顶空-气相色谱法测定纸类印刷品中16种挥发性有机物

提出了顶空-气相色谱法测定纸类印刷品中16种挥发性有机物(VOCs)的方法。选用三醋酸甘油酯为溶剂,对平衡时间及平衡温度进行优化。结果表明,本方法测定16种挥发性有机物的线性范围为0～100mg/m2,最低定量限为(10S/N)为0.005mg/m2,回收率为94.79%～101.77%,样品6次重复测定的峰面积的相对标准偏差小于5%。     

工业废水中有机类化合物含量测定

针对工业废水中部分有机类化合物易挥发、难测定的问题,研究提出顶空和气相色谱-质谱法,测定了工业废水中的55种挥发性有机物含量。研究氟苯和1,2-二氯苯-D4为内标物,在顶空平衡温度为65℃、平衡时间为50min时,分别采用全扫描和离子扫描对工业废水中有机类化合物含量进行测定,得到废水中10种挥发性有机物的线性范围在10～300μg/L。当采用全扫描时,其检出限范围0.8～6.8μg/L,加标回收率在81%～116%,相对标准偏差在0.38%～15.25%;当采用离子扫描时,检出限在0.2～1.1μg/L,加标回收率在81%～118%,相对标准偏差在0.38%～7%。     

顶空-GC/MS测定土壤中挥发性有机物的探究

采用静态顶空-气相色谱/质谱法对土壤中31种挥发性有机物进行分析测定,主要对检测方法的过程与结果进行探究。结果表明:土壤中31种挥发性有机物的检出限为0.01～0.29μg/kg,回收率为98.2%～104.03%,校准曲线线性相关性均在0.995以上,满足土壤中挥发性有机物的测定标准。     

顶空-气相色谱法测定烟用胶粘剂中的挥发性有机物

采用顶空-气相色谱法对烟用胶粘剂中的挥发性有机物(甲醇、丙酮、乙酸甲酯、叔丁醇、乙酸乙烯酯、乙酸乙酯)进行分析,讨论了气相色谱柱的升温方式、顶空平衡温度、平衡时间、胶粘剂加入量对分析结果的影响,从而获得优化的检测工艺参数。该检测方法对上述6种挥发性有机物的线性范围分别为甲醇40～400μg/g,丙酮4～40μg/g,乙酸甲酯9.2～92μg/g,叔丁醇3.2～32μg/g,乙酸乙烯酯7.5～75μg/g,乙酸乙酯4.5～45μg/g,测定结果的相对标准偏差为0.6%～2.7%,样品的回收率为90.8%～104.2%。该方法可用于烟用胶粘剂中挥发性有机物的分析,方法简便、快速、重现性好。     

液体浸出一顶空进样一便携GC／MS法测定土壤中挥发性有机物

建立了液体浸出一顶空进样一便携气相色谱,质谱法测定土壤中的挥发性有机物（VOCs）的方法。结果表明,该方法简单、方便、准确,24种挥发性有机物的实际样品加标回收率可达60％以上。本方法采用便携气质进行定性和定量,可以应用于土壤污染事故应急监测的挥发性有机物现场检测。     

顶空-气相色谱同时测定饮用水中7种挥发性卤代烃类有机物

目的:建立一种顶空-气相色谱同时测定生活饮用水中7种挥发性卤代烃的方法。方法:该方法集平衡升温、自动进样、气相色谱分离于一体,在优化仪器的色谱条件的基础上对顶空进样平衡温度、平衡时间、气液体积比和氯化钠加入量进行研究。样品经HP-35色谱柱分离,电子捕获检测器检测,外标法定量,保留时间定性。结果:7种挥发性卤代烃相关系数r为0.9983～0.9997,加标回收率为81.3%～110.2%,相对标准偏差为2.0%～9.0%,检出限为0.10～0.59μg/L。结论:实际样品测定结果表明,本方法能有效分离水中7种挥发性卤代烃,适用于饮用水中卤代烃的准确分析测定。     

顶空-气相色谱串联质谱法测定修正液中六种苯系物

采用顶空-气相色谱串联质谱法测定修正液中六种苯系物,选用硅油作为基质,通过实验确认顶空平衡温度和平衡时间为:90℃和10 min,并进行了色谱条件的优化。该方法简单可靠,准确度高,线性范围为0.1~100 mg/kg,最低检测浓度为0.1 mg/kg,方法回收率为91.2%~96.4%,相对标准偏差为4.3%~7.9%。该方法可以准确定性、定量测定修正液中的6种苯系物。     

