针式萃取-气相色谱联用测定加油站附近空气中苯系物

提出了气相色谱法测定加油站附近空气中苯系物(甲苯、乙苯、邻二甲苯和间,对二甲苯)含量的方法。采用针式萃取装置对样品中的苯系物进行收集和富集,然后经气相色谱热解吸,采用SE 30毛细管色谱柱(30m×0.25mm,0.33μm)进行分离,用氢火焰离子化检测器进行测定。方法的检出限(3S/N)在0.36～1.32μg之间。方法的回收率在94.1%～104.5%之间,相对标准偏差(n=5)在4.9%～8.7%之间。     

气相色谱法测定密闭空间空气中7种苯系物

建立气相色谱法测定密闭空间空气中异丙苯等7种苯系物的方法。采用活性炭富集采样,二硫化碳解吸样品,DB-624毛细管柱分离,实现了对异丙苯、正丙苯、特丁苯、正丁苯、仲丁基苯、1,3,5-三甲苯、1,2,4-三甲苯等7种苯系物完全分离并准确测定,特别是可以将难分离的1,3,5-三甲苯和仲丁基苯完全分离。建立的7种苯系物工作曲线线性良好,相关系数r^2≥0.997,加标回收率在83.2%~111.0%之间,测定结果的相对标准偏差不大于6.3%(n=6),方法检出限为0.02~0.06 mg/m^3。该方法选择性好,测量范围宽,方法检出限低,可用于密闭空间空气中异丙苯等7种苯系物的测定。     

近红外光谱法快速测定溶剂型木器涂料中甲苯、乙苯和二甲苯

建立了使用近红外光谱法(NIR)快速测定溶剂型木器涂料中甲苯、乙苯和二甲苯的方法。收集涂料样品,使用气相色谱法(GC)测定苯系物含量。采用聚乙烯密实袋封装聚氨酯类、硝基类或醇酸类涂料,应用积分球透漫射采样方式采集清漆和漫射采样方式采集色漆的近红外光谱。采用偏最小二乘法,分别建立清漆和色漆的近红外光谱与苯系物线性关系模型。校正集均方差在0.43%~1.32%之间、相关系数R在0.9046~0.9766之间。验证集均方差在0.591%~1.73%之间。对未知样品预测,清漆样品预测值相对偏差<15%;色漆样品预测值相对偏差<20%。两个定量模型预测效果良好。该2个NIR定量方法适用于对溶剂型木器涂料中甲苯、乙苯和二甲苯含量进行快速测定。     

正己烷萃取-顶空气相色谱法测定乳胶漆中苯系物含量

应用顶空气相色谱法测定了乳胶漆中7种苯系物,即苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯及苯乙烯.作为对常规的顶空法的改进,乳胶漆中的上述7种化合物预先在顶空瓶中用n-已烷萃取,以提高方法的回收率.取1 mL气体供气相色谱分析,用HP-INNOWAX极性柱作为分离柱,并采用氢火焰离子化检测器.按保留时间值作定性分析,定量分析则采用外标法.文中给出7种化合物的线性回归方程,其相关系数在0.9989～0.9999之间,求得7种化合物的检出限(S/N=3)为0.05 ng或0.1 μg·kg-1(对0.5g试样).用此方法分析了两件乳胶漆样品,根据测得结果,算得其相对标准(n=5)值均小于5%;进行了回收试验,回收率结果苯为90%～105%,甲苯为88%～102%,乙苯为85%～102%,二甲苯为80%～98%及苯乙烯为85%～102%.     

