Rapid Simultaneous Determination of Volatile Organic Compounds in Mattress Fabric by Headspace–Gas Chromatography–Mass Spectrometry

An analytical method for simultaneously determining 32 volatile organic compounds in mattress fabrics based on static headspace coupled to gas chromatography and mass spectrometry detection was established. Samples were cut into 5?×?5?mm small pieces and placed in a 20?mL headspace vial at 90° for 30?min. To achieve the optimum conditions for the analysis, several parameters including the heating temperature, heating time, sample weight, and injection time were investigated. The results demonstrated that the most important parameter influencing the sensitivity of the analysis was the heating temperature. The optimum method showed good linearities with correlation coefficients ranged from 0.9944 to 0.9998. The limits of detection and quantification for the target compounds were in the ranges of 0.004–0.032 and 0.013–0.099?µg/?g, respectively. The method was successfully applied to determine the volatile organic compounds in six categories of mattress fabrics. The results showed that some volatile organic compounds were found, such as naphthalene, hexadecane, and 1,4-diisopropylbenzene. Moreover, the concentrations of 32 volatile organic compounds decreased following the order of jute, terylene, polyester, velboa, nylon, and cotton samples in the study. These results indicated that the method is fast, accurate, and successful for determining volatile organic compounds in mattress fabrics.     

山楂挥发性化合物的气相色谱-质谱分析

采用蒸馏－萃取法收集山楂果的挥发性化合物,通过气相色谱及气相色谱／质谱分析,鉴定了３２种化合物,占总峰面积的６１％～６８％。其中主要的１０种化合物是顺－３－己烯醇、顺－３－乙酸己烯酯、α－萜品醇、糠醛、己醇、乙酸己酯、壬醛、柠檬醛、３－戊烯－２－酮,反－２－癸烯醛等。     

Determination of breath gas composition of lung cancer patients using gas chromatography/mass spectrometry with monolithic material sorptive extraction

A gas chromatographic–mass spectrometric method with monolithic material sorptive extraction (MMSE) pretreatment was developed to determine the breath gas composition in lung cancer patients. MonoTrap silica monolithic and hybrid adsorbent was selected as the extraction medium during MMSE, given its strong capacity to extract volatile organic compounds (VOC) from exhaled gas. Under the appropriate conditions, high extraction efficiency was achieved. Using the selected ion‐monitoring mode, the limit of detection (signal‐to‐noise ratio 3) for the benzene series was 0.012–2.172 ng L^?1. The limit of quantitation (signal‐to‐noise ratio, 10) was 0.042–7.24 ng L^?1. The linearity range of the method was 4–400 ng L^?1. Average recovery of the benzene series at lower concentrations was 65–74% (20 ng L^?1). The relative standard deviation of benzene series contents determined within the linear range of detection was <10% of the mean level determined. Our proposed method is simple, rapid and sensitive, and can be competently applied to determine the breath gas composition of lung cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.     

基于呼气中特异性VOCs筛查的肺癌早期诊断与模型评估

采用气相色谱－质谱联用仪（GC－MS）检测了180例受试者的呼出气样品,包括79名肺癌患者和101名健康志愿者。每个受试者采集3个平行样品,以及1个室内空气样品。对所有呼气样品中检测的92种挥发性有机物（VOCs）进行定量分析。结合Mann－Whitney检验和正交偏最小二乘判别分析（OPLS－DA）模型筛选出10种肺癌患者呼气特异性VOCs,包括苯甲醛、顺式-2-丁烯、2-丁酮、萘、乙酸乙烯酯、乙烯、2,2,4-三甲基戊烷、3-甲基戊烷、己醛和2-甲基戊烷。利用统计学方法研究其在不同人群中的代谢差异和可能相关的代谢机制,通过建立机器学习模型验证候选标志物对疾病的诊断性能,结果显示,随机森林模型诊断的准确度、精准率、灵敏度和特异性分别为96.25%、96.21%、95.76%、96.67%,马修斯相关系数（MCC）为0.93,曲线下面积为0.96。上述10种化合物可作为肺癌患者的潜在呼气VOCs标志物,为肺癌的早期诊断提供了丰富的基础数据。     

Coupling Pervaporation-Gas Chromatography for Speciation of Volatile Forms of Selenium in Sediments

Abstract

A method for speciation of dimethylselenide (DMeSe), dimethyldiselenide (DMeDSe) and diethylselenide (DEtSe) in sediments based on a coupling between a pervaporation module, a preconcentration sorptive trap and a gas chromatograph-mass spectrometer is reported. The coupling is performed through a high pressure injection valve which allows two different operational modes: (a) analysis without preconcentration, in which analytes are directly driven from the pervaporation chamber to the injection port of the chromatograph, and (b) analysis with preconcentration in a trap, in which the analytes from the pervaporation chamber are first trapped on a Tenax minicolumn and then thermally desorbed and driven to the GC. This second approach improves the sensitivity compared to the direct coupling, reaching estimated absolute detection limits lower than 0.6 ng Se for each tested species. The method is applied to the determination of volatile organic selenium species in several sediments collected from different areas in the Southwest of Spain.     

