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1.
采用固相微萃取与气相色谱联用技术,对塑料制品-保鲜薄膜、牛奶包装袋中的痕量挥发性有机物异丙醇、乙酸乙酯、丁酮、甲苯进行定量测定.该方法的线性范围大于l0^2数量级,检出限低于4.4ng/mL水平,相对标准偏差为2.3%-4.7%.方法灵敏度高、重现性较好.  相似文献   

2.
挥发性有机物(VOCs)影响车内空气质量和驾乘者的身心健康。自主研发的在线挥发性有机物质谱仪(SPI-MS 2000),实现了有机物分子的单光子电离,产生无碎片的分子离子,可实现秒级响应,仪器的质量分辨率优于800 FWHM,质量精度优于0.02 amu,对甲苯的测定限优于3μg/m^3,且在3~8000μg/m^3范围内有良好的线性关系。将该仪器应用于某客车车内空气的在线检测:在5 s内检测到20多种微克~毫克每立方米量级的有机物。该仪器在车内VOCs现场快速监测方面有广泛的应用前景。  相似文献   

3.
作者改进了气提法富集水中痕量挥发性有机物装置。研究了实验条件对水中痕量有机物富集的影响,并确定了最佳富集条件。以气提法富集气相色谱/质谱法(GC/MS)测定了水样中痕量挥发性有机物,取得了满意的结果。  相似文献   

4.
本文介绍了自行研制的浓缩器结构,并以气、液、固三种类型的样品进行了实际应用。实验表明,该装置是痕量挥发性有机物浓缩富集-气相色谱分析的有效手段。  相似文献   

5.
表面增强拉曼光谱(Surface-enhanced Raman Spectroscopy, SERS)是基于拉曼散射效应,通过把被分析有机物吸附在经特殊处理的粗糙金属表面,使有机物的拉曼散射信号增强的一种具有高灵敏度的分析技术。SERS技术能快速检测出痕量残留物质,在表面痕量残留检测领域有很大的应用价值。本文对SERS技术在痕量残留检测方面的发展及应用进行了综述,并对未来SERS技术在表面痕量残留快速检测方面的应用进行了展望。  相似文献   

6.
《化学通报》2006,69(5):399-400,350
[w049]挥发性有机物对流层大气化学过程研究进展ProgressesofTroposphericChemistryofVolatileOrganicCompounds姚立葛茂发乔志敏孙政王殿勋(中国科学院化学研究所大气环境化学室北京100080)挥发性有机物(VOCs)是大气对流层重要的痕量组分,可通过光解和与OH自由基、NO3自由基、  相似文献   

7.
HS/GC-MS法对卷烟包装材料中挥发性有机化合物的检测   总被引:4,自引:2,他引:2  
建立了一种用于测定卷烟包装材料中挥发性有机物(VOCs)的分析方法.采用三醋酸甘油酯为基质,利用顶空技术对样品进行前处理,并与气相色谱质谱(GC-MS)联用,用离子选择对17种挥发性有机物进行了定量分析.在优化的实验条件下,方法线性关系良好,17种挥发性有机物的相关系数均大于0.999,检出限为0.30 ~18 μg/m2,比全扫描的检出限低1 ~3个数量级.17种挥发性有机物的回收率为90% ~101%,相对标准偏差小于3.67%.该法简便、快速、重复性好、定性定量准确,适于大批卷烟包装材料中挥发性有机化合物的检测.  相似文献   

8.
从江苏省化学工业挥发性有机物污染控制实际情况,研究了优先控制挥发性有机物的筛选原则和筛选方法,建立了挥发性有机物的定量评估指标体系,通过综合评分法对主要挥发性有机物进行筛选和排序,在此基础上提出了33种(类)优先控制挥发性有机物名录,为江苏省《化学工业挥发性有机物排放标准》编制提供技术支撑。  相似文献   

9.
建立了同时检测软体家具面料中40种挥发性有机物的环境舱-热脱附-气质联用(ETC-ATD-GC/MS)检测方法。以Tenax TA吸附管吸附环境舱内不同面料中释放的挥发性有机物,经热脱附仪加热,将挥发性有机物脱附后随载气进入GC/MS进行定性和定量分析。考察了吸附管脱附温度、脱附时间,冷阱温度等不同参数对挥发性有机物的脱附效率的影响。结果表明,40种挥发性有机物在2~200 ng质量范围内呈良好的线性关系,相关系数在09949~0.9999之间,方法的检测限为0.011~0.277μg/m~3。方法回收率为88.0%~109.9%,相对标准偏差在1.5%~9.5%之间。方法适用于不同软体家具面料中挥发性有机物的定量分析。  相似文献   

