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501.
Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were analysed in surface soil samples collected in 2001–2002 at an open urban area of Madrid. In order to obtain representative samples, three collection points at the site were chosen. The most abundant PAHs and PCBs were phenanthrene, fluorene, pyrene, chrysene and benzo[a]pyrene and hexa- and heptachlorinated PCBs, respectively. The sum of selected PAHs (13 compounds) and PCBs (15 congeners) averaged 1 and 0.1?µg?g?1, respectively. PCB levels in winter were 2–10 times higher than summer ones, while seasonal variation for most of PAHs were not observed. Good correlations among all PCBs were found. Five PAHs were also well correlated. 相似文献
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503.
Cellulose/polyethylene (CPE) mixture 3:1, w/w with and without three clay catalysts (K10 – montmorillonite K10, KSF – montmorillonite KSF, B – Bentonite) addition were subjected to pyrolysis at temperatures 400, 450 and 500 °C with heating rate of 100 °C/s to produce bio-oil with high yield. The pyrolytic oil yield was in the range of 41.3–79.5 wt% depending on the temperature, the type and the amount of catalyst. The non-catalytic fast pyrolysis at 500 °C gives the highest yield of bio-oil (79.5 wt%). The higher temperature of catalytic pyrolysis of cellulose/polyethylene mixture the higher yield of bio-oil is. Contrarily, increasing amount of montmorillonite results in significant, almost linear decrease in bio-oil yield followed by a significant increase of gas yield. The addition of clay catalysts to CPE mixture has a various influence on the distribution of bio-oil components. The addition of montmorillonite K10 to cellulose/polyethylene mixture promotes the deepest conversion of polyethylene and cellulose. Additionally, more saturated than unsaturated hydrocarbons are present in resultant bio-oils. The proportion of liquid hydrocarbons is the highest when a montmorillonite K10 is acting as a catalyst. 相似文献
504.
本研究针对大气中挥发性有机物(VOCs)浓度低,难于分析等特点,以Carboxen 1000作为吸附剂,制作一种新型动态针捕集阱(needle trap)装置,可用于主动富集大气中低浓度VOCs.该装置与气相色谱-质谱(GC-MS)联用,操作简单、无需溶剂、容易定性定量.选择空气中苯系物(BTEX)为目标化合物,对needle trap装置从设计原理到实际应用进行了详细分析,将萃取条件与穿透体积等实验条件进行优化,建立了needle trap吸附提取空气中BTEX的最佳条件.结果表明,方法检出限低至0.05ng·mL-1,加标回收率为86.5%~110.5%,符合外场采样要求. 相似文献
505.
The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds include alkanes, cyclic hydrocarbons, alkenes, aromatics, acids, alcohols, aldehydes, ketones, esters, halocarbons and so on. The numbers of VPOs found are 118 in Beijing, 83 in Lang-fang and 65 in Tianjin in the winter, and 56, 39 and 72 in the summer respectively. Based on the data of some representative compounds determined quantitatively by GC and GC/MS, a profile of organic pollution in the air of the three cities is presented. 相似文献
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采用GC/MS联用仪对焦化、染料废水和地表水中有机物进行定性、定量分析,探讨了污染源与受纳区的地表水中有机物种类和含量间的关系。 相似文献
510.
运用热脱附/GC/MS分析研究室内空气中TVOC浓度及种类分布 总被引:4,自引:0,他引:4
利用热脱附/GC/MS联用技术定性、定量(半定量)分析了多组有代表性的室内空气样品。结果表明,室内空气挥发性有机气体的主要成分是苯系物、烃类、醛酮类、酯类等;装修后3个月内的家居室内空气中的苯25%超标,甲苯58%超标,二甲苯79%超标,TVOC 100%超标;一年后,仅TVOC还有11%的超标。办公室情况类似。 相似文献