气相色谱-质谱联用法测定土壤中16种多环芳烃

应用加速溶剂萃取气相色谱-质谱联用法测定土壤中16种多环芳烃。确定了二氯甲烷-丙酮(体积比1:1)作为提取溶剂,方法检出限为0.10～3.90ng/g,加标回收率为72.6%～123.5%。方法检出限较低,精密度好,适用于土壤样品中多环芳烃的分析。     

Ultrasonic wave extraction and simultaneous analysis of polycyclic aromatic hydrocarbons (PAHs) and phthalic esters in soil

A method is developed for detection of polycyclic aromatic hydrocarbons(PAHs) and Phthalic Acid Esters(PAEs) in soil samples. Ultrasonic Wave Extraction under airtight circumstances is adopted to extract the analytes in soil samples with n-hexane–acetone(V:V=1:1) as extraction solvent. This method has several advantages, including high extraction efficiency, short time, convenience and simplicity. It can be used to detect polycyclic aromatic hydrocarbons(PAHs) and Phthalic Acid Esters(PAEs) in soil.     

荧光-紫外检测器高效液相色谱法检测地下水中16种多环芳烃

应用荧光-紫外检测器联用的高效液相色谱法分析地下水中16种多环芳烃。对高效液相色谱条件进行优化,建立了分析方法,并用于实际水样分析。在较佳的实验条件下,加标回收率为86.3%～105%,方法精密度(RSD,n=7)为0.39%～2.55%,检出限为0.001～0.010μg/L。分析16种PAHs仅用20min,比EPA8310方法中采用的液相色谱法缩短了17min。方法灵简便、准确,灵敏度高,分析时间短,适用于大批量地下水中痕量多环芳烃的分析。     

Determination of fuel combustion product in airport runoff water samples using liquid–liquid extraction with gas chromatography–spectrometry

Determination of xenobiotics in samples of airport runoff water is both a complex and indispensable task due to an increasing threat resulting from the activities of numerous airports. The aim of this study was to develop, optimize, and validate a procedure based on liquid–liquid extraction (LLE) coupled with gas chromatography–mass spectrometry (GC–MS) for the determination of polycyclic aromatic hydrocarbons (PAHs). So far, no procedure was available that would ensure reliable data about concentration levels of these toxic pollutants in a new type of environmental samples, such as airport stormwater. The most difficult step in the analytical procedure used for the determination of fuel combustion products in airport stormwater samples is sample preparation. In this work, eight different protocols of sample preparation were tested. The evaluation of the LLE demonstrated that the best extraction conditions were as follows: dichloromethane (extraction solvent), solvent volume of 15 mL and sample volume of 250 mL. The percent recovery values ranged from 66 to 106 %, which shows that the LLE technique is a powerful method for extracting PAHs from airport runoff water samples with a complex matrix composition. Moreover, the developed procedure was characterized by satisfactory selectivity and a relatively low LOQ (0.17–0.52 μg/L). The procedure has been successfully applied to the analysis of stormwater samples collected from different sites at international airport in Poland. The procedure can thus be used as a tool for tracking the environmental fate of these compounds and for assessing the environmental effect of airports.     

气相色谱-质谱法同时测定河流沉积物中多环芳烃和有机氯农药

建立了用加速溶剂萃取,气相色谱-质谱法同时测定河流沉积物中16种多环芳烃和19种有机氯农药的分析方法,优化了萃取溶剂、萃取温度和时间、凝胶渗透色谱收集时间、固相萃取洗脱溶剂和洗脱体积等条件。16种多环芳烃的方法检出限在0.15~0.59 ng/g,加标回收率为82%~102%,相对标准偏差(RSD,n=5)为1.1%~4.5%。19种有机氯农药的方法检出限在0.14~2.23 ng/g,加标回收率为71%~108%,相对标准偏差(RSD,n=5)为1.0%~4.5%。实际样品的测定结果表明,该方法分离效果较好,能够满足沉积物样品中多环芳烃和有机氯农药的分析要求。     

Solvent–water extraction method for the evaluation of polycyclic aromatic hydrocarbons bioavailability in coal–tar-contaminated soils