10.
赵迪  沈铮  闫晓辉  吴大朋  丁坤  关亚风 《分析化学》2013,41(8):1153-1158
基于多孔膜萃取水中挥发性有机物和微捕集技术,构建了一套水中挥发性有机物(Volatile OrganicCompounds,VOCs)样品前处理装置,可自动、在线、连续完成水中挥发性有机物萃取、富集、热解析,传输给气相色谱分离检测。实验分别对膜萃取材料、萃取温度、萃取时间、吹扫气流速等进行了系统优化,并用于氯仿、1,2-二氯甲烷、四氯化碳、三氯乙烯、甲苯、四氯乙烯、乙苯、氯苯、苯乙烯9种挥发性有机物的检测。研究结果表明,采用膜萃取/微捕集装置,与气相色谱联用,在萃取温度60℃,萃取时间30 min,吹扫气流速8 mL/min条件下,采用氢焰离子化检测器(Flame ionization detector,FID),对氯代烃的检出限达到0.003~0.041μg/L,精确度为2.7%~13.0%,线性相关系数均大于0.9936,适用于在线检测水中挥发性有机物。  相似文献   

11.
In the past decade, we have witnessed rapid development of direct-injection mass spectrometric (DIMS) technologies that combine ever-improving mass and time resolution with high sensitivity and robustness. Here, we review some of the most significant DIMS technologies, which have been applied to rapid monitoring and quantification of volatile organic compounds (VOCs) and biogenic VOCS (BVOCs). They include MS-e-noses, atmospheric-pressure chemical ionization (APCI), proton-transfer-reaction mass spectrometry (PTR-MS), and selected ion-flow-tube mass spectrometry (SIFT-MS). DIMS-based MS-e-noses provide the possibility to screen large sample sets and may yield rich analytical information. APCI is a widespread ionization method and pioneered DIMS in environmental and flavor-release applications. SIFT-MS and PTR-MS allow better control of precursor-ion generation and hence of the ionization process. SIFT-MS puts the focus on control of the ionization process, while PTR-MS does so on sensitivity. Most (B)VOCs of interest can be efficiently detected and often identified by DIMS, thanks also to the possibility of switching between different precursor ions and the recent realization of time-of-flight-based equipments. Finally, we give selected examples of applications for each of the key technologies, including research in food-quality control (MS-e-nose), flavor release (APCI), environmental sciences (PTR-MS) and health sciences (SIFT-MS).  相似文献   

12.
13.
Proton-transfer-reaction mass spectrometry (PTR-MS) is a powerful technique for the real time trace gas analysis of volatile organic compounds (VOCs). However, quadrupole mass spectrometer (MS) used in PTR-MS has a relatively low mass resolution and is therefore not suitable for differentiating isobars. Furthermore, because of the lack of chemical separation before analysis, isomers can not be identified, either. In the present study, by varying the reduced-field E/N in the reaction chamber with a range of 50–180 Td in PTR-MS, we studied the product ion distribution (PID) of three sets of isobars/isomers, i.e. n-propanol/iso-propanol/acetic acid, propanal/acetone and four structural isomers of butyl alcohol. The profiles of the reduced-field dependence (PFD) of the PID under the chosen E/N-values show obvious differences which can be used to discriminate between these isobars/isomers thus enabling the titled method. Noticeably, we have observed that even the isomers, in the case of four structural isomers of butyl alcohol, which show little difference with each other at high reduced-field, can be discriminated easily at low reduced-field. Finally, two examples for the application of this method are discussed: (1) cyclohexanone was identified to be a major compound in the headspace of medical infusion sets; and (2) the differentiation and quantification of propanal and acetone in three synthetic mixtures with different ratios. This study presents a potential method to distinguish and quantify isobars/isomers conveniently in practical applications of PTR-MS analysis without additional instrumental configurations.  相似文献   