Human exhaled air analytics: biomarkers of diseases

Over the last few years, breath analysis for the routine monitoring of metabolic disorders has attracted a considerable amount of scientific interest, especially since breath sampling is a non-invasive technique, totally painless and agreeable to patients. The investigation of human breath samples with various analytical methods has shown a correlation between the concentration patterns of volatile organic compounds (VOCs) and the occurrence of certain diseases. It has been demonstrated that modern analytical instruments allow the determination of many compounds found in human breath both in normal and anomalous concentrations. The composition of exhaled breath in patients with, for example, lung cancer, inflammatory lung disease, hepatic or renal dysfunction and diabetes contains valuable information. Furthermore, the detection and quantification of oxidative stress, and its monitoring during surgery based on composition of exhaled breath, have made considerable progress. This paper gives an overview of the analytical techniques used for sample collection, preconcentration and analysis of human breath composition. The diagnostic potential of different disease-marking substances in human breath for a selection of diseases and the clinical applications of breath analysis are discussed.     

Gas Chromatography‐Mass Spectrometry‐Basic Principles,Instrumentation and Selected Applications for Detection of Organic Compounds

Abstract

This mini‐review discusses the analytical technique of gas chromatography‐mass spectrometry (GC‐MS), specifically basic principles and instrumentations. The applications of GC‐MS to a number of studies for determining organic compounds from around the world are presented and highlight its universal use and acceptance. Selected applications show that GC‐MS is an integral and complimentary part of many field studies involving organic compound detection and determination.     

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.     

Oral malodor,assessed by closed-loop,gas chromatography,and ion-trap technology

A method is described for the analysis of volatile organic compounds in saliva and tongue coating samples. The techniue is based on an off-line preconcentration step by means of a closed-loop trapping system followed by gas chromatography-ion trap detection. With the closed-loop technique, the volatile organic compounds(VOCs) are released from the matrix and trapped on an adsorbent without interference of water. The VOCs are released from the adsorbent into the gas chromatograph by thermdesorption. After separation, identification of the compounds is performed by ion trap technology. By this technique 82 compounds could be demonstrated in saliva and tongue coating samples. The technique is also used to demonstrate the formation of volatile bacterial fermentation compounds when a protein substrate is added to tongue coating samples. It is considered a very promising tool in further research on oral malodor.     

顶空/气相色谱－质谱法测定婴幼儿食品中54种挥发性有机污染物

该文建立了同时测定婴幼儿食品中54种挥发性有机污染物的气相色谱－质谱方法。称取适量样品于20mL顶空进样瓶中,加入5mL氯化钠饱和溶液分散,加热振荡,目标物经DB－VRX毛细管色谱柱分离,单四极杆质谱全扫描模式测定。结果表明：奶粉基质中各化合物的线性范围为0.010~0.100mg/kg,定量下限均为0.010mg/kg;粉状辅食基质中各化合物的线性范围为0.010~0.250mg/kg,定量下限均为0.010mg/kg;泥状辅食基质中各化合物的线性范围为0.002~0.250mg/kg,定量下限均为0.002mg/kg。在不同加标浓度水平下,奶粉、谷物粉和果泥中各化合物的回收率为80.6%~130%,相对标准偏差（RSD）不大于19%。采用所建方法检测了35批次市售婴幼儿食品,9批次样品中共检出5种挥发性有机污染物。该方法前处理简单快捷,适用于婴幼儿食品中挥发性有机污染物的检测。     

用台式色谱-质谱仪同时进行原油芳烃色谱和色谱-质谱分析

用ＨＰ６８９０ＧＣ／５９７３ＭＳＤ仪器,一次进样同时测定原油、烃源岩抽提物中芳烃馏分的芳烃色谱和色谱－质谱信息,效果良好,在有机地球化学研究工作中很有实用价值,方法具有高效、经济等优点。     

Development of a Method for Determination of Volatile Organic Compounds (C6-C9) by Thermal Desorption-Gas Chromatography. Application to Urban and Rural Atmospheres.

ABSTRACT

An analytical method for the determination of 15 Volatile Organic Compounds (VOC): benzene, n-heptane, toluene, n-octane, chlorobenzene, ethylbenzene, m-xylene, o-xylene, p-xylene, isopropylbenzene, n-propylbenzene, n-decane, 1,4-dichlorobenzene, 1,3-dichlorobenzene and 1,2-dichlorobenzene, by thermal desorption coupled with gas chromatography (GC) was proposed. The flame ionisation detector (FID) and mass spectrometry (MS) detector were used. The variables that have an influence on the desorption process (time, inert gas flow and temperature) were studied, obtaining detection limit ranges from 15 to 120 pg (GC-FID), 3.8 to 32 pg (GC-MS, SIM mode) and 15 to 300 pg (GC-MS, SCAN mode). In order to detect possible VOC urban sources, samples were taken from 6 points in A Coruña (N.W. Spain) to analyse. Sampling time and flow rate were 30 minutes and 50 mL/min respectively. VOC profile and their total concentrations can be considered as typical of an urban area. Other samples were also obtained from a nearly rural zone to determine the influence of these VOC sources.     

