顶空-气相色谱法检测皮革中挥发性有机物

采用顶空-气相色谱法对皮革中的挥发性有机化合物(VOCs)进行检测,其中顶空仪中样品加热温度为120℃、加热时间5h,样品中挥发出的VOCs归一为丙酮含量进行计算。结果表明,所测的34块皮革样品中,VOCs含量范围在60~190μgC/g之间。试验结果反映了目前皮革中VOCs的含量现状。     

顶空气相色谱法测定食品包装复合膜中挥发性有机物

目的建立1种利用岛津GC-2010 plus气相色谱仪及Equity-1色谱柱用于食品包装复合膜中常见15种挥发性有机物(苯类、酯类、酮类、醇类等)含量的顶空-气相色谱检测方法,为有效检测挥发性有机物提供参考。方法采用顶空-气相色谱法,选用Equity-1(30m×0.53mm×5.0μm)的毛细管色谱柱进行各挥发性有机物的分离测定。结果所建立的方法分离效果理想,该法在含量0.01~1.00 mg/m2线性关系良好,15种挥发性有机物的线性相关系数均大于0.999(除了邻二甲苯为0.998外),加标回收率为82%~111%,相对标准偏差(n=5)为2.9%~7.1%,检出限均达到10-3数量级。结论所建立的岛津色谱仪方法能够满足实际分析的要求。     

顶空气相色谱法测定食品包装复合膜中 挥发性有机物

目的 建立1 种利用岛津GC-2010 plus气相色谱仪及Equity-1色谱柱用于食品包装复合膜中常见15 种挥发性有机物（苯类、酯类、酮类、醇类等）含量的顶空-气相色谱检测方法,为有效检测挥发性有机物提供参考。方法 采用顶空-气相色谱法,选用Equity-1（30 m×0.53 mm×5.0 μm）的毛细管色谱柱进行各挥发性有机物的分离测定。结果 所建立的方法分离效果理想,该法在含量0.01~1.00 mg/m2线性关系良好,15 种挥发性有机物的线性相关系数均大于0.999（除了邻二甲苯为0.998外）,加标回收率为82%~111%,相对标准偏差（n=5）为2.9%～7.1%,检出限均达到10-3数量级。结论 所建立的岛津色谱仪方法能够满足实际分析的要求。     

顶空-气相色谱/质谱法测定食品包装纸中挥发性有机物的残留

利用顶空-气相色谱/质谱法同时测定食品包装用纸中17种挥发性有机物残留量。试验显示:17种挥发性有机物(乙醇、异丙醇、正丁醇、丙酮、丁酮、己醛乙酸乙酯、乙酸异丙酯、乙酸丁酯、丙二醇甲醚、乙酸正丙酯、苯、甲苯、间二甲苯、对二甲苯、苯乙烯、邻二甲苯、乙酸乙酯)均可高效分离;各组分标准曲线的相关系数R2均大于0.999 5,加标回收率在87.1%~103.8%之间,相对标准偏差(RSD)均不大于5.6%(n=6),检出限均低于0.01mg/m2。该法具有前处理简单,分离效果好,回收率和精密度高等优点,能够满足食品包装用纸中挥发性有机物检测要求。     

静态顶空-气相色谱法同时测定葡萄酒中12种挥发性成分

目的 建立一种静态顶空-气相色谱法同时测定葡萄酒中12种挥发性化合物的分析方法。方法 取葡萄酒5.00 mL于20 mL顶空瓶中, 加入2.00 g氯化钠, 顶空进样, 经强极性毛细管色谱柱分离, 氢火焰离子化检测器检测, 以保留时间定性, 内标法定量。结果 12种挥发性成分在相应质量浓度范围内线性关系良好, 相关系数均大于0.990, 定量限为0.04~9.49 mg/L, 回收率为70.43%~98.75%, 相对标准偏差为0.87%~9.51% (n=6)。结论 本方法无需复杂样品前处理即可实现葡萄酒中12种挥发性成分的定性与定量, 能够有效提高分析效率, 且简便快速、成本低, 可以为葡萄酒的质量控制和检验提供一种新方法。     

顶空-气相色谱法测定啤酒中酒精度

采用顶空进样,毛细柱气相色谱法测定啤酒中乙醇含量,样品在80℃下平衡20min进样,氢火焰离子化检测器检测,外标法定量,结果表明,在酒精浓度为1%~5%范围內加标回收率为98%~106%,RSD≤5.9%,本法适用于啤酒中乙醇的测定,快速、准确。     

