固相萃取采样和气相色谱-质谱检测液化石油气中的芳烃杂质（英文）

建立石墨化碳(GCB)为吸附剂的动态采样系统,可实现液化石油气(LPG)中芳烃杂质的采样和同步萃取富集。LPG中的芳烃杂质(苯、甲苯、二甲苯、苯乙烯和萘)被快速捕集后,进行气相色谱-质谱(GC-MS)定性定量分析。与C18和苯乙烯二乙烯苯吸附剂(PS-DVB)相比,GCB填充柱对芳烃杂质的萃取效率最高。评价了基于GCB填充柱采样的吸附效率、重现性和贮存稳定性。采样和分析方法对氮气模拟气流中8种芳烃的定量分析线性范围为15~1 000μg/m~3。所开发的方法具有回收率高(92.9%~109.0%)、检出限低(1.0~6.2μg/m~3)、准确性好(相对标准偏差为0.6%~5.8%)和准确度高(标准偏差为0.8%~8.2%)等优点。     

Multicomponent analysis of volatile organic compounds in water by automated purge and trap coupled to gas chromatography-mass spectrometry

Experiments and molecular simulations were carried out to study temperature effects (in the range of 323 to 383 K) on the absolute and relative retention of n-hexane, n-heptane, n-octane, benzene, toluene and the three xylene isomers in gas-liquid chromatography. Helium and squalane were used as the carrier gas and retentive phase, respectively. Both the experiments and the simulations show a markedly different temperature dependence of the retention for the n-alkanes compared to the arenes. For example, over the 60 K temperature range studied, the Kovats retention index of benzene is found to increase by about 16 or 18+/-10 retention index units determined from the experiments or simulations, respectively. For toluene and the xylenes, the experimentally measured increases are similar in magnitude and range from 14 to 17 retention index units for m-xylene to o-xylene. The molecular simulation data provide an independent method of obtaining the transfer enthalpies and entropies. The change in retention indices is shown to be the result of the larger entropic penalty and the larger heat capacity for the transfer of the alkane molecules.     

气相色谱-质谱法同时测定水果中9种保鲜剂的残留量

建立了采用气相色谱-质谱(GC-MS)同时测定水果中9种保鲜剂残留量的分析方法。水果样品用正己烷/乙酸乙酯(1/1,v/v)混合提取剂超声提取,经Florisil层析柱净化后用正己烷/乙酸乙酯(1/3,v/v)混合洗脱剂洗脱,以磷酸三苯脂(TPP)为内标物,采用GC-MS的全扫描方式(SCAN)和选择离子监测方式(SIM)对9种保鲜剂进行定性与定量分析。实验结果表明,9种保鲜剂的检出限(LOD)为0.10~2.16μg/kg,在50、100、200μg/kg添加水平下的回收率为75.3%~128%,相对标准偏差为1.57%~11.6%。本分析方法样品前处理简便,净化效果明显,在SIM谱图中分析目标物响应值大、灵敏度高,定量准确可靠,能够满足保鲜剂痕量残留的检测要求。     

The extraction and analysis of 1,4-dioxane from water using solid-phase microextraction coupled with gas chromatography and gas chromatography-mass spectrometry

In this study, two methods are developed for the extraction of 1,4-dioxane (dioxane) from water using 80-microm carboxen-polydimethylsiloxane solid-phase microextraction fibers followed by either gas chromatography (GC)-flame ionization detection (FID) or GC-mass spectrometry (MS). With GC-FID, the lower limit of detection (LOD) for 1,4-dioxane is 2.5 microg/L (ppb) with a linear range of 5 to 10,000 microg/L, obtained by immersing the fiber in the sample for 20 min with agitation. Using GC-MS, the lower limit of quantitation is 0.5 microg/L, and the LOD is 0.25 microg/L. The upper linear range limit is 100 microg/L. Samples are extracted in 20 min using either heated headspace with agitation or direct immersion with agitation.     