气相色谱法同时测定涂料中的苯系物和邻苯二甲酸酯类环境激素

建立了涂料中苯、甲苯、二甲苯异构体、邻苯二甲酸酯类化合物(DEP、DBP、BBP、DEHP、DNOP)多种有毒有害成分同时检测技术 ;用化学和吸附/脱附惰性膜除去样品中的大部分树脂成膜物质、颜填料及各种微粒助剂 ;用毛细管柱气相色谱分离 ,内标法定量 ;苯系物的线性范围为1×10-2～100μg,邻苯二甲酸酯类增韧剂为5×10-2～20μg;苯系物的回收率为97 %～103 % ,相对标准偏差 (RSD)的范围为0.12 %～0.95 % ;邻苯二甲酸酯类增韧剂的回收率为96 %～102 % ,相对标准偏差 (RSD)的范围为0.92 %～2.46 %。结果表明 :该方法简便、快速、灵敏、精密度好。     

气相色谱-质谱法测定修正产品中11种苯系物

建立了气相色谱-质谱法同时测定修正产品中11种苯系物(苯,甲苯,乙苯,对-二甲苯,间-二甲苯,邻-二甲苯,苯乙烯,氯苯,1,3-二氯苯,1,4-二氯苯,1,2-二氯苯)含量的检测技术。试样中苯系物经二甲亚砜萃取,经DBWAX型毛细管色谱柱分离,质谱定量。结果表明:11种苯系物在1.0~20.0 mg/kg范围内呈良好的线性关系,相关系数R20.9996;方法检出限在0.04~0.07 mg/kg之间;回收率为89.1%~101.1%,相对标准偏差(RSD)1.5%~4.4%。方法能够满足对修正产品中11种苯系物的分析要求。     

多束毛细管柱–离子迁移率谱检测环境大气中的苯系物

采用多束毛细管柱–离子迁移率谱(MCC–IMS)系统对环境大气中的苯、甲苯、乙苯、二甲苯和苯乙烯5种苯系物进行快速检测。IMS漂移管温度为80℃,载气和漂移气均为洁净空气,测得苯系物的约化迁移率。苯、甲苯、乙苯、二甲苯和苯乙烯分别在0.20~3.00,0.20~2.00,0.15~1.00,0.25~3.00,0.08~1.00 mg/m~3质量浓度范围内线性良好,线性相关系数均不小于0.96。基于3倍噪声计算,苯、甲苯、乙苯、二甲苯和苯乙烯的检出限分别为0.055,0.023,0.017,0.065和0.013 mg/m~3。MCC–IMS法可快速检测混合样品中5种苯系物,其中苯、甲苯和苯乙烯的定量相对误差分别为5.0%,9.4%,0.2%,测定结果的相对标准偏差分别为2.7%,5.0%,6.7%(n=6)。MCC–IMS的单次测量可在3 min内完成。     

顶空气相色谱法同时测定树脂工艺品中7种残留苯系物

建立了顶空气相色谱(HS-GC)同时测定树脂工艺品中7种残留苯系物BTEX(苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯)的方法。对溶剂种类、萃取温度、萃取时间及HG-GC分离测定条件进行优化。结果表明,在顶空温度为130℃、平衡时间为60 min、粉碎样品粒径低于2 mm、选择DB-WAX色谱柱的条件下,可获得良好的分离效果和定量结果。7种残留苯系物在0.1～500μg范围内具有良好的线性关系(r2>0.999)。方法的定量下限(LOQ,S/N=10)在0.1～0.4μg.g-1之间,加标回收率为93%～114%,相对标准偏差(RSDs,n=6)为0.7%～4.8%。所建立的方法快速、准确,适用于树脂工艺品中苯系物的测定。     

顶空-气相色谱法测定海水中8种苯系物

提出了顶空-气相色谱法测定海水中残留的8种苯系物的方法。分别选择40℃及30min作为样品在顶空瓶中的平衡温度和平衡时间。选用Nukol毛细管色谱柱(30m×0.25mm,0.25μm)分离,氢火焰离子化检测器测定。8种苯系物在13min内能完全分离。8种苯系物的质量浓度在10.0～200μg.L-1范围内与其峰面积呈线性关系,检出限(3S/N)均为2μg.L-1。以海水样品为基体,在3个浓度水平上进行加标回收试验,回收率在93%～119%之间,相对标准偏差(n=6)在1.1%～5.3%之间。     

顶空单液滴微萃取-气相色谱法测定水中苯系物

采用顶空单液滴微萃取样品处理方法分离富集水中苯系物,用气相色谱法进行测定.考察了不同萃取剂、萃取条件对检测结果的影响.苯、甲苯、对二甲苯的检出限分别为0.05,0.05,0.03 μg·L-1,三种苯同系物的相关系数分别为0.999 2,0.998 5和0.997 2,回收率分别为98.3%,101.9%和97.3%.     