便携式气质联用仪测定土壤挥发性有机物

挥发性有机物进入土壤后造成污染,影响土壤环境质量。通常对土壤中挥发性有机物分析的标准主要是顶空和吹扫捕集与气相色谱质谱联用为常用的测定方法。本文使用便携式气相色谱质谱联用仪研究土壤11种挥发性有机物检测方法,获得11种挥发性有机物检出限在2.2～4.3μg/kg,实际样品平行样相对偏差为0～8.5%,样品加标回收率范围在60.8%～126.5%之间。研究结果表明:本方法测定土壤挥发性有机物的有效可行,能够为应急监测提供有效支撑。     

顶空-气相色谱-质谱法测定EVA地垫中甲酰胺含量

建立了顶空-气相色谱-质谱法测定乙烯-醋酸乙烯酯共聚物(EVA)地垫中甲酰胺含量的分析测试方法。将顶空平衡温度和时间分别选定为160℃和40 min,通过HP-INNOWax色谱柱(60 m×250μm×0.5μm)进行分离,采用选择离子监测模式检测,外标法定量。结果表明:甲酰胺在1~100μg范围内线性关系良好(R~20.999)。方法的检出限(S/N=3)为5 mg/kg,加标回收率为81.23%~96.91%。该方法操作简单、快速、灵敏度高,适用于EVA地垫中甲酰胺的快速检测。     

顶空气相色谱-质谱联用法测定蜡烛中香茅油的含量

本文采用顶空进样气相色谱-质谱联用法测定蜡烛中香茅油的含量。选用硅油为母液,优化了色谱条件、顶空加热温度、平衡时间等实验条件,并进行了线性、精密度和回收率实验。方法简单、快速,定性定量准确可靠。     

气相色谱法中顶空分析技术有关问题的探讨

介绍了气相色谱分析法中顶空技术的原理和特点,用实例对顶空法的适用性进行了探讨.顶空分析技术具有样品预处理简单、避免大量液相基体干扰、不易沾污或损坏色谱柱、检测灵敏度高等特点,尤其适用于具有高挥发性、高气液相分配比的物质;并且提高水相中的无机盐浓度,可以显著提高被测物质的响应值.但是对于非均相的乳液状态的样品,顶空分析技术不适用.该技术用于废水中痕量全氟异丁烯(PFIB)含量的测定,检测限达到0.04 mg/m3.     

山东北柴胡果实挥发性成分的气质联用分析

建立了顶空静态进样GC-MS快速分析北柴胡果实挥发性成分的方法。选择北柴胡果实,采用顶空静态提取的方法,提取物直接经气相色谱-质谱分析,以NIST数据库检索化合物的结构,以峰面积归一化法测定各挥发性成分的相对含量。结果表明:顶空加热提取挥发性成分经GC-MS分析,鉴定柴胡果实中36个挥发性化学成分,主要挥发性成分为1-甲基-5-亚甲基-8-(1-甲乙基)-1,6-环癸二烯(36.04%),3.7-二甲基-1,3,6-辛三烯(14.77%),2-乙基呋喃(4.42%)。顶空静态进样结合GC-MS定性分析能够快速建立柴胡果实的低温易挥发性成分GC-MS表征体系。     

现代离子色谱在测定痕量元素方面的进展

离子色谱自问世以来一直是分析化学领域快速发展的技术之一。文章介绍了现代离子色谱的一些发展情况,特别是固定相,抑制剂等两方面的技术更新,并就离子色谱和其他现代大型检测仪器联用在测定复杂基体中痕量、超痕量元素方面的进展进行了综述,着重于离子色谱与质谱联用测定阴离子和离子色谱与原子荧光联用测定阳离子两方面。     

A preconcentration and subsequent gas liquid chromatographic analysis method for trace volatiles

A glass column containing a porous polymer was used to concen-trate headspace volatiles from enzymatically mediated reactions and inserted directly into the injection port of a gas liquid chromatog-raphy (GLC) for elution and separation of adsorbed volatiles. The polymer column was placed in an entrainment system attached to a water aspirator at 30 psi to collect volatiles produced by the en-zymatic reaction. A useful chromatogram was obtained from 1 g of raw material by this method. Volatiles collected in this manner could be stored on the polymer matrix at ambient temperatures without deleterious effects for subsequent GLC analysis. Multiple columns of the same or different trapping material could also be used in the entrainment system. Paper Number 5523 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina 27650.     

Thermal decomposition processes in aromatic amine-based polybenzoxazines investigated by TGA and GC-MS

Three different aromatic amine-based polybenzoxazines are subjected to thermal decomposition in a thermogravimetric analyzer. The degradation products, which are volatile compounds evaporating out of the furnace as gases, are trapped and analyzed further by a gas chromatograph which is coupled with a mass selective detector (GC-MS). All the degradation products are separated by GC and come out at different retention times, as seen in the total ion chromatogram. All the compound's mass are selectively identified by MS. The chromatograms are divided into two regions; the low column temperature region containing low molecular weight and highly volatile compounds, and the high column temperature region containing higher molecular weight and less volatile compounds. The evolved gas analysis performed by GC-MS allows us to identify the molecular weight and also the structure of the volatiles. This information is then used to illustrate the processes occurring during the thermal decomposition of aromatic amine-based polybenzoxazines.     