固相萃取-衍生化-气相色谱-质谱联用法同时测定尿液中4种阿片类物质

公安机关用胶体金尿检法对海洛因滥用者的检测常常受到阿片类镇咳药的干扰,使用传统液-液提取法进行实验室检验,操作效率低,灵敏度不高,无法满足公安机关打击涉毒案件的需要。为此,该研究建立了尿液中吗啡、O⁶-单乙酰吗啡、可待因和乙酰可待因4种阿片类物质的固相萃取和衍生化技术结合气相色谱-质谱联用(GC-MS)同时检测方法。尿样用磷酸盐缓冲液调节至pH=6后,经MCX固相萃取柱净化,用N-甲基-N-(三甲基硅烷基)三氟乙酰胺(MSTFA)对吗啡、O⁶-单乙酰吗啡、可待因进行衍生化,供GC-MS检测。考察了上样和洗脱流速、淋洗液中甲酸体积分数、洗脱液中氨水体积分数、3%(v/v)甲酸甲醇淋洗液体积和固相萃取柱吹干时间对萃取效果的影响。确定上样和洗脱流速1.0 mL/min,淋洗液中甲酸体积分数3%,洗脱液中氨水体积分数5%, 3%(v/v)甲酸甲醇淋洗液体积1 mL,吹干时间1 min为最佳条件。在此条件下,4种阿片类物质在0.02～0.8μg/mL范围内线性关系良好(r²≥0.998),检出限(LOD)为0.001 6～0.00...     

Determination of chloro-s-triazines including didealkylatrazine using solid-phase extraction coupled with gas chromatography-mass spectrometry

Chloro-s-triazines are a class of compounds comprising atrazine, simazine, propazine, cyanazine and their chlorinated metabolites. The US Environmental Protection Agency (EPA) has determined that selected chloro-s-triazines--atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine, and didealkylatrazine--have a common mode of toxicity related to endocrine disruption. In this paper, a dual-resin solid-phase extraction (SPE) gas chromatography-mass spectrometry (GC-MS) method is reported that provides for each of these chloro-s-triazines including the polar metabolite, didealkylatrazine. The method utilizes deuterated internal standards for quantitation and terbuthylazine as a recovery standard. The limit-of-detection was 0.01 microg/L for simazine, deethylatrazine, deisopropylatrazine and didealkylatrazine, and 0.02 microg/L for atrazine and propazine in surface water. Mean recoveries for 0.5 and 3.0 microg/L spikes for atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine and didealkylatrazine were 94, 104, 103, 110, 108 and 102%, respectively, in surface water. The method was also validated by matrix spikes into fourteen different raw and treated natural surface waters. This method is useful for monitoring "total chloro-s-triazines" in both raw and treated drinking waters.     

气相色谱-质谱法同时测定化妆品中19种邻苯二甲酸酯

建立了同时测定化妆品中19种邻苯二甲酸酯的气相色谱-质谱(GC-MS)方法。样品经二氯甲烷超声提取后,用硅胶-中性氧化铝(2:3, m/m)混合填料固相小柱保留、乙酸乙酯-正己烷(8:2, v/v)洗脱等步骤净化后,采用GC-MS对19种目标物进行定性、定量分析。采用保留时间与特征离子丰度比共同进行定性分析,减少了复杂样品基质中的干扰。在优化的实验条件及0.1、0.5、2.0 μg/g的添加水平下,平均加标回收率为72.2%～110.9%,其中加标水平为0.1 μg/g的相对标准偏差(RSD, n=6)小于10.3%;方法检出限(以3倍标准偏差计)为0.0065 μg/g(邻苯二甲酸二异戊酯)～0.062 μg/g(邻苯二甲酸二异丁酯)之间。应用该方法检测了6种化妆品中19种PAEs的含量。该方法可推广用于多种类型化妆品中PAEs的测定。     

热脱附-气相色谱-质谱法测定环境空气中67种挥发性有机物

采用热脱附-气相色谱-质谱法,建立了同时分析环境空气中67种挥发性有机物的分析方法。对比了5种不同填充材料不锈钢吸附管对78种挥发性有机物的吸附能力。填充材料为Tenax TA和Carbograph 1TD的混合填料吸附管对分析物的捕集效果最好,在30 mL/min高纯He气持续吹脱45 min的情况下,未发生穿透（即穿透率小于10%）的化合物达67种,分析物的种类包括芳香烃、脂肪烃、卤代烃和含氧挥发性有机物等。优化了使用该吸附管测定67种目标物时的热脱附条件。在5~100 ng范围内,目标化合物的色谱响应值与其量间具有良好的线性关系,其相关系数（r）均在1.0000~0.9977之间。方法检出限为0.3~2.4 ng,以采样体积1 L计算,检出限为0.3~2.4 μg/m³。加标量为20 ng时,7次重复实验目标化合物回收率均在81.6%~114.9%之间,目标化合物的相对标准偏差为1.2%~10.1%。采用该方法对某车厢内空气进行了检测,检出了包括酯类、卤代烷烃、卤代烯烃以及芳香族化合物在内的19种目标化合物,其范围为1.1~84.1 μg/m³。该方法准确、可靠、灵敏度高,实现了对环境空气中67种目标污染物的准确定量。     