A solvent–water extraction method was proposed as an assessment tool to estimate the bioavailability of polycyclic aromatic hydrocarbons in coal–tar-contaminated soils. The approach taken was to measure the percent of polycyclic aromatic hydrocarbons extracted by a solvent–water mixture and comparing the results with the percent of polycyclic aromatic hydrocarbons degraded in a soil slurry reactor. Five soil samples from three former manufactured gas plant sites and a coal–tar disposal site which were operated between 1880 and 1947, and 1945 and 1950, respectively, in Iowa, USA were used in this study. Extraction experiments were conducted using acetone–water or ethanol–water mixtures with solvent volume fractions ranging from 1.0 to 0.4 (v/v). The percent of polycyclic aromatic hydrocarbons extracted from the various soils decreased as the volume fraction of the solvent in the solvent–water mixture was reduced. An acetone–water mixture of 0.6 was found to be appropriate in correlating the percent of polycyclic aromatic hydrocarbons degraded to the percent of polycyclic aromatic hydrocarbons extracted. For the first correlation, the percent extracted and the percent biodegraded were modified by using the molecular weights and log K _ow of polycyclic aromatic hydrocarbons, respectively. For the second correlation, the equation relating the percent extracted and the percent biodegraded was modified using soil properties such as organic carbon content and percent of clay and silt. Although the experiments were conducted for a limited number of soils, the extraction method appeared to be a good starting point in estimating the bioavailability of polycyclic aromatic hydrocarbons in coal–tar-contaminated soils.     

快速溶剂萃取(S-916)/GC-MS法测定土壤中15种多环芳烃

本文建立了S-916快速溶剂萃取仪(Buchi瑞士)快速萃取-气相色谱-质谱仪(GC-MS)联用测定土壤中15种多环芳烃(PAHs)含量的方法。土壤样品经正己烷、丙酮快速溶剂萃取,除水浓缩后,利用硅酸镁小柱进行净化,直接进GC-MS测定。结果表明,在5.01000.0μg/L浓度范围内,15种PAHs的相关系数均在0.996以上,RF RSD<12%,加标回收率在80%117%之间,15种PAHs的最低检出限均低于0.40μg·kg^-1.该方法灵敏、快速、准确可靠,完全满足实验室对土壤中PAHs的检测要求,可为土壤中多环芳烃(PAHs)的污染情况提供快速检测依据。     

Bioremediation of heavily hydrocarbon-contaminated drilling wastes by composting

Oil-based drilling cuttings comprise a large and hazardous waste stream generated by oil and gas wells drilling operations. Oil-based cuttings are muddy materials with high contents of salts and hydrocarbons. Composting strategies have shown to be effective in the biodegradation of petroleum hydrocarbons, and it offers numerous advantages in comparison with other bioremediation methods. In order to assess the effectiveness of drilling cuttings bioremediation by composting with food and garden wastes, an experiment was conducted in 60-L reactors for 151 days. Four treatments were carried out: only oil-based cuttings, two proportions (in a volume basis) of organic wastes to drilling cuttings (33 and 75 %) and only organic wastes (as a traditional composting reference), with pine-tree woodchips as bulking agent. High degradation percentages of total hydrocarbons (≈82 %), n-alkanes (≈96 %) and the 16 USEPA-listed polycyclic aromatic hydrocarbons (≈93 %) were reached in the treatment with 75 % of organic wastes, and applying 33 % of organic wastes was not more effective than not applying organic wastes for the drilling cuttings hydrocarbons biodegradation. Furthermore, in the treatment with 75 % of organic wastes, alkanes half-life and polycyclic aromatic hydrocarbons half-life were about 10 times and four times lower, respectively, than those in the treatment with 33 % of organic wastes. Possibly, lower hydrocarbons and salts initial concentrations (i.e., lower toxicity), higher microbial counts, adequate nutrient proportions and water content supported a high biological activity with a consequent elevated biodegradation rate in the treatment with 75 % of organic wastes.     

Biodegradation of polycyclic aromatic hydrocarbon by a halotolerant bacterial consortium isolated from marine environment

The biodegradability of polycyclic aromatic hydrocarbons such as naphthalene, fluorene, anthracene and phenanthrene by a halotolerant bacterial consortium isolated from marine environment was investigated. The polycyclic aromatic hydrocarbons degrading bacterial consortium was enriched from mixture saline water samples collected from Chennai (Port of Chennai, salt pan), India. The consortium potently degraded polycyclic aromatic hydrocarbons (> 95%) at 30g/L of sodium chloride concentration in 4 days. The consortium was able to degrade 39 to 45% of different polycyclic hydrocarbons at 60 g/L NaCl concentration. Due to increase in salinity, the percent degradation decreased. To enhance polycyclic aromatic hydrocarbons degradation, yeast extract was added as an additional substrate at 60g/L NaCl concentration. After the addition of yeast extract, the consortium degraded > 74 % of polycyclic aromatic hydrocarbons at 60 g/L NaCl concentration in 4 days. The consortium was also able to degrade PAHs at different concentrations (5, 10, 20, 50 and 100 ppm) with 30 g/L of NaCl concentration. The polycyclic aromatic hydrocarbons degrading halotolerant bacterial consortium consists of three bacterial strains, namely Ochrobactrum sp., Enterobacter cloacae and Stenotrophomonas maltophilia.     

