固相萃取–气相色谱–质谱法测定地表水中的三氯苯

建立固相萃取–气相色谱–质谱联用法测定地表水中三氯苯的方法,对固相萃取柱、洗脱剂、甲醇用量进行优化试验。在200 m L水样中加入20 m L甲醇,采用C18固相萃取柱,以正己烷为洗脱溶剂萃取水中的三氯苯,用气相色谱–质谱法测定。结果表明,三氯苯的三种同分异构体分离良好,1,2,3-三氯苯、1,2,4-三氯苯、1,3,5-三氯苯的质量浓度在2.0~100μg/L范围内与其色谱峰面积均呈良好的线性,线性相关系数分别为0.999 1,0.999 4,0.999 2,检出限分别为0.004,0.005,0.005μg/L,加标回收率为90.3%~96.5%,测定结果的相对标准偏差均小于2%(n=7)。该方法操作简便、快速,定性定量准确,有机试剂用量少,适用于地表水中三氯苯的检测。     

固相膜萃取/气相色谱-质谱法检测水体中痕量酚类化合物

建立了固相膜萃取/气相色谱-质谱法同时测定水体中多种痕量酚类化合物的分析方法。采用固相膜萃取技术提取水中的痕量酚类化合物,对洗脱液种类、洗脱液体积、水样初始p H值和洗脱速率等萃取条件进行优化,并用DB-5MS色谱柱分离,气相色谱-质谱法(GC-MS/SIM)进行定量测定。实验结果表明,在p H 2.0的初始条件下,选择10 m L乙酸乙酯-二氯甲烷混合溶液(体积比1∶1)作为洗脱剂,控制洗脱速率为1 m L/min时,酚类化合物的平均回收率高达82.3%~97.1%。在1~800μg/L质量浓度范围内,酚类化合物的峰面积与对应质量浓度呈良好线性关系,相关系数(r2)均在0.996以上,检出限均不大于0.017μg/L,相对标准偏差(RSD,n=8)为1.6%~4.3%。将方法应用于我国北江流域水样检测,结果可靠。该方法萃取时间短、灵敏度和准确度高、简单易行,满足实际水体中对痕量酚类化合物的检测要求,可显著提高水中痕量酚类化合物的分析效率。     

顶空固相微萃取-气相色谱-质谱法同时测定饮用水源水中24种VOCs

建立了同时测定饮用水源水中24种挥发性有机物(VOCs)的顶空固相微萃取-气相色谱-质谱法.用75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取柱顶空萃取水样中的VOCs,VOCs用气相色谱-质谱联用仪检测,采用内标法定量.对萃取柱涂层、样品盐度、萃取温度和萃取时间等样品前处理条件进行了优化,VOCs的检出限在0.03～0.31 μg/L之间,线性相关系数r＞0.996(二氯甲烷和三氯甲烷除外).对饮用水源水实际水样0.50μg/L和1.00 μg/L两个加标浓度水平的回收率进行了测定,三氯甲烷回收率均值分别为104％和142％,其余VOCs回收率分别为90.0％～120％和88.0％～110％,除二氯甲烷和三氯甲烷外,其余VOCs测定结果的相对标准偏差均小于15.0％(n=6).该方法适用于饮用水源水中挥发性有机物的监测分析.     

固相萃取–气相色谱–质谱联用法同时测定地表水中的四乙基铅和联苯胺

建立了固相萃取–气相色谱–质谱联用同时测定地表水中四乙基铅和联苯胺的方法。主要考察影响固相萃取的因素,包括固相萃取小柱的选择,水样p H值,以及洗脱溶剂对富集效果的影响。将水样调节至p H 12,经过HLB小柱富集、二氯甲烷洗脱后,采用DB–5MS柱程序升温分离,选择离子扫描模式,在10 min内完成两物质的测定。四乙基铅和联苯胺的质量浓度分别在20~200μg/L和40~400μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数分别为0.995 8和0.993 9。在最佳条件下富集1 000倍,四乙基铅和联苯胺的检出限分别为0.003μg/L,0.008μg/L。分别添加两浓度水平的四乙基铅和联苯胺到水样中,平均加标回收率为47.5%~89.4%,测定结果的相对标准偏差为5.4%–8.9%(n=6)。该方法简便、灵敏、快速,适合水源水中四乙基铅和联苯胺的常规检测。     