顶空-气相色谱法检测鞋材中丙烯腈单体残留量

建立了鞋材中丙烯腈单体残留量测定的顶空气相色谱方法。样品经N,N-二甲基甲酰胺萃取后,在极性柱上进行分离,选用氢离子火焰检测器检测,外标法定量分析。丙烯腈在50~1000mg/kg样品含量范围内线性良好,检出限为15mg/kg。选用常用鞋材锦纶、腈纶、鞋用胶粘剂、ABS橡胶、丁腈橡胶,在4个浓度水平进行添加试验,样品加标回收率在85.6%~109.5%,相对标准偏差1.98%~3.98%(n=7)。本方法操作简单快速,重现性好,准确度高。     

静态顶空-气相色谱法测定酱香型白酒中挥发性香气成分研究

通过实验比较HP-INNOWAX、CP-WAX57 CB、ZKAT-LZP930.2色谱柱在白酒香气成分检测中的应用效果,同时针对顶空平衡温度、平衡时间以及样品中离子浓度条件等进行系统优化。结果表明,色谱柱HP-INNOWAX;初始温度35℃,保持1 min,以2℃/min升温至120℃,再以8℃/min升温至200℃;进样口温度230℃,检测器温度250℃;顶空平衡温度为60℃,平衡时间为30 min,NaCl浓度为0.4 g/mL。在此条件下操作,能获得对白酒中十几种主要香气成分的定性定量分析效果。     

卷烟包装纸中挥发性有机化合物(VOCs)的顶空-气相色谱分析

采用顶空-气相色谱法分析了卷烟包装纸中的16种挥发性有机化合物(VOCs),方法快速简便,准确可靠。对部分国内卷烟包装纸进行了检测,并对卷烟包装纸的VOCs现状进行了讨论。      

顶空-气相色谱法测定木耳中的磷化铝残留量

目的建立木耳中磷化铝残留量的顶空-气相色谱检测方法。方法将样品称量于顶空进样瓶中,加入硫酸溶液,使磷化铝与酸反应生成磷化氢,用气相色谱-氮磷检测器检测磷化氢的含量,得到样品中磷化铝的含量。结果磷化铝在0.05~5.00 mg线性关系良好,相关系数0.995,加标回收率在83.4%~112.6%,相对标准偏差为9.4%~10.2%之间,方法检出限为0.02 mg/kg。结论该方法快速简便、灵敏度高、准确性好,满足相关法规的限量要求,可用于木耳中磷化铝含量的实际检测工作。     

顶空气相色谱法同时测定食品包装材料13种溶剂残留量

该研究建立一种可同时测定食品包装材料中13种溶剂残留的顶空气相色谱检测方法。对顶空平衡温度、平衡时间进行研究;结果表明,平衡温度为100℃、平衡时间为30 min时,选用Stabilwax(30 m×0.25 mm,0.25μm)毛细管色谱柱能得到很好分离;该法检出限范围为0.008⁰.016 mg/m2,在0.0250.016 mg/m2,在0.025⁰.5 mg/m2范围内线性关系良好,相关系数均大于0.996,平均加标回收率为90.3%0.5 mg/m2范围内线性关系良好,相关系数均大于0.996,平均加标回收率为90.3%⁹9.5%,相对标准偏差为1.59%99.5%,相对标准偏差为1.59%⁵.96%。该法简便、快速、准确,可适用于对复合包装膜、袋中残留溶剂进行同时、快速测定。     

顶空固相微萃取-气相色谱-质谱联用法测定口虾蛄挥发性风味成分

采用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术,以口虾蛄为试材,对其挥发性风味成分进行分析。本研究优化了萃取头、萃取时间、萃取温度、加盐量等HS-SPME条件,结果表明:最优条件为萃取头65μm PDMS/DVB,时间50 min,温度50℃,加盐量0.16 g/mL。对口虾蛄的挥发性风味成分进行检测分析,经NIST质谱数据库检索和文献对照,采用面积归一化法测定各种成分的相对含量。共检出52种成分,包括酸类10种,N/O/S类化合物5种,醛类9种,芳香类6种,烃类6种,萜类6种,醇类4种,酯类4种,酮类2种。利用相对气味活度值(ROAV)确定了口虾蛄的特征挥发性风味成分,结果显示,其包括(E)-2-癸烯醛、月桂醛、1-辛烯-3-醇、2,3-辛二醇、2-乙酰基吡啶、三甲胺、壬醛、柠檬烯、戊醛、苯甲醛、萘、肉豆蔻醛,苯乙醛、2,3-丁二酮、2-十二醇、2-癸酮、庚醛、苯丙噻唑和2-乙酰噻唑共19种。     

用气相色谱法预测挥发性有机试剂的沸点

根据不同结构基团的挥发性有机试剂在不同极性气相色谱柱上的保留行为,用多元线性回归(MLR)方法,建立了挥发性有机试剂沸点与不同极性色谱柱上保留时间之间的关系模型,并根据各模型相关系数与概率值定量说明了模型中不同参数引入时的统计意义.结果表明,与单一极性色谱柱上的保留时间相比,采用不同极性色谱柱上的保留时间,可以更好地预测有机试剂的沸点,并且更具统计学意义.     