Impurity analysis of 1,4-dioxane in nonionic surfactants and cosmetics using headspace solid-phase microextraction coupled with gas chromatography and gas chromatography-mass spectrometry

1,4-Dioxane impurity in nonionic surfactants and cosmetics were analyzed using solid-phase microextraction (SPME) coupled with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Experimental results show that there is no significant difference using SPME-GC and SPME-GC-MS for analysis of 1,4-dioxane in three types of nonionic surfactants at the 95% confidence level. The relative standard deviation (R.S.D.) values of each analytical method were smaller than 3%. The amount of 1,4-dioxane was found to vary from 11.6 +/- 0.3 ppm to 73.5 +/- 0.5 ppm in 30% of nonionic surfactants from manufacturers in Taiwan. These methods were linear over the studied range of 3-150 ppm with correlation coefficients higher than 0.995. The recoveries of 1,4-dioxane for these nonionic surfactants following SPME were all higher than 96 +/- 1% (n = 3). The detection limits of 1,4-dioxane for these nonionic surfactants following SPME were from 0.06 ppm to 0.51 ppm. The experimentally determined level of 1,4-dioxane in cosmetics from manufacturers in Taiwan varied from 4.2 +/- 0.1 ppm to 41.1 +/- 0.6 ppm in 22% of daily used cosmetics following SPME coupled with GC and GC-MS. Conventional solvent extraction takes around 1 h for extraction and reconcentration but SPME takes only around 10 min. SPME provides better analyses of 1,4-dioxane in nonionic surfactants and cosmetics than conventional solvent extraction and head space pretreatments in term of simplicity, speed, precision, detection limit, and solvent consumption.     

自制炭阱吸附装置与气相色谱-质谱联用测定植物的挥发性有机物

设计组装了炭阱吸附装置,并与气相色谱-质谱(GC-MS)联用测定了银杏叶和利马豆的挥发性有机物。采用炭阱吸附装置与固相微萃取(SPME)收集银杏叶的挥发性有机物,用GC-MS进行分析,结果表明采用炭阱吸附装置对银杏叶挥发性有机物的富集效果优于SPME方法。实验还采用内标法对利马豆的挥发性有机物进行了初步的定量,两次实验结果的重复性较好。由于炭阱吸附装置能够很好地收集植物的挥发性有机物,且可以进行多个样品的平行实验及植物挥发性有机物的定量研究,因此炭阱吸附装置与GC-MS联用更适合用于实验室中植物挥发性有机物的研究。     

Multicapillary gas chromatography coupled to inductively coupled plasma-time-of-flight mass spectrometry for rapid mercury speciation analysis

A simple, rapid and accurate method on the basis of multicapillary gas chromatography (MCGC) combined with inductively coupled plasma-time-of-flight mass spectrometry (ICP-TOFMS) was developed for speciation analysis of methylmercury (MeHg⁺) and inorganic mercury (Hg²⁺). The potential of the ICP-TOFMS for transient multi-isotope detection of very short signals (peak width of 0.4 s at half peak height) was evaluated. Two injection systems (purge-and-trap (PTI) and split (SI) injections) were compared in terms of species separation resolution and transient signal profile. Using purge-and-trap injection, after in situ derivatization of the ionic mercury species with sodium tetraethylborate, a baseline separation of MeHg⁺ and Hg²⁺ was achieved within a chromatographic run of <35 s. To correct for matrix-induced ion signal variation and instrumental drift, propylmercury (PrHg⁺) was used as internal standard. Detection limits of 16 and 257 fg g⁻¹ for MeHg⁺ (as Hg) and Hg²⁺, respectively, were achieved. The analytical precision (R.S.D. (%)) for 10 successive injections of a standard mixture containing 10 pg MeHg⁺ (as Hg) and Hg²⁺ was 1.2% for MeHg⁺ and 4.1% for Hg²⁺. The method was validated by analysis of two biological certified reference materials (CRM): a dogfish muscle (DORM-2) and a freeze-dried tuna fish (CRM 464).     