分散固相萃取-气相色谱-质谱法测定地表水中的3种拟除虫菊酯含量

采用分散固相萃取-气相色谱-质谱法测定地表水中的3种拟除虫菊酯。以HC-C_(18)萃取剂为固相萃取填料,以二氯甲烷为洗脱剂对水样进行分散固相萃取。萃取液在HP-5MS石英毛细管柱上分离,质谱中采用电子轰击离子源和选择离子监测模式。在最优条件下,3种拟除虫菊酯的质量浓度在0.05~10.0μg·L~(-1)范围内呈线性,检出限(3S/N)在0.001~0.005μg·L~(-1)之间,方法用于实际水样的分析,加标回收率在95.0%~99.8%之间,测定值的相对标准偏差(n=6)在4.3%~11%之间。     

大体积全自动固相萃取气相色谱–质谱法测定水中苯并芘

建立了全自动固相萃取–气相色谱–质谱联用测定水中苯并芘的方法。优化了全自动固相萃取条件,选择C8固相萃取柱萃取水样品中的苯并芘,样品中加入甲醇以增强苯并芘在萃取柱上的保留能力,采用正压大体积六通道同时进样,进样体积为1 000 m L,进样流量20 m L/min,使用二氯甲烷为洗脱溶剂,浓缩至0.5 m L。水中苯并芘的质量浓度在10~200μg/L范围内与其质谱响应值线性关系良好,相关系数为0.995,检出限为2 ng/L。在20~200μg/L加标水平上,苯并芘回收率为85.0%~94.5%,测定结果的相对标准偏差均小于6%(n=6)。该方法操作简单、测定结果准确,可用于水中苯并芘的测定。     

气相色谱-质谱法测定饮用水中的萘、联苯、蒽

建立了测定饮用水中萘、联苯、蒽的气相色谱-质谱方法。水中的萘、联苯、蒽被二氯甲烷萃取,萃取液浓缩后进行气相色谱-质谱分析,以峰面积外标法定量。萘、联苯、蒽的线性范围分别为0.001512μg/L、0.001~8μg/L和0.001~8μg/L。萘、联苯、蒽的线性相关系数均在0.999以上,低、高浓度样品的加标回收率为89.2%~98.5%,相对标准偏差为4.5%~8.7%。萘、联苯、蒽的最低检出浓度分别为0.0002、0.0001、0.0001μg/L。该法适合于饮用水中萘、联苯、蒽的测定。     

气相色谱法测定生活饮用水中2-氯苯酚和2-甲苯酚

采用固相萃取(SPE)小柱固相萃取,建立了生活饮用水中2-氯苯酚和2-甲苯酚的气相色谱检测方法。用盐酸调节水样至p H 5.0,用SPE小柱固相萃取后以乙酸乙酯洗脱,以CD-5色谱柱进行分离,氢火焰离子化检测器检测2-氯苯酚和2-甲苯酚的含量。2-氯苯酚和2-甲苯酚的质量浓度在2.00~40.0μg/L范围内与色谱峰面积线性关系良好,检出限分别为0.03,0.04μg/L;加标回收率分别为87.2%~93.9%,89.0%~94.8%;测定结果的相对标准偏差均小于2%(n=7)。该方法具有检出限低、操作简便等优点,适用于生活饮用水中2-氯苯酚和2-甲苯酚的监测分析。     