14.
The gastronomic relevance and high price of white truffle are related mainly to its unique aroma. Here we evaluate, for the first time, the possibility of characterizing in a rapid and non-destructive way the aroma of white truffles based on proton transfer reaction mass spectrometry (PTR-MS). We indicate that anonymous PTR-MS fingerprinting allows sample classification and we also compare qualitatively and quantitatively PTR-MS data with measurements made by solid-phase microextraction gas chromatography (SPME-GC) of the same samples under the same conditions. PTR-MS fragmentation data of truffle-relevant compounds are also published here for the first time. Most of the sulfur-containing compounds detected by GC and relevant for white truffle aroma have a high positive correlation with single PTR-MS peaks. Our work indicates that, after preliminary comparison with GC data, PTR-MS is a new tool for the rapid, quantitative and non-invasive characterization of white truffle by direct headspace injection without any pre-concentration.  相似文献   

15.
Because the optimum working pressure of ion funnel (IF) is very close to the typical operating pressure of a traditional drift tube for proton transfer reaction mass spectrometry (PTR-MS), it is possible to develop an IF drift tube for PTR-MS to improve the sensitivity. In this study, an ion funnel capable of functioning as a drift tube in a PTR-MS system was designed and studied by computer simulation. To optimize the geometrical and electrical parameters of the ion funnel, five ion funnel configurations were constructed. The merits and features of the respective ion funnels were evaluated, and the ion transmission characteristics were investigated and analyzed. An optimized ion funnel model was compared against the typical traditional drift tube that was used in PTR-MS for ion transmission, and it was found that the ion traveling trajectories in the ion funnel and traditional drift tube had different shapes and ion transmission efficiencies. Preliminary investigations revealed that this ion funnel improved the ion transmission efficiency by at least 10 times. The simulation and experiment results are helpful in guiding the design of an improved ion funnel to develop a PTR-MS system with higher sensitivity.  相似文献   

16.
We present a newly developed instrument that uses proton-transfer ion trap-mass spectrometry (PIT-MS) for on-line trace gas analysis of volatile organic compounds (VOCs). The instrument is based on the principle of proton-transfer reaction-mass spectrometry (PTR-MS): VOCs are ionized using PTRs and detected with a mass spectrometer. As opposed to a quadrupole mass filter in a PTR-MS, the PIT-MS instrument uses an IT-MS, which has the following advantages: (1) the ability to acquire a full mass spectrum in the same time as one mass with a quadrupole and (2) extended analytical capabilities of identifying VOCs by performing collision-induced dissociation (CID) and ion molecule reactions in the IT. The instrument described has, at its current status, limits of detection between 0.05 and 0.5 pbbv for 1-min measurements for all tested VOCs. The PIT-MS was tested in an ambient air measurement in the urban area of Boulder, Colorado, and intercompared with PTR-MS. For all measured compounds the degree of correlation between the two measurements was high (r 2 > 0.85), except for acetonitrile (CH3CN), which was close to the limit of detection of the PIT-MS instrument. The two measurements agreed within less than 25%, which was within the combined measurement uncertainties. Automated CID measurements on m/z 59 during the intercomparison were used to determine the contributions of acetone and propanal to the measured signal; both are detected at m/z 59 and thus are indistinguishable in PTR-MS. It was determined that m/z 59 was mainly composed of acetone. An influence of propanal was detected only during a high pollution event. The advantages and future developments of PIT-MS are discussed.  相似文献   

17.
The purpose of this short review is to describe the origins and the principles of operation of selected-ion flow-tube mass spectrometry (SIFT-MS) and proton-transfer-reaction mass spectrometry (PTR-MS), and their application to the analysis of biogenic volatile organic compounds (BVOCs) in ambient air, the humid air (headspace) above biological samples, and other samples. We briefly review the ion chemistry that underpins these analytical methods, which allows accurate analyses. We pay attention to the inherently uncomplicated sampling methodologies that allow on-line, real-time analyses, obviating sample collection into bags or onto traps, which can compromise samples.Whilst these techniques have been applied successfully to the analysis of a wide variety of media, we give just a few examples of data, including for the analysis of BVOCs that are present in tropospheric air and those emitted by plants, in exhaled breath and in the headspace above cell and bacterial cultures (which assist clinical diagnosis and therapeutic monitoring), and the products of combustion. The very wide dynamic ranges of real-time analyses of BVOCs in air achieved by SIFT-MS and PTR-MS - from sub-ppbv to tens of ppmv - ensure that these analytical methods will be applied to many other media, especially when combined with gas-chromatography methods, as recently trialed.  相似文献   