Sample preparation for analyzing polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment by gas chromatography/mass spectrometry

A sample preparation technique was developed to isolate and separate two classes of combustion-produced pollutants: three- to six-ring polycyclic aromatic hydrocarbons (PAH) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), from sediment samples for interference-free analyses by gas chromatography/mass spectrometry (GC/MS). The method involves soxhlet extraction with methylene chloride, sulfur removal with activated copper powder, gel filtration chromatography with Sephadex LH-20, polarity separations of PAH and PCDD/F with prepacked silica gel solid-phase extraction columns, and isolation of PCDD/F from polychlorinated biphenyls with microalumina columns. Stringent procedural controls were established to achieve clean isolations and recoveries of 70% or better for each step in the method. The prepared sample extracts were analyzed by capillary GC and GC/MS. Electron impact ionization was used for PAH, and negative chemical ionization with methane as a reagent gas was used for PCDD/F. Reproducible results were obtained. The method is simple and has the advantage of conserving sample consumption since two classes of compounds can be analyzed from the same sample. This can be critical in sediment core analyses where sample size is usually limited.     

过硫酸钠修复土壤中多环芳烃的准确测定

多环芳烃(PAHs)是一类具有致癌、致突变、致畸的碳氢化合物,具有较高的辛醇-水分配系数,易被土壤颗粒吸附而影响环境和人体健康。过硫酸钠(Na₂S₂O₈)氧化法是近些年来国内外修复PAHs污染土壤较为常用的方法,但现阶段在测定修复后土壤中PAHs含量、进行土壤修复效果评估时亟待解决的问题是：经该方法修复的土壤,若土壤中残留有过硫酸钠,在样品前处理过程中由于提取温度较高,可能会进一步加速多环芳烃的氧化反应,从而影响土壤中PAHs的准确测定。本文建立了一种在修复后土壤中加入还原剂抗坏血酸,与残留的过硫酸钠反应生成脱氢抗坏血酸,采用索氏提取结合气相色谱-质谱法(GC-MS)同时测定土壤中16种PAHs的方法,PAHs加标回收率为76.2%～110.0%。而修复后土壤若不加还原剂直接进行索氏提取,用GC-MS测定,可能会使部分PAHs及替代物的测定不准确,PAHs加标回收率仅为6.0%～72.4%。通过对比分析表明,在样品提取前加入还原剂,可以有效地消除残留过硫酸钠的影响,提高测定修复后土壤中PAHs含量的准确性。     

Development of a thermal desorption method for the analysis of particle associated polycyclic aromatic hydrocarbons in ambient air

An investigation for the analysis of polycyclic aromatic hydrocarbons in airborne particulates using thermal desorption and gas chromatography-mass spectrometry is described. Samples are obtained from ambient air using fibreglass filters and the volatile material from the filter is thermally desorbed to gas chromatograph. A 30 meter capillary column is used to separate the hydrocarbons and eight polyaromatic hydrocarbons are used to test the method and recovery is >95%. The eight polycyclic aromatic hydrocarbons anthracene, phenanthrene, fluoranthrene, pyrene, benzo (a) anthracene, chrysene, benzo (a) pyrene and benzo (e) pyrene were the most abundant PAHs found in the samples of ambient air with current method at Uxbridge-London. Application of the measurement of polycyclic aromatic hydrocarbons in ambient air samples shows that the hydrocarbons trapped in the particle phase to a lesser degree at higher ambient temperature. In conclusion a method has been developed to transfer the PAHs in particle phase from a filter to GC-MS by thermal desorption. A standard mixture of PAHs, when absorbed onto the filter, did lead to strong analyte absorbent interactions by the high percent recovery of the sample.     

Distribution behavior of polycyclic aromatic hydrocarbons in roadside soil at traffic intercepts within developing cities

A study of polycyclic aromatic hydrocarbons pollution in roadside soil was conducted in developing city environment of northern India during autumn and winter season to ascertain the contamination levels and their distribution behavior in soil. The concentration of polycyclic aromatic hydrocarbons was determined at ten locations of Jalandhar city, Punjab in India at 1, 2 and 3 m distances from roadside in soil covering all the major traffic intercepts within city. The samples were extracted in acetone and dichloromethane (1:1) using soxhlet extraction. The extracts were then filtered on a silica gel micro column to remove impurities and elute was subjected to GC-FID. The total average concentration (city average) was found to be 4.04 ?g/g and 16.38 ?g/g during winter and autumn respectively. DiBenzo (ah) Anthracene and Benzo (a) Pyrene were the individual polycyclic aromatic hydrocarbons found in highest concentration at all the intercepts ranging between 0.008 to 28.4 ?g/g during winter and 0.01 to 252.55 ?g/g during autumn. Average concentration of non-carcinogenic and carcinogenic polycyclic aromatic hydrocarbons during winter and autumn was found to be 2