固相萃取-衍生化-气相色谱-质谱法测定水中类固醇类雌激素

采用固相萃取-衍生化-气相色谱-质谱法同时测定水中4种类固醇类雌激素雌酮(E1)、17β-雌二醇(E2)、17α-乙炔基雌二醇(EE2)、雌三醇(E3)。样品经Oasis HLB固相萃取柱,以丙酮为溶剂进行洗脱后,采用吡啶、N-甲基-N-三甲基硅基三氟乙酰胺于40℃衍生化20min后,采用气相色谱-质谱仪分析。E1、E2、EE2和E3的线性范围分别为5.00~500μg·L-1和10.0~500μg·L-1,4种类固醇类雌激素的检出限(3S/N)在1.5~3.0μg·L-1之间,测定下限(10S/N)在5.0~10μg·L-1之间;方法用于实际水样的分析,加标回收率在86.8%~93.8%之间,测定值的相对标准偏差(n=7)在7.1%~11%之间。     

全自动固相萃取及气相色谱-质谱联用法对环境水样中9种有机紫外防护剂及人工合成香料的测定

建立了一种全自动固相萃取/气相色谱-质谱联用测定环境水样中4种有机紫外防护剂和5种人工合成香料的方法.采用Cleanert C8柱对样品进行净化及浓缩,气相色谱-质谱法以选择离子流模式检测,外标法定量.在优化的实验条件下,9种目标化合物色谱峰分离良好,检出限和定量下限分别为5.15 ～85.2 ng/L和17.2 ～284 ng/L.在实际环境水样检测中的添加回收率为76% ～115%.添加0.20 μg/L混合标准的环境水样,其检测相对标准偏差为2.9% ～9.6%.     

The routine analysis of some specific isomers of polychlorinated biphenyl congeners in human milk

A mixture of 14 polychlorinated biphenyl (PCB) isomers of various congeners, representing approximately 70% of all human milk PCBs reported in the literature, was made up to identify and approximate their residues in human milk. Individual isomer levels varied from 5 to 103 nanograms per gram of milkfat with the 2,2',4,4',5,5'-hexachlorobiphenyl isomer as the major PCB contaminant of human milk. PCB isomer numbers 74, 118, 153, 138 and 180 made up approximately 75% of all PCBs as measured by this mixture. There was close agreement of total PCB isomer content in breast milk between electron capture gas chromatography and gas chromatographic mass spectrometry determinations. A major interference was encountered however for PCB isomer no. 52, whose residue level in the breast milk was approximately 3 X higher by gas liquid chromatography than by mass spectrometry.     

顶空固相微萃取气相色谱法测定浓海水中的氯酚

建立浓海水中氯酚的顶空固相微萃取气相色谱法检测方法。采用顶空固相微萃取对海水淡化排放的浓海水样品中2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)进行分离富集,气相色谱-电子捕获检测器(μECD)测定浓海水样品中2,4,6-TCP和PCP的含量。讨论了萃取时间、萃取温度、水样盐度等实验条件对富集效率的影响,确定了萃取时间为40 min,萃取温度为60℃。2,4,6-TCP,PCP的质量浓度在0.500~20.0μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数均大于0.999,2,4,6-TCP和PCP的检出限(2S/N)分别为0.055,0.128μg/L,测定结果的相对标准偏差为3.65%~11.4%(n=6),加标回收率为73.5%~119.0%。该方法快速,灵敏度高,适合于浓海水中氯酚的分析。     

A rapid screening method for routine congener-specific analysis of polychlorinated biphenyls in human serum by high-resolution gas chromatography with mass spectrometric detection

A screening method using gas chromatography/mass spectrometry in the single ion monitoring (SIM) mode for the routine congener-specific analysis of polychlorinated biphenyls (PCBs) in human serum has been developed and validated. A fast procedure incorporating both liquid-liquid and solid-phase extraction was used for clean up and enrichment. Interday and intraday precision and accuracy were assessed for the 12 congeners having dioxin-like activity and PCBs #180 and #170 by analyzing spiked samples on three subsequent days and using (13)C(12)-labelled analogues as internal standards. Furthermore, the relative errors for six non-dioxin-like congeners (PCBs #28, #52, #101, #138, #153 and #180) were measured by using certified reference materials, providing good accuracy at two different concentration levels. The limits of quantification and of detection were 0.5 and 0.2 micro g/L in serum for each congener, respectively. The method allows the chromatographic separation of at least 35 congeners and can therefore be applied to the routine monitoring of the general population for both dioxin-like and non-dioxin-like PCB congeners.     