18.
Separation of inspiratory, mixed expired and alveolar air is indispensable for reliable analysis of VOC breath biomarkers. Time resolution of direct mass spectrometers often is not sufficient to reliably resolve the phases of a breathing cycle. To realise fast on-line breath monitoring by means of direct MS utilising low-fragmentation soft ionisation, a data processing algorithm was developed to identify inspiratory and alveolar phases from MS data without any additional equipment. To test the algorithm selected breath biomarkers (acetone, isoprene, acetaldehyde and hexanal) were determined by means of quadrupole proton transfer reaction mass spectrometry (PTR-MS) in seven healthy volunteers during exercise on a stationary bicycle. The results were compared to an off-line reference method consisting of controlled alveolar breath sampling in Tedlar® bags, preconcentration by solid-phase micro extraction (SPME), separation and identification by GC-MS. Based on the data processing method, quantitative attribution of biomarkers to inspiratory, alveolar and mixed expiratory phases was possible at any time during the experiment, even under respiratory rates up to 60/min. Alveolar concentrations of the breath markers, measured by PTR-MS ranged from 130 to 2,600 ppb (acetone), 10 to 540 ppb (isoprene), 2 to 31 ppb (acetaldehyde), whereas the concentrations of hexanal were always below the limit of detection (LOD) of 3 ppb. There was good correlation between on-line PTR-MS and SPME-GC-MS measurements during phases with stable physiological parameters but results diverged during rapid changes of heart rate and minute ventilation. This clearly demonstrates the benefits of breath-resolved MS for fast on-line monitoring of exhaled VOCs.
Figure Experimental setup showing bicycle ergometer and analytical pathways: Right side PTR-MS: identification of respiratory phases by means of the new algorithm. Left side: confirmation of PTR-MS data for exhaled isoprene by means of GC-MS analysis
  相似文献   

19.
Proton transfer reaction mass spectrometry (PTR-MS) has played an important role in the field of real-time monitoring of trace volatile organic compounds (VOCs) due to its advantages such as low limit of detection (LOD) and fast time response. Recently, a new technology of proton extraction reaction mass spectrometry (PER-MS) with negative ions OH as the reagent ions has also been presented, which can be applied to the detection of VOCs and even inorganic compounds. In this work, we combined the functions of PTR-MS and PER-MS in one instrument, thereby developing a novel technology called dipolar proton transfer reaction mass spectrometry (DP-PTR-MS). The selection of PTR-MS mode and PER-MS mode was achieved in DP-PTR-MS using only water vapor in the ion source and switching the polarity. In this experiment, ketones (denoted by M) were selected as analytes. The ketone (molecular weight denoted by m) was ionized as protonated ketone [M + H]+ [mass-to-charge ratio (m/z) m + 1] in PTR-MS mode and deprotonated ketone [M – H] (m/z m – 1) in PER-MS mode. By comparing the m/z value of the product ions in the two modes, the molecular weight of the ketone can be positively identified as m. Results showed that whether it is a single ketone sample or a mixed sample of eight kinds of ketones, the molecular weights can be detected with DP-PTR-MS. The newly developed DP-PTR-MS not only maintains the original advantages of PTR-MS and PER-MS in sensitive and rapid detection of ketones, but also can estimate molecular weight of ketones.
Graphical Abstract ?
  相似文献   

20.
多反应离子的质子转移反应质谱   总被引:1,自引:0,他引:1  
在无放射性辉光放电离子源内, 采用不同试剂气体进行放电, 为质子转移反应质谱(PTR-MS)新增了强度在105 cps量级的3种反应离子NH4+, NO+和O2+, 纯度大于95%; 测试了这3种反应离子的离子-分子反应特征. 采用H3O+, NH4+, NO+和O2+等4种反应离子对同分异构体丙醛/丙酮进行检测发现, H3O+和NH4+均不能区分的丙醛/丙酮可采用NO+或O2+进行区分. 结果表明, 增加反应离子不仅使PTR-MS的可检测有机物范围不再局限于质子亲和势(PA)大于H2O的有机物, 还提高了PTR-MS区分同分异构体的能力.  相似文献   

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