Simultaneous determination of eight common odors in natural water body using automatic purge and trap coupled to gas chromatography with mass spectrometry

Production and fate of taste and odor (T&O) compounds in natural waters are a pressing environmental issue. Simultaneous determination of these complex compounds (covering a wide range of boiling points) has been difficult. A simple and sensitive method for the determination of eight malodors products of cyanobacterial blooms was developed using automatic purge and trap (P&T) coupled with gas chromatography-mass spectrometry (GC-MS). This extraction and concentration technique is solvent-free. Dimethylsulfide (DMS), dimethyltrisulfide (DMTS), 2-isopropyl-3-methoxypyrazine (IPMP), 2-isobutyl-3-methoxypyrazine (IBMP), 2-methylisoborneol (MIB), β-cyclocitral, geosmin (GSM) and β-ionone were separated within 15.3 min. P&T uses trap #07 and high-purity nitrogen purge gas. The calibration curves of the eight odors show good linearity in the range of 1-500 ng/L with a correlation coefficient above 0.999 (levels=8) and with residuals ranging from approximately 83% to 124%. The limits of detection (LOD) (S/N=3) are all below 1.5 ng/L that of GSM is even lower at 0.08 ng/L. The relative standard deviations (RSD) are between 3.38% and 8.59% (n=5) and recoveries of the analytes from water samples of a eutrophic lake are between 80.54% and 114.91%. This method could be widely employed for monitoring these eight odors in natural waters.     

气相色谱-质谱法同时测定透皮接收液中的丙胺卡因和利多卡因

建立了同时测定体外透皮接收液中丙胺卡因和利多卡因的气相色谱-质谱(GC-MS)分析方法。以罗哌卡因为内标,样品经氢氧化钠碱化、乙酸乙酯萃取后采用GC-MS分析,采用选择离子监测(SIM)模式进行定量分析。丙胺卡因和利多卡因两种药物均在0.016～50.0 mg/L范围内呈良好的线性关系;回收率为85.3%～109.7%,日内和日间测定的相对标准偏差均小于10%;检出限分别为3 μg/L和2 μg/L。该方法操作简便,选择性好,灵敏度高,适用于局部麻醉药物快速透皮吸收研究中丙胺卡因和利多卡因含量的分析。     

气相色谱-质谱法测定人血清中多溴联苯

建立了血清中8种多溴联苯(PBBs,包括BB-15、18、52、101、153、180、194和206)的气相色谱-质谱检测方法。采用Oasis HLB固相萃取柱对血清样品中的多溴联苯进行萃取和初步净化,再使用自制的硅胶/酸化硅胶固相萃取柱(Sep-Pak silica/acidified silica)进行进一步的净化,并以正己烷为洗脱溶剂洗脱,氮吹洗脱液浓缩至100 μL后上样分析。以DB-5ms色谱柱(15 m×0.25 mm×0.1 μm)分离样品,在选择离子监测(SIM)模式下进行质谱检测,使用同位素内标法对8种目标物进行准确定量。结果显示,8种多溴联苯单体的方法检出限(LOD,以3.14倍标准偏差计)为0.002～0.029 ng/mL,方法定量限(LOQ,以10倍标准偏差计)为0.008～0.092 ng/mL;低、中、高3个加标水平的平均回收率为74.24%～119.49%,相对标准偏差(RSD)为1.23%～12.02%。采用本方法测定标准参考物质SRM1957和SRM1958中的BB-153含量,结果在参考值范围内。本方法准确、灵敏、操作简便,适用于血清中多溴联苯的测定。     

Solid-phase microextraction coupled with gas chromatography-ion trap mass spectrometry for the analysis of haloacetic acids in water

Headspace solid-phase microextraction (SPME) was studied as a possible alternative to liquid-liquid extraction for the analysis of haloacetic acids (HAAs) in water. The method involves derivatization of the acids to their ethyl esters using sulphuric acid and ethanol after evaporation, followed by headspace SPME with a polydimethylsiloxane fibre and gas chromatography-ion trap mass spectrometry (GC-IT-MS). The derivatization procedure was optimized: maximum sensitivity was obtained with esterification for 10 min at 50 degrees C in 30 microl of sulphuric acid and 40 microl of ethanol. The headspace SPME conditions were also optimized and good sensitivity was obtained at a sampling temperature of 25 degrees C, an absorption time of 10 min, the addition of 0.1 g of anhydrous sodium sulfate and a desorption time of 2 min. Good precision (RSD lower than 10%) and detection limits in the ng l(-1) range (from 10 to 200 ng l(-1)) were obtained for all the compounds. The optimized procedure was applied to the analysis of HAAs in tap water and the results obtained by standard addition agreed with those of EPA method 552.2, whereas discrepancies due to matrix interferences were observed using external calibration. Consequently, headspace SPME-GC-IT-MS with standard addition is recommended for the analysis of these compounds in drinking water.     

