Porapak Q色谱柱在大型乙烯联合生产装置分析中的应用

介绍了气相色谱法Porapak Q填充色谱柱在大型乙烯联合生产装置分析中的应用.Porapak Q分别作为预柱及分析柱,主要是在乙烯、丙烯产品中微量CO、CO2,C3以下不凝气,乙烯、丙烯产品中微量氢气,环氧乙烷/乙二醇循环气,槽车中氧含量,丙酮产品中杂质及环氧乙烷中CO2分析中的广泛应用.     

纸质食品包装材料迁移测试研究用固体食品模拟物的选择

利用气相色谱-质谱联用技术(GC-MS),对市面上常用纸质包装材料进行包装的食品——米粉、大米、脱脂奶粉、白砂糖,以及目前研究常用的、价格昂贵的食品模拟物Porapak的热稳定性与对各种模拟污染物的吸收性能进行了分析,以寻求代替Porapak用于分析纸质食品包装材料迁移测试的最佳食品模拟物。研究结果表明,在100℃时,出现了大米熟化、白砂糖热分解、脱脂奶粉焦化的现象,与其他食品相比,米粉的热稳定性最好;对75℃时各食品(模拟物)对模拟污染物的吸收性能依次为:Porapak米粉脱脂奶粉白砂糖大米,米粉与Porapak的吸收性能最接近,可以利用米粉代替Porapak,作为食品模拟物进行迁移测试实验。     

气相色谱法快速测定高纯度二氧化硫气体中水分含量

采用气相色谱法,运用Porapak Q固定相,在柱温100℃时可测定产品SO2气体中水分含量。此方法分离效能高,稳定性好,结果准确。     

Porapak-Q collection of airborne organic compounds serving as models for insect pheromones

Organic compounds with properties resembling those of insect pheromones can be removed from an airstream by absorption on Porapak Q and recovered from the absorbent by extraction. When this procedure is applied to aeration of live insects, the Porapak extract represents a concentration of the chemical message.     

Development of a bioluminescence assay for aldehyde pheromones of insects

A newly developed bioluminescent assay was used to measure quantitatively the amount of (E)-11-tetradecenal, the major component of the sex pheromone of the spruce budworm, trapped on Porapak Q^®. The bioluminescent response was linearly related to the amount of aldehyde either deposited on the absorbent or trapped from an airstream. However, the recovery of pheromone from Porapak was dependent on whether the air was prefiltered (through Porapak) or taken directly from the atmosphere. Furthermore, pheromone on Porapak was lost with time during the flow of air through the absorbent, indicating that trapping of aldehyde pheromone should be conducted for short periods of time for optimal recoveries. The applicability of the assay system for the rapid and direct measurement of the release rates of aldehyde pheromone lures was demonstrated for pheromone lures used for baiting spruce budworm traps.This investigation was supported by the U.S.D.A. Forest Service Program entitled Canada United States Spruce Budworms Program (23–345) and the Medical Research Council of Canada (MT-4314).     

Sex pheromone components and calling behavior of the female dermestid beetle,Trogoderma variabile Ballion (Coleoptera: Dermestidae)

Females of the dermestid beetle,Trogoderma variabile Ballion, exhibit a diel pattern of calling behavior. A potent sexual excitant and attractant for the male beetles can be collected on Porapak Q during aeration of female beetles, but cannot be detected in extracts of macerated females. The attractant has been identified as (Z)-14-methyl-8-hexadecenal. Of the five additional compounds previously identified as attractants in otherTrogoderma species, only two were found; (Z)-14-methyl-8-hexadecen-1-ol is present in extracts of macerated female beetles, but not in extracts of Porapak Q, and -caprolactone is present in extracts of Porapak Q. Three collection procedures were necessary to ensure that all the pheromone components had been isolated. Synthetic (Z)-14-methyl-8-hexadecenal elicits attraction and sexual arousal inT. Variabile males.Mention of a commercial or proprietary product in this paper does not constitute an endorsement of that product by the USDA.     