Determination of Toluene and Ethanol in Urine by Headspace and Cryotrapping Gas Chromatography–Mass Spectrometry

Toluene is the major volatile organic compound found in glue and is often used as a hallucinogenic for abusers. Use with alcohol increases the risk of adverse effects from toluene exposure. In this study, a headspace and cryotrapping gas chromatography–mass spectrometry method was developed and validated for the determination of toluene and ethanol in urine. Experimental and instrumental variables were investigated to optimize the method for sensitivity. Excess sodium sulfate was used as the salting-out reagent before the headspace protocol. Linear least squares regression with a 1/x weighting factor was used to construct calibration curves from 0.002 to 0.4?µg?mL^?1 for toluene and 10 to 2000?µg?mL^?1 for ethanol. The correlation coefficients exceeded 0.9993. The limits of detection were 0.0005?µg?mL^?1 for toluene and 0.21?µg?mL^?1 for ethanol. Intraday and interday precisions were within 5.4 and 11.5%, while intraday and interday accuracies were between ?11.3 to ?4.0% and ?11.0 to 1.2%, respectively. The method validation results for selectivity and stability were satisfactory. The validation results were used to estimate the expanded uncertainty and the contribution of individual steps in the method for the quantification of toluene and ethanol. The relative expanded uncertainties were 14.1% for toluene and 4.6% for ethanol.     

A Study on VOCs Released by Lung Cancer Cell Line Using GCMS-SPME

The gas chromatography mass spectrometry (GCMS) with combination of Solid Phase Micro-extraction (SPME) was used to study the volatile organic compounds (VOCs) which emitted by the in-vitro cultured human cells and compared with documented volatile biomarker of lung cancer. For this purpose, the lung cancer cell (A549) and non-cancerous lung cell (WI38VA13) were cultured in identical growth medium, concurrently. The VOCs in the headspace of the cell cultures and the blank growth media (reference sample) were collected directly from the culture flask using SPME for 15minutes. The results show that two different volatile metabolites were screened out between A549 cells and Wi38VA13 cells. A549 cell found to emit 2 noticeable VOC which are decane and heneicosane. While for WI38VA13, the VOCs released were 1-Heptanol and heptadecane. The acquired VOCs were compared with the previous studies. The findings in this work conclude that the specific VOC of cells can be act as their odour signature and can be used to provide non-invasively screening of lung cancer using gas array sensor devices.     

热解吸-气相色谱法测定植物源挥发性有机物

以Tenax-TA、Carboxen 1000和Carbosieve SⅢ为采样管填充料,将植物源挥发性有机物吸附于采样管内,样品通过二次热解吸仪解吸后,随载气进入气相色谱仪,采用氢火焰离子化检测器(FID)测定,建立了利用二次热解吸仪与气相色谱联用技术测定植物挥发性有机物的分析方法。载气N2流速为30 mL/min,60℃下吹扫吸附管2 min,然后在250℃下解吸吸附管5 min,冷却1 min后,在275℃下解吸聚焦管3 min,样品经传输线进入气相色谱。气相色谱载气N2压力为190 kPa,FID检测器温度280℃;进样口温度225℃;初始柱温40℃,停留5 min,以2℃/min升温至120℃,保留1 min,然后以20℃/min升温至200℃,保留10 min。方法重现性好,精密度高,线性相关系数大于0.99;检出限均低于9×10-9g/L;解吸效率大于96%,适用于植物源挥发性有机物的测定。     

液相色谱-毛细管气相色谱/质谱离线联用分析烟草中的挥发性及半挥发性成分

建立了一种用于烟草样品中挥发性、半挥发性成分分析的液相色谱-毛细管气相色谱/质谱(LC-CGC/MS)离线联用方法。研究了LC-CGC/MS的分离机理。LC分析选用氨基分析柱(250 mm×2.0 mm, 5 μm)作为分析柱,正己烷-二氯甲烷-乙腈(90:6.6:3.4, v/v/v)作为流动相,对挥发性、半挥发性成分进行分离,收集得到5个馏分,并存放在5个氮吹瓶中。多次进样并收集相同时间段的馏分,氮吹浓缩至1 mL,然后分别进行CGC/MS分析,所用的CGC柱为DB-5MS(60 m×0.25 mm×0.25 μm)。结果显示,与直接采用CGC/MS分析相比,采用LC-CGC/MS分析复杂样本的效果更好,定性的可靠性更高。