On-line CO, CO2 emissions evaluation and (benzene, toluene, xylene) determination from experimental burn of tropical biomass

Atmospheric pollution and global warming issues are increasingly becoming major environmental concerns. Fire is one of the significant sources of pollutant gases released into the atmosphere; and tropical biomass fires, which are of particular interest in this study, contribute greatly to the global budget of CO and CO₂. This pioneer research simulates the natural biomass burning strategy in Malaysia using an experimental burning facility. The investigation was conducted on the emissions (CO₂, CO, and Benzene, Toluene, Ethylbenzene, Xylenes (BTEX)) from ten tropical biomass species. The selected species represent the major tropical forests that are frequently subjected to dry forest fire incidents. An experimental burning facility equipped with an on-line gas analyzer was employed to determine the burning emissions. The major emission factors were found to vary among the species, and the specific results were as follows. The moisture content of a particular biomass greatly influenced its emission pattern. The smoke analysis results revealed the existence of BTEX, which were sampled from a combustion chamber by enrichment traps aided with a universal gas sampler. The BTEX were determined by organic solvent extraction followed by GC/MS quantification, the results of which suggested that the biomass burning emission factor contributed significant amounts of benzene, toluene, and m,p-xylene. The modified combustion efficiency (MCE) changed in response to changes in the sample moisture content. Therefore, this study concluded that the emission of some pollutants mainly depends on the burning phase and sample moisture content of the biomass.     

五氟苄基羟胺衍生与GC/MS联用分析大气中的单羰基化合物和多羰基化合物

利用涂布五氟苄基羟胺（PFBHA）的Tenax-TA作为固体吸附剂,采取主动采样的方式采集大气中羰基化合物,再经溶剂洗脱和氮吹浓缩后用气相色谱/质谱（GC/MS）分析,成功检测到14种单羰基化合物和2种二羰基化合物（乙二醛与甲基乙二醛）.研究表明：在吸附剂的装载量为50mg的前提下,当衍生剂的涂布量为260nmol,采集流速为50mL·min^-1时,采集效果最佳.羰基化合物的检测限、平行样的相对标准偏差和样品的加标回收率范围分别为0.54～3.83ng·m^-3、1.0%～14.2%、89.2%～113.8%.该方法在实际大气样品中合适的采样时间为0.5～8.0h.利用此法对上海市宝山区大气中羰基化合物进行了检测,成功检测到16种羰基化合物,且具有明显的日变化趋势.     

Determination of Acaricide Residues in Saudi Arabian Honey and Beeswax Using Solid Phase Extraction and Gas Chromatography

Determination of acaricide residues of flumethrin, tau-fluvalinate, coumaphos, and amitraz in honey and beeswax was carried out using a rapid extraction method utilizing C-18 SPE cartridges and an analytical method utilizing GC with ECD, NPD, and MSD detectors for the four acaricides. Recovery percentages from the extraction method ranged from 90–102%, while the minimum detection levels ranged from 0.01–0.05 mg/kg for the acaricides. Nine of the 21 analyzed samples were found to be contaminated with the acaricides tau-fluvalinate and coumaphos. Neither flumethrin nor amitraz was detected in any of the honey or wax samples. Coumaphos was found only in honey samples in which two samples exceeded the tolerance levels set by EPA and EC regulations. It has not been detected in beeswax. Five honey samples and eight beeswax samples were found to be contaminated with tau-fluvalinate. One of the wax samples was contaminated with a relatively high residue of tau-fluvalinate and contained above 10 mg/kg.     

CuMnOx／γ-Al2O3及稀土助剂对VOCs催化燃烧性能的影响

利用浸渍法制备了Cu—Mn复合氧化物催化剂和加入不同稀土含量的Cu—Mn复合氧化物催化剂,通过实验优选出加入稀土催化剂中稀土含量的最优配比,以气相色谱为检测手段,考察了加入稀土和不加稀土催化剂的催化燃烧性能,结果表明,加入稀土的催化剂T99（催化处理效率达到99％时的温度）比不加稀土的催化剂降低30～40℃,具有更好的低温活性,且对多种VOCs均能降低反应温度。     

吹扫捕集-GC/MS法测定饮用水中致嗅物质

采用吹扫捕集-气相色谱/质谱联用法测定饮用水中6种致嗅物质,优化了吹扫捕集条件。方法线性良好,甲硫醚、二甲二硫、甲苯、异佛尔酮、癸醛、β-环柠檬醛的检出限分别为10.5μg/L、0.558μg/L、0.862μg/L、47.4μg/L、4.75μg/L、3.77μg/L,标准溶液平行测定的RSD≤10.9%,加标回收率为71.0%～125%。     

气相色谱法测定工作场所空气中多苯类、多环芳烃类、不饱和脂肪族酯类化合物

建立了同时测定工作场所空气中多苯类、多环芳烃类、不饱和脂肪族酯类化合物的检测方法,该方法操作简便,重复性好,在目标化合物质量浓度2~100 mg/L范围内线性良好,回收率90%,RSD5%,检出限为0.4~0.6 mg/L。结果表明,方法适用于工作场所空气中多苯类、多环芳烃类、不饱和脂肪族酯类化合物的检测要求。     

气相色谱/质谱法测定水中五氯酚

用GC/MS法测定环境水体和废水中的五氯酚 ,选择乙酸酐作衍生化试剂 ,二氯甲烷为萃取剂 ,比较了不同的衍生pH条件 ,以m/z为 2 6 6的定量特征离子定量 ,获得了较高的灵敏度和选择性     

吹脱捕集GC/FID法测定海河水中挥发性有机物

采用吹脱捕集GC/FID法对海河干流水中挥发性有机物进行定性、定量分析。共检测出 39种挥发性有机物 ,不同化合物的回收率为 84 2 %～ 143 2 % ,相对偏差为 1 5 %～ 9 6 %。当水样体积为 2 5mL时 ,方法检测限为 0 0 0 1μg/L～ 0 4μg/L。     

吹扫捕集-气相色谱质谱法测定地表水中12种氯苯类有机物

采用吹扫捕集-气相色谱质谱联用法测定地表水中的12种氯苯类有机污染物,特别是一些半挥发性的多氯苯化合物如五氯苯、六氯苯等。在室温下分析时,当进样体积为25.0 mL,吹扫时间为11 min,解析时间为3 min,采用全扫描方式定量分析时,方法检出限为0.02~1.50μg/L。不同浓度水平的加标回收率为86.0%~113%,相对标准偏差为1.3%~17.5%;实际样品加标回收率为84.4%~119%,相对标准偏差为2.2%~18.9%。该法具有简便高效、灵敏度高、有机溶剂用量少等优点,适用于饮用水和地表水中氯苯类化合物的测定,并为突发性环境污染事件氯苯类有机物的快速响应提供了一种快速有效的检测方法。     

便携式GC-MS在应急监测中的应用

建立了便携式GC-MS测定空气和水体中挥发性有机物(VOCs)的方法,能快速、有效地对空气中37种和水体中54种挥发性有机物进行现场定性和定量。具有相关性好、检出限低、精密度好、准确度高的特点,适用于空气和水体中挥发性有机物的应急监测工作。