顶空-气相色谱法测定塑料食品包装袋中6种苯系物残留量

采用顶空-气相色谱法对食品塑料包装材料中可能残留的苯系物(苯、甲苯、邻二甲苯、间二甲苯、对二甲苯、异丙苯)进行分析。方法采用FFAP色谱柱分离,氢火焰离子化检测器FID检测,6种苯系物能够完全分离,线性较好,方法的检出限可达2.67μg/m2,7次测定相对标准偏差在0.89%～1.95%,样品加标回收率苯系物介于64.6%～97.1%。测定了10种塑料包装材料中的苯系物残留量,方法简便、快速、重现性好,完全能满足塑料包装材料中苯系物残留量的分析。     

Production of volatile organic compounds by apples

There is great variation in the rate at which different apple cultivars produce volatiles. The rate of production of volatiles, in terms of loss of carbon, is some 0.3–1.0% of the loss of CO₂; depending on conditions of storage, some 50–95% of the carbon lost as volatiles is accounted for by ethylene. Increase in concentration of CO₂ in the storage atmosphere reduces the rate of production of volatiles. Reduction of the oxygen concentration to a low level has the same effect, and ethylene production ceases in the complete absence of oxygen. The peel of the fruit is more active in production of ethylene than is the pulp; the rate of production is greater for small apples than for large. When the volatiles are removed from the storage atmosphere, the rate of production increases. The incidence of superficial scald, and the shape of the time/rate graph for ethylene are related. This could be due to an effect of climate during the growing period, affecting the porosity of the peel.     

Production of volatile organic compounds by pears

There is considerable variation between the rates of production of volatile organic compounds by different cultivars of pears, as has been shown for apples; the rates are lower in controlled atmosphere (C.A. ) storage than in air. When pears which have been cold stored, in air or in C.A. are ripened at a higher temperature, the rate of evolution of ethylene rises rapidly to a high value, but subsequently declines as the pears develop overripe symptoms.     

Analysis of volatile organic compounds in mainstream cigarette smoke

Mainstream cigarette smoke is a complex aerosol containing more than 4400 chemicals. The proliferation of new brands has necessitated development of faster and more reliable methods capable of analyzing a wide range of compounds in cigarette smoke. Although the International Agency for Research on Cancer has classified whole cigarette smoke as a human carcinogen, many of the individual chemicals are themselves highly biologically active as carcinogens, teratogens, or have implications for cardiovascular disease. Among these chemicals are many volatile organic compounds (VOCs), e.g., benzene, ethylbenzene, and styrene. To analyze VOCs in mainstream cigarette smoke, we developed a novel headspace collection technique using polyvinylfluoride bags for sample collection followed by cannula transfer to evacuated standard 20-mL auto sampler vials. Coupling collection of the vapor-phase cigarette smoke with automated analysis by solid-phase microextraction and gas chromatography/mass spectrometry enabled us to routinely quantify selected VOCs in mainstream cigarette smoke. This technique has similar reproducibility to previous cold trap and impinger collection methods with significantly higher sample throughput and virtually no solvent waste. In this report we demonstrate the method's analytical capabilities by quantitatively analyzing 13 selected VOCs in mainstream cigarette smoke from top-selling domestic brands.     

Analysis of volatile compounds of eucalyptus honey by solid phase extraction followed by gas chromatography coupled to mass spectrometry

Solid-phase extraction (SPE) followed by gas chromatography coupled to mass spectrometry has been used for the analysis of volatile compounds of eucalyptus honey. Different amounts of honey and dichloromethane were employed to optimize solid-phase extraction conditions. The best result was obtained with 20 g of honey eluted with 60 mL of dichloromethane. This method presented a good precision for volatile compounds usually found in honeys and allowed the quantification of 35 volatile compounds (terpenes and derivatives, furan and pyran compounds, ketones, benzene compounds, acids, and norisoprenoids) of eucalyptus honey.