which were detected in extracts of cormorant tissue are reported. From these results it has been concluded that one of the compounds is octachlorostyrene. It is highly probable that the other two compounds are heptachlorostyrenes. Octachlorostyrene was also detected in fish, seals and various other aquatic bird species.     

An investigation of organic compounds in night soil and the treated water by gas chromatography-mass spectrometry

Although the rates of removal of BOD and other indicators have been studied for the evaluation of night soil^* treatment plant, there is no report about organic compounds. In order to identify trace amounts of organic compounds in night soil treatment plant at each process stage, the organic compounds in the night soil and in the treated water were subjected to anaerobic methods and analyzed by gas chromatography—mass spectrometry. Cholesterol and coprostanol as fecal sterols, indoles as odor substances and dichlorobenzene, cresol and phenol as disinfectants used in toilets were identified in the sample of night soil. As a result of anaerobic treatment the fecal sterols were degraded, oxindole remained, and phenylacetic acid was identified as a metabolite from tryptophan. These organic compounds were completely degraded by the aerobic treatment when phthalates and adipate were identified in the effluent.