顶空-气相色谱法测定水样中10种挥发性有机物

对顶空-气相色谱法测定水中10种挥发性有机物进行了研究,分别是苯、甲苯、1,2-二氯乙烷、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯、氯苯和苯乙烯。对实验条件进行了优化,并对方法的检出限、线性范围、精密度及准确度进行了考察。结果发现,该方法对待测组分具有灵敏度高,线性范围宽、准确度高等优点。     

顶空-气相色谱法测定食品纸盒包装材料中挥发性有机物

建立了一种顶空-气相色谱法测定食品纸盒包装材料中23种挥发性有机物的方法,主要检测甲醇、乙醇、异丙醇、丙酮、乙酸甲酯、正丙醇、乙酸乙酯、丁酮、苯、乙酸异丙酯、正丁醇、丙二醇甲醚、乙酸正丙酯、甲苯、丙二醇乙醚、4-甲基-2-戊酮、乙酸丁酯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯、环己酮等23种挥发性有机物。量取面积为20.0cm×5.0cm的包装材料,并将其卷成圆筒状,立即放入20mL顶空瓶中,加入1mL三醋酸甘油酯,密封,上机。23种挥发性有机物的相关系数均大于0.998,方法回收率在94.3%~102.7%之间,重现性较好,相对标准偏差(RSD)在1.52%~3.27%之间,最低检出限为0.001mg/m2。该方法简单、快速、准确、灵敏度高,完全能够满足食品纸盒包装材料中挥发性有机物的定量分析。     

顶空-气相色谱法对塑料中总碳挥发性有机物测试研究

研究了顶空-气相色谱法测定塑料中总碳挥发性有机物(TVOC)的方法。对样品平衡时间及平衡温度进行了优化,探讨了样品颗粒大小及载气对测试结果的影响。试验结果表明:以氮气和氦气作为载气时,二者测得的TVOC的线性相关性良好,均在0.9999以上;以氮气为载气,在120℃条件下平衡5 h做重复性和回收率试验,测得样品的重现性小于5%,回收率为107%。不同样品颗粒大小对测试结果影响很大。     

顶空-气质联用色谱法测定空气清新剂中可挥发性有机物含量

建立气质-顶空自动进样系统联用测定空气清新剂中37种可挥发性有机物含量的检测方法。对样品的取样方法和气质条件进行优化。在优化的条件下,样品中各个可挥发性有机物得到良好的分离,并以外标法定量。本方法精密度高,线性相关系数不小于0.996;加标回收率为80%～120%; RSD均小于10.0%;最低检出限为0.003～3.06μg/g。     

顶空/气相色谱法测定固体废物中的挥发性有机物

研究采用顶空前处理技术处理固体废物,用具火焰离子化检测器的气相色谱来分析测定固体废物中37种挥发性有机物（VOCs）。实验结果表明：在一定的静态顶空条件和气相色谱条件下,37种VOCs的线性相关性良好,都在0.99以上,相对标准偏差在2.6%～19.6%之间,实际样品加标回收率在20.3%～97.3%之间,检出限在0.002～0.031 mg/kg之间。     

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%。     

顶空气相色谱法测定药品包装中挥发性有机物

利用顶空技术,结合毛细管气相色谱法同时测定了药品包装袋中的8种挥发性有机物,方法具有分离效果好、操作简单、精密度高、检出限低等优点,可以作为药品包装袋中挥发性有机物的检测方法。     

自动顶空/气相色谱法测定再生PET树脂中3种挥发性有机物

建立了一种测定再生聚对苯二甲酸乙二醇酯(PET)树脂中乙醛、苯和D-柠檬烯含量的自动顶空/气相色谱分析方法。经毛细管色谱柱分离后,利用氢火焰离子化检测器(FID)检测上述3种挥发性有机物(VOCs)的含量。结果表明:乙醛、苯和D-柠檬烯均可以很好地分离,样品加标回收率为92%~105%,相对标准偏差(RSD)在1.94%~5.22%间,标准曲线的相关系数均超过0.995,最低检出限为0.001μg/g。该方法操作简捷、结果准确、灵敏度高、重复性好,适合再生PET树脂中3种VOCs的测定。     