GC-126PDD氦离子化气相色谱仪分析COS杂质的应用试验

羰基硫(化学式:COS),可替代溴甲烷和磷化氢而被用作熏蒸剂。有机合成中,用于合成硫代酸、取代噻唑、杀虫剂巴丹、除草剂燕麦敌、杀草丹等。石化工业中用作在线仪表的校正气、标准气。     

Porapak QS固定相的色谱性能研究

针对国外Porapak QS的色谱性能进行了研究，测定了极性常数(麦氏常数)，提出在柱温170℃测定其常数的方法，测定了热分析曲线和17种物质的相对保留值；对柱温与保留值、关系进行了研究。     

Host selection byHylemya antiqua (Meigen)

Volatile components ofAllium cepa L, trapped in and recovered from Porapak Q, were separated by gas-liquid and thin-layer chromatography. Fractions eliciting oviposition fromHylemya antiqua (Meigen) were analyzed by combined gas chromatography-mass spectroscopy (GC-MS) and were found to contain saturated and unsaturated disulfides. Authentic samples of the identified components were obtained by synthesis and tested for oviposition response byH.antiqua. Three new attractants and oviposition stimulants forH. antiqua are methyl propyl disulfide,cis-propenyl propyl disulfide, andtrans-propenyl propyl disulfide. All were present in greater proportion in the volatiles from fresh onions than from stored onions. Dimethyl disulfide, methylcis-propenyl disulfide, and methyltrans-propenyl disulfide did not elicit significant oviposition fromH. antiqua.Diptera: Anthomyiidae.Research supported by National Research Council of Canada, Operating Grant Nos. A3881 and A3706, and Cooperative Grant No. A0243: Nature Products Chemistry and Chemical Ecology of Canadian Insect and Disease Pests.     

Headspace Analysis in Chemical Ecology: Effects of Different Sampling Methods on Ratios of Volatile Compounds Present in Headspace Samples

The effects that different headspace sampling methods have on the analysis of the ratios of compounds present in the headspace of a synthetic mixture and a biological sample were evaluated using the following methods: solid-phase microextraction (SPME), a syringe, and the porous polymers Porapak Q, Tenax TA, and Hayesep Q (thermal and solvent desorption). The performance of each method was only evaluated for a certain sampling period and under given experimental conditions. The test mixture comprised pentan-3-ol, 4-penten-1-ol, (E)-2-hexenal, hexan-1-ol, heptanal, (1S,5S)-(–)--pinene, 6-methyl-5-hepten-2-one, hexyl acetate, (R)-(+)-limonene, and undecane. SPME gave significantly different ratios of pentan-3-ol, 4-penten-l-ol, hexan-1-ol, heptanal, (1S,5S)-(–)--pinene, 6-methyl-5-hepten-2-one, hexyl acetate, limonene, and undecane compared with the other methods. No significant differences were observed between the syringe and the porous polymers or between the three different porous polymers used. The method of release of the trapped analytes from the polymers, thermal or solvent desorption, did not affect the ratios of compounds. The effects that different sampling methods have on the ratios of compounds present in the headspace of a biological sample, ripe banana, were evaluated. The headspace was sampled using SPME and the porous polymers Porapak Q and Tenax TA (thermal desorption). The following compounds were identified in the headspace of ripe bananas: 2-methylbutyl acetate, pentyl acetate, 2-methylbutyl propanoate, butyl butanoate, and pentyl butanoate. SPME gave significantly different ratios of 2-methylbutyl acetate, pentyl acetate, butyl butanoate, and pentyl butanoate when compared to Porapak Q and Tenax TA. No significant differences on the ratios of compounds present in the headspace of ripe banana were observed when the two polymers were compared. The use of different sampling methods in headspace analysis of biological samples is dicussed.