用胶束电动毛细管色谱法测定海洋沉积物中苯系物

海洋沉积物中苯系物的分析和测量对海洋石油化探具有重要意义。作者用胶束电动毛细管色谱法对海洋沉积物中苯系物进行了测定。考察了十二烷基硫酸钠 (SDS)的浓度和有机添加剂对分离的影响以及影响峰面积重现性和迁移时间的因素。苯系物的浓度和对应的峰面积成良好的线性关系。将该法用来分析石油勘探远景区域海洋沉积物中的苯系物 ,得到了它们的含量范围。     

Quantitative analysis of trace‐level benzene,toluene, ethylbenzene,and xylene in cellulose acetate tow using headspace heart‐cutting multidimensional gas chromatography with mass spectrometry

This study describes a method for the quantification of trace‐level benzene, toluene, ethylbenzene, and xylene in cellulose acetate tow by heart‐cutting multidimensional gas chromatography with mass spectrometry in selected ion monitoring mode. As the major volatile component in cellulose acetate tow samples, acetone would be overloaded when attempting to perform a high‐resolution separation to analyze trace benzene, toluene, ethylbenzene, and xylene. With heart‐cutting technology, a larger volume injection was achieved and acetone was easily cut off by employing a capillary column with inner diameter of 0.32 mm in the primary gas chromatography. Only benzene, toluene, ethylbenzene, and xylene were directed to the secondary column to result in an effective separation. The matrix interference was minimized and the peak shapes were greatly improved. Finally, quantitative analysis of benzene, toluene, ethylbenzene, and xylene was performed using an isotopically labeled internal standard. The headspace multidimensional gas chromatography mass spectrometry system was proved to be a powerful tool for analyzing trace volatile organic compounds in complex samples.     

顶空直接进样气相色谱法测定黏胶剂中的苯系物

目的建立检测黏胶剂中苯系物的方法。方法用顶空直接进样气相色谱法测定黏胶剂中的苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯以及苯乙烯7种组分,对气相色谱柱、顶空加热温度以及顶空提取时间进行了讨论。结果对苯乙烯等7种被测组分的检测限均小于5mg/kg,7种组分在毛细管柱中能够很好的分离,回收率范围为81%～94%,RSD为5%～10%,具有操作简单、快速等特点。结论能够满足对黏胶剂中苯系物测定的分析要求。     

High benzene selectivity of mesoporous silicate for BTX gas sensing microfluidic devices

The gas selectivities of highly ordered mesoporous silicates and commercially-obtained porous silicates with respect to benzene, toluene and xylene were studied. After studying the porosities, pore uniformities, and surface silanol structures of the silicates and their relationships to gas selectivity in detail, we found that we could achieve high benzene selectivity by controlling the micropore size (less than 1 nm). Concluding that mesoporous silicate has a suitable micropore size and structure for benzene selectivity, we also observed that mesoporous silicate SBA-16 exhibited a high (>6) benzene selectivity from toluene and xylene even in a pseudo-atmospheric environment. A benzene detection limit of about 100 ppb was achieved by introducing SBA-16 into a microfluidic device originally developed for the separate detection of benzene, toluene, and xylene gases.     

苯酚、马尿酸和甲基马尿酸的反相高效液相色谱分析

本文提出了人体内苯、甲苯和二甲苯的代谢产物苯酚、马尿酸和甲基马尿酸的反相高效液相色谱分析法,讨论了其保留机制和样品预处理技术.以ODS为固定相,甲醇-水-醋酸为流动相时可实现良好分离.方法回收率为97.3%,相对标准偏差为1.02%.提出的方法可用于尿样分析,适用于临床与职业病防治的监测分析.     