Simultaneous analysis of pesticides from different chemical classes by using a derivatisation step and gas chromatography-mass spectrometry

This work presents a new method to analyse simultaneously by GC–MS 31 pesticides from different chemical classes (2,4 D, 2,4 MCPA, alphacypermethrin, bifenthrin, bromoxynil, buprofezin, carbaryl, carbofuran, clopyralid, cyprodinil, deltamethrin dicamba, dichlobenil, dichlorprop, diflufenican, diuron, fenoxaprop, flazasulfuron, fluroxypyr, ioxynil, isoxaben, mecoprop-P, myclobutanil, oryzalin, oxadiazon, picloram, tau-fluvalinate tebuconazole, triclopyr, trifluralin and trinexapac-p-ethyl). This GC–MS method will be applied to the analysis of passive samplers (Tenax^® tubes and SPME fiber) used for the evaluation of the indoor and outdoor atmospheric contamination by non-agricultural pesticides. The method involves a derivatisation step for thermo-labile or polar pesticides. Different agents were tested and MtBSTFA (N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide), a sylilation agent producing very specific fragments [M−57], was retained. However, diuron could not be derivatised and the isocyanate product was used for identification and quantification. Pesticides which did not need a derivatisation step were not affected by the presence of the derivatisation agent and they could easily be analysed in mixture with derivatised pesticides. The method can be coupled to a thermal-desorption unit or to SPME extraction for a multiresidue analysis of various pesticides in atmospheric samples.     

Optimization and validation of a method of analysis for fenitrothion and its main metabolites in forestry air samples using sorbent tubes with thermal desorption cold trap injection and gas chromatography-mass spectrometry

An analytical methodology using thermal-desorption cold trap (TCT) and GC-MS was developed for the determination of the insecticide fenitrothion and its main metabolites, 3-methyl-4-nitrophenol and fenitrooxon, in forestry atmospheres. The sampled atmosphere was pumped through a glass tube containing 100 mg of Tenax adsorbent at a flow rate of 50 ml min(-1). Adsorption/thermal desorption and breakthrough experiments were performed to test the ability to quantitatively trap the compounds. The detection limits of method for these compounds ranged between 1.6 and 2.1 ng m(-3). This methodology was developed to evaluate the persistence of fenitrothion in forest atmospheres after treatment. Spray application at 21.5 mg active ingredient m(-2) resulted in atmosphere levels of the insecticide of 78.3 ng m(-3) (after 2 h of application). Within 2-4 days following treatment, the presence of fenitrooxon fell to 50-55%. During this period residues of metabolites began to appear, disappearing 19 days later.     

Simultaneous determination of aliphatic and aromatic amines in indoor and outdoor air samples by gas chromatography-mass spectrometry

A gas chromatography-mass spectrometry (GC-MS) method has been proposed for the simultaneous determination of aliphatic and aromatic amines in indoor and outdoor air samples. The method includes pre-concentration of the compounds by percolating the air samples through the acidic solution, ion-pair extraction with bis-2-ethylhexylphosphate (BEHPA), derivatisation of compounds with isobutyl chloroformate (IBCF) and their GC-MS analysis. Aliphatic and aromatic amines were isolated from aqueous samples using BEHPA as ion-pair reagent and derivatised with IBCF for their chromatographic analysis. Aliphatic and aromatic amines were then analysed with GC-MS in both electron impact (EI) and positive and negative ion chemical ionisation (PNICI) mode as their isobutyloxycarbonyl (isoBOC) derivatives. The obtained recoveries ranged from 75.6 to 96.8% and the precision of this method, as indicated by the relative standard deviations (R.S.D.) was within the range of 1.0-4.4%. The detection limits obtained from calculations by using GC-MS results based on S/N: 3 were within the range of 0.08-0.01 ng/m³.     

Modified sampling and analysis method for large volatility range airborne polycyclic aromatic hydrocarbons (PAH) using gas chromatography-mass spectrometry

A sampling method has been developed for the measurement for polycyclic aromatic hydrocarbons in ambient air by gas chromatography isotope dilution mass spectrometry. The method has been designed to measure the largest possible volatility range of PAHs including the abundant naphthalenes. Sample volumes were approx. 500 m³ in size at a sampling rate of approx. 18 m³/h. The sampler contained three sorption stages for the simultaneous capturing of particle bound and low and high volatile gaseous PAH, respectivley. Recoveries of sampling spikes were on average 90%. The detection limit was approx. 5 pg/m³ for the high boiling range PAH. Results obtained showed a quite steady profile for most PAH in background air in The Netherlands. Comparison of abundance ratios with literature data indicate that traffic exhausts are the major source for the PAH in the area.