气相色谱–质谱法测定地表水中硝基苯

建立吹扫捕集–气相色谱–质谱联用法测定地表水中硝基苯的方法。用吹扫捕集法对水样进行前处理,以HP–5弱极性毛细管柱(30 m×0.32 mm,0.25μm)进行分离,质谱法测定水中硝基苯的含量。硝基苯的质量浓度在0.00~60.0μg/L范围内与色谱峰面积线性关系良好,线性相关系数为0.999 4,方法的检出限为0.03μg/L。测定结果的相对标准偏差小于2%(n=7),地表水样品加标回收率在91.2%~96.5%之间。该方法操作简便,检出限低,精密度和准确度高,适用于地表水中硝基苯的测定。     

Solid‐phase microextraction of phthalate esters by a new coating based on a thermally stable polypyrrole/graphene oxide composite

A novel polypyrole/graphene oxide coating was made by the electrochemical polymerization of pyrrole in the presence of sodium dodecyl sulfate and graphene oxide on a platinum wire. The prepared fiber has shown a good thermal stability up to 300°C. The fiber was applied to the direct solid‐phase microextraction and gas chromatographic analysis of four phthalate esters. The effect of four parameters on gas chromatography peak area including extraction temperature, extraction time, injection temperature, and ionic strength were investigated. Under the optimized conditions, the detection limits were between 0.042 and 0.26 μg/L. The intraday and interday relative standard deviations obtained at 55 μg/L, using a single fiber, were 8.2–16% and 17.3–25.6%, respectively. The method was successfully applied to the analysis of phthalate esters in two real samples of boiling water in cheap disposable clear plastic drinking cups showing recoveries from 83 to 120%.     

Miniaturised sample preparation of fatty foodstuffs for the determination of polychlorinated biphenyls

A miniaturised analytical method allowing the exhaustive extraction of environmentally relevant polychlorinated biphenyls (PCBs) from fatty foodstuffs and the purification of the extracts in a single step has been developed. After dispersion of the freeze dried sample on silica modified with 44% (w/w) of sulphuric acid, the mixture was packed in a glass column on top of a multilayer silica column used for removal of the lipids and biogenic co-extracted material. Using this arrangement, a complete sample preparation can be accomplished by two successive 10 min static extractions with hexane followed by a brief dynamic step to ensure purging of the sample and sorbents. The analytical method showed a satisfactory performance, with recoveries of the endogenous PCBs studied in the 81-134% range of those found using a more conventional off-line procedure, even though as small an amount of sample as 0.1 g was used. Detection limits by gas chromatography with micro-electron capture detection (GC-ECD) were in all cases lower than 0.3 ng/g sample (freeze dried basis) and the repeatability of the complete analytical procedure better than 14% (except for PCB 167). When combined with GC and ion trap detection in the tandem mass spectrometry mode, the miniaturised method has been proved to be a valuable alternative to the more expensive high resolution mass spectrometry for fast screening of PCBs 77, 126, and 169, even if these congeners were not isolated from the bulk of PCBs.     

Magnetic micro‐solid‐phase extraction based on magnetite‐MCM‐41 with gas chromatography–mass spectrometry for the determination of antidepressant drugs in biological fluids

A new facile magnetic micro‐solid‐phase extraction coupled to gas chromatography and mass spectrometry detection was developed for the extraction and determination of selected antidepressant drugs in biological fluids using magnetite‐MCM‐41 as adsorbent. The synthesized sorbent was characterized by several spectroscopic techniques. The maximum extraction efficiency for extraction of 500 μg/L antidepressant drugs from aqueous solution was obtained with 15 mg of magnetite‐MCM‐41 at pH 12. The analyte was desorbed using 100 μL of acetonitrile prior to gas chromatography determination. This method was rapid in which the adsorption procedure was completed in 60 s. Under the optimized conditions using 15 mL of antidepressant drugs sample, the calibration curve showed good linearity in the range of 0.05–500 μg/L (r ² = 0.996–0.999). Good limits of detection (0.008–0.010 μg/L) were obtained for the analytes with good relative standard deviations of <8.0% (n  = 5) for the determination of 0.1, 5.0, and 500.0 μg/L of antidepressant drugs. This method was successfully applied to the determination of amitriptyline and chlorpromazine in plasma and urine samples. The recoveries of spiked plasma and urine samples were in the range of 86.1–115.4%. Results indicate that magnetite micro‐solid‐phase extraction with gas chromatography and mass spectrometry is a convenient, fast, and economical method for the extraction and determination of amitriptyline and chlorpromazine in biological samples.     