胶束电动毛细管色谱法测定海洋沉积物中的苯、甲苯和二甲苯

 建立了用胶束电动毛细管色谱法（MECC）对海洋沉积物中的苯、甲苯和二甲苯进行 分析测定的方法 。用45 cm（到检测窗口40 cm）×75　μm i.d.毛细管柱,以75　mmol/L SDS-2　mmol/L 四硼酸钠溶液（外加体积分数为20%的甲醇）为缓冲液（pH 9.16）。当电压为25 kV、检测 波长为200 nm时,苯、甲苯和二甲苯在20 min内得到了良好的分离。用峰面积定量,线性范 围为4～50 mg/L,相对标准偏差在6.2%以内。测得海洋沉积物中的这些苯系物的质量比范围 为3.79～17.36 μg/g。     

Trace analysis of benzene,toluene, ethylbenzene and xylene isomers in environmental samples by low-pressure gas chromatography-ion trap mass spectrometry

A rapid determination of benzene, toluene, ethylbenzene and the three xylene isomers (BTEX), including a nearly baseline separation of the xylene isomers in environmental samples within 1 min has been carried out using low-pressure gas chromatography-ion trap mass spectrometry (LP-GC-IT-MS). In order to evaluate the different parameters which may influence the performance of LP-GC-IT-MS, different column and mass spectral parameters were varied. Comparing LP-GC-IT-MS with the conventional equivalent, we obtained excellent detection limits as well as a good RSD of 8-13% in ition to a much shorter analysis time. In order to evaluate LP-GC-IT-MS for use in environmental samples, we determined BTEX in air.     

Study on adsorption kinetic of aromatic hydrocarbons onto activated carbon in gaseous flow method

The adsorption behavior of benzene, toluene, o-xylene, m-xylene, and p-xylene onto activated carbon was investigated using the flow method. The removal efficiency of aromatic hydrocarbons in the gaseous phase was estimated based on the adsorption kinetic constants and the saturated amount of aromatic hydrocarbons adsorbed on the activated carbon. The saturated amount of benzene and toluene adsorbed was greater than that of xylene adsorbed because the molecular sizes of benzene and toluene are smaller than that of xylene. The adsorption kinetic constant increased in the order of xylene, toluene, and benzene. Those of the three xylene isomers were similar. These results indicated that the adsorption rate of benzene by the activated carbon was the fastest and the kinetic constant depended upon the different between the boiling point and the melting point and the molecular size of the aromatic hydrocarbons.     

Cryogenic oven-trapping gas chromatography for analysis of volatile organic compounds in body fluids

Cryogenic oven-trapping (COT) with capillary GC has been successfully applied to analysis of chloroform, dichloromethane, trichloroethylene, diethyl ether, the components of solvent thinner (ethyl acetate, benzene, n-butanol, toluene, and others), xylene isomers, cyanide, ethanol, hexanes, general anesthetics, and styrene in human body fluids. This COT-GC technique was compared with headspace solid-phase microextraction (SPME) coupled with GC for some volatile organic compounds (VOC); for all compounds compared the sensitivity achieved using COT-GC was more than ten times higher than for headspace SPME-GC. The COT-GC method is recommended for widespread use in forensic and environmental toxicology, because it is simple, requires no special GC operations, and yet enables high sensitivity and high resolution.     

Rapid hydrocarbon analysis using a miniature rectilinear ion trap mass spectrometer

A miniature ion trap mass analyzer was applied to the analysis of traces of hydrocarbons and simple heteroatomics in the vapor phase and in aqueous solution. Vapors of acetone, acetic acid, acetonitrile, benzene, butanethiol, carbon disulfide, hexane, dichloromethane, naphthalene, toluene and xylenes were detected and quantified using solid sorbent trapping and, in some cases, by passage through a membrane interface. Aqueous solutions of benzene, toluene, xylenes, hexane and a petroleum naphtha distillate were examined using the membrane interface. Sampling, detection and identification of all compounds was completed in times of less than one minute. The gas-phase samples of toluene and benzene were detected at 200 ppt (limit of detection, LOD) for toluene and 600 ppt for benzene. Identification of benzene and xylene in aqueous solutions was readily achieved with LODs of 200 and 400 ppb, respectively. Quantification over a linear dynamic range of two orders of magnitude for the aqueous samples and three orders of magnitude for the vapor-phase samples was demonstrated.