Analysis of vegetable oil volatiles by multiple headspace extraction

Quantitative determination of the volatiles produced from oxidized vegetable oils is an important indicator of oil quality. Five vegetable oils, low-erucic acid rapeseed, corn, soybean, sunflower and high oleic sunflower, were stored at 60°C for four and eight days to yield oils with several levels of oxidation. Peroxide values of the fresh oils ranged from 0.6 to 1.8 while those of the oxidized oils were from 1.6 to 42. Volatile analysis by the multiple headspace extraction (MHE) technique, which includes a pressure and time controlled injection onto the gas chromatography (GC) column (a chemically bonded capillary column), was compared with that obtained by static headspace gas chromatography (SHS-GC). Several volatile compounds indicative of the oxidation of polyunsaturated fatty acids from the vegetable oils were identified and measured by MHE; pure compounds of twelve major volatiles also were measured by MHE, and peak area was determined. Multiple extractions of the oil headspace provided a more reproducible measure of volatile compounds than was obtained by SHS-GC. Concentration of all volatiles increased with increased oxidation as measured by peroxide value of the oil. Presented at the Annual American Oil Chemists' Society Meeting, May 8–12, 1988, Phoenix, AZ.     

塑料电子电气产品中四溴双酚A的微波辅助萃取-衍生气相色谱-质谱法测定

利用甲苯/甲醇(10:1,体积比)溶液微波辅助萃取塑料电子电气样品,用正己烷沉淀萃取液中的高聚物,以N,O-双(三甲基硅烷基)三氟乙酰胺为衍生化试剂,对萃取液进行衍生化反应,采用气相色谱-质谱总离子流和选择离子流对四溴双酚A进行定性定量测定。对衍生化时间、衍生化温度、衍生化试剂用量、沉淀试剂用量等前处理条件进行了优化,并进行了线性关系、回收率、精密度等试验。结果表明:本方法线性范围0.05～50mg/L,相关系数为0.9992,检测低限为2mg/kg,回收率在91.0%～97.9%之间,相对标准偏差小于7%。     

Aroma Release from Solid Droplet Emulsions: Effect of Lipid Type

Aroma compounds partition between the different phases of a food emulsion and the headspace but only those in the headspace are perceived. Phase transitions in the lipid droplets profoundly affect the position of the partitioning equilibria and hence headspace aroma concentration. The release of four volatile aroma compounds (ethyl butanoate, pentanoate, heptanoate and octanoate) from eicosane, hydrogenated palm fat or Salatrim^® emulsions stabilized with sodium caseinate were investigated as a function of fat crystallization, particle size and droplet concentration. For all compounds, the headspace aroma concentration in equilibrium with solid droplet emulsions was significantly higher than that in equilibrium with liquid droplet emulsions. The partitioning of volatile aroma compounds from emulsion does not depend on the type of liquid lipid, however, the interactions between solid lipid droplets and aroma compounds are significantly influenced by the nature of the crystalline fat. Notably, partitioning into the headspace was much lower for solid triglyceride droplet emulsions than for solid alkane emulsions. It was proposed that both residual liquid lipid in solid triglycerides and aroma co-crystallization with solid lipid could be responsible for higher aroma absorption by solid triglycerides.     

精油和芳香萃取物中残留苯含量的测定

建立了测定精油和芳香萃取物中残留苯含量的方法,分别考察了静态顶空和直接进样两种进样方式、两种不同固定相的色谱柱、氢火焰离子化检测器(FID)和质谱检测器(MSD)两种检测器。实验得出结论:对于挥发性较大的样品采取直接进样的方式进行测定,不易挥发的样品采用顶空进样方式。实验结果表明,在1×10-6～2.5×10-5浓度范围内,采用不同的组合,残留苯含量均具有良好的线性关系。     

色谱-质谱联用分析氟橡胶二段硫化挥发物

采用液上分析器,模拟出以胺类、酚类和过氧化物类为硫化剂的氟橡胶26-41胶料在二段硫化过程中生成的挥发物,色谱-质谱联用分析出该挥发物的组分为低碳有机氟化物、丙酮、苯、甲苯和吡啶类化合物等。认为不同配方的胶料,其二段硫化的挥发物有较大差异。该方法可用于研究不同硫化体系其他胶种的二段硫化挥发物。