Determination of herbicides in environmental water samples by simultaneous in‐syringe magnetic stirring‐assisted dispersive liquid–liquid microextraction and silylation followed by GC–MS

An on‐line, fast, simple, selective, and sensitive method has been developed for the determination of three herbicides belonging to the following families: triazines (atrazine), chloroacetamide (alachlor), and phenoxy (2,4‐dichlorophenoxyacetic acid) in water samples. The method involves an in‐syringe magnetic stirring‐assisted dispersive liquid–liquid microextraction along with simultaneous silylation prior to their determination by gas chromatography with mass spectrometry. Extraction, derivatization, and preconcentration have been simultaneously performed using acetone as dispersive solvent, N‐methyl‐N‐tert‐butyldimethylsilyltrifluoroacetamide as derivatization agent and trichloroethylene as extraction solvent. After stirring for 180 s, the sedimented phase was transferred to a rotary micro‐volume injection valve (3 μL) and introduced by an air stream into gas chromatograph with mass spectrometry detector. Recovery and enrichment factors were 87.2–111.2% and 7.4–10.4, respectively. Relative standard deviations were in the ranges of 6.6–7.4 for intraday and 9.2–9.6 for interday precision. The detection limits were in the range of 0.045–0.03 μg/L, and good linearity was observed up to 200 μg/L, with R² ranging between 0.9905 and 0.9964. The developed method was satisfactorily applied to assess the occurrence of the studied herbicides in groundwater samples. The recovery test was also performed with values between 77 and 117%.     

Determination of coplanar and non-coplanar polychlorinated biphenyls in human serum by gas chromatography with mass spectrometric detection: electron impact or electron-capture negative ionization?

A time- and cost-saving method for the congener-specific analysis of polychlorinated biphenyls (PCBs) in human serum has been developed and validated. After two fast extraction and clean-up steps, analyses were performed using gas chromatography coupled with mass spectrometry with single ion monitoring (GC/SIM-MS), either in electron impact (EI) or electron-capture negative ionization (ECNI) mode. For the determination of dioxin-like congeners, an improvement in EI-MS sensitivity is desirable and use of NI is thus preferred. The procedure was validated for 12 dioxin-like congeners by analyzing spiked samples on three different days and using (13)C(12)-labelled analogues as internal standards. When using an NCI source, the limit of quantification was assessed at 0.01 microg/L, except for PCBs #77 and #81, which cannot be reliably detected below 0.05 microg/L. For the lower chlorinated non-dioxin-like congeners, NI offers less selectivity because of limited fragmentation. Electron impact ionization and electron-capture negative ionization mode can therefore be considered to be complementary for the determination of PCB congeners in the general population.     

液-液萃取气相色谱法测定地表水中痕量苯酚

建立了液-液萃取气相色谱法测定地表水中痕量苯酚的方法。用盐酸调节水样至pH2左右,以二氯乙烷-乙酸乙酯(体积比为2∶1)混合溶液为萃取剂,以CD-5色谱柱进行分离,氢火焰离子化检测器检测苯酚的含量。苯酚的质量浓度在1.00~20.0μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数r=0.999 3,检出限为0.03μg/L。样品加标回收率为93.0%~97.0%,测定结果的相对标准偏差小于2%(n=7)。该方法检出限低,精密度和准确度高,操作简便,适用于地表水中微量苯酚的分析。