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。     

车用聚氨酯泡沫材料VOC及气味改进综述

分析了车用聚氨酯泡沫材料气味来源,综合概述了当前车用聚氨酯泡沫材料挥发性有机化合物(VOC)和气味控制技术方面研究进展.首先以聚氨酯泡沫材料两大原料即聚醚多元醇及异氰酸酯为对象,从低气味聚醚多元醇的开发和异氰酸酯单体替代等方面介绍了降低聚氨酯泡沫VOC及气味的方法;其次从生产聚氨酯泡沫的各种助剂,包括催化剂、硅酮表面活...     

座椅总成VOC挥发性能的改进

为解决汽车座椅总成挥发性有机化合物(VOC)苯乙烯和甲醛的挥发量超标问题,从座椅的组成材料分析了污染物的来源,采用高效液相色谱仪与气相色谱-质谱联用仪对座椅总成VOC挥发量进行检测与分析。结果表明,座椅中的发泡材料造成了苯乙烯、甲醛超标,进一步分析可知发泡中的接枝聚醚与普通聚醚对座椅苯乙烯和甲醛的贡献最大。通过更改合成接枝聚醚的乙烯基单体与合成普通聚醚中的抗氧化剂使座椅总成满足VOC挥发性能要求,且座椅的成型工艺不受影响。     

降低聚氨酯泡沫用聚醚多元醇VOC技术简介

简要介绍了聚氨酯泡沫及其原材料聚醚多元醇中挥发性有机物(VOC)的来源及检测方法。从选择新型催化剂体系、改进聚合工艺、改进后处理工艺及在聚醚多元醇中添加稳定剂等方面详细介绍了降低聚醚多元醇VOC含量的技术;同时从脱除残留单体及溶剂、选择新型链转移剂、选择新型自由基引发剂等方面详细总结了降低聚合物多元醇(POP)中VOC含量的技术。     

活性氧化锌在轿车门窗密封条海绵胶中的应用

试验研究在轿车用门窗密封条海绵胶中以活性氧化锌减量替代普通氧化锌并减小易产生亚硝胺的促进剂用量的效果。结果表明，以活性氧化锌等量或减量替代普通氧化锌，不改变配方其它组分及其用量，当胶料完全充满型腔时，EPDM海绵胶的最小门尼粘度增大，t5和t35明显缩短，硫化仪数据变化不大；当胶料部分充满型腔时，EPDM海绵胶的硫化仪数据变化不大。以活性氧化锌减量替代普通氧化锌且不使用易产生亚硝胺的促进剂TDEC-70和TMTD-80，EPDM海绵胶的最小门尼粘度略有增大，t5和t35略有缩短，而硫化胶的高温压缩永久变形明显下降，气味减小。     

Sources of error in VOC determination via EPA method 24

Forty-five paint samples having volatile organic content (VOCs) ranging from 7 to 562 g/L were prepared and tested for VOC according to EPA Method 24. In addition, all individual raw materials utilized in preparing the paints were also tested for their VOCs. There were significant differences between claimed and measured VOCs for both raw materials and finished paints. The measurement error for VOC of finished paints was eight percent. This error increased exponentially as the VOC declined below about 250 g/L, reaching about 200% at VOCs below 50 g/L. The range of error also increased exponentially below about 250 g/L, reaching 1000% below 50 g/L. The major sources of VOC error in all cases were in the water and nonvolatile determinations. Presented at the 78th Annual Meeting of the Federation of Societies for Coatings Technology, on October 18–20, 2000, in Chicago, IL. 430 W. Forest Ave., Ypsilanti, MI 48197.     

Development of a test method using a VOC analyzer to measure VOC emission from adhesives for building materials

A volatile organic compound (VOC) analyzer is a portable device to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styrene. With the VOC analyzer, a semiconductor gas sensor eliminates the need for the carrier gas which is required for conventional gas chromatography. In addition, since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. Compared with other measurement methods, the VOC analyzer is useful for measuring toluene, ethylbenzene, xylene and styrene in new buildings because of its ease in obtaining field results and repeating the test. For easy, fast and economic testing of total (TVOC) emission from adhesives used for building materials, we developed a test method using the VOC analyzer and compared its measurement of VOC emissions from building materials such as adhesives, paints and wood-based panels with that of the 20-l chamber method, which is the standardized test method in Korea. There was a good correlation between the TVOC emission concentrations determined by the VOC analyzer and the TVOC emission factor (EF) by the 20-l chamber. Based on this good correlation, the VOC analyzer is expected to gain widespread use in the manufacturing field application where a quick and easy test for VOC emission from adhesives for building materials is required. Furthermore, the VOC analyzer offers the potential to become an easier, faster and more economical technique than the currently used standard methods.     

Dimensional analysis of foam drainage

Dimensional analysis of the process of steady drainage of liquid from foam has shown that, if surface and inertial effects are neglected, the drainage rate non-dimensionalised as a Stokes-type number may be described by a function of the liquid volume fraction only. In addition it is demonstrated that a simple power law relationship between these two quantities is a good approximation to channel-dominated and node dominated foam drainage models and that the approach enables the prediction of the dependency of drainage upon bubble size. The power law approach requires two adjustable constants which is the minimum required since a priori estimates of both surface shear viscosity and viscous losses in the vertices of the foam are problematical. In addition, a simple dimensionless parameter has been introduced that can modify the power law model to take into account capillary suction so that transients in one-dimensional drainage problems can be modelled.     

VOC testing comparison: EPA method 24 versus the cal poly pomona method

A new method for water determination of latex paints that gives reliable and precise results is presented. This method agrees with the results obtained using the traditional Karl Fischer titrations of EPA Method 24; therefore eliminating the need for Karl Fischer titrations. Equipment needs are minimal and the procedure is performed quickly and conveniently. Hopefully, in the future EPA Method 24 will not be the only method accepted by regulatory agencies. Until that time, however, this new method will be useful for quality control and assurance, in-house regulatory compliance monitoring, and research and development purposes. Presented at the 75th Annual Meeting of the Federation of Societies for Coatings Technology, on November 4, 1997, in Atlanta, GA. Person to whom correspondence should be sent: 3366 Somis Dr., Riverside, CA 92507.     

Comparative analysis of two foam models

Calculated results are compared for several one-dimensional self-similar interactions of shock waves with a water foam. The results are calculated using 1) a cell model in which the foam is treated as a porous medium which is impenetrable to gas and 2) a single-velocity (equilibrium) model of a multicomponent medium. It is found that pulsations excited in foam bubbles by a shock wave must be considered.Chelyabinsk State University, Chelyabinsk. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 3, pp. 22–28, May–June, 1995.     

吸附-光催化法用于降解室内VOC的研究进展

吸附-光催化法因其高效、便捷、无污染等特点,在室内挥发性有机物(VOC)治理领域拥有着广阔的应用前景。本文介绍了吸附-光催化降解VOC机理;总结了近年来常用的固定化TiO₂的制备方法,以及各自的工艺流程、适用范围和存在的问题;综述了反应环境(风速、初始浓度、温度、相对湿度)对吸附-光催化降解率的影响。分析表明,在选择TiO₂固定化工艺时,应当根据吸附剂基材的表面基团、孔隙结构和亲疏水性等特征合理经济地确定制备方法;在探讨反应环境对室内VOC降解率的影响规律时,应综合考虑VOC自身特性和反应器类型等实验条件以得到不同条件下的最佳环境参数。最后指出,低温成膜的制备方法以及对反应环境如何影响低浓度多组分VOC降解的研究将成为今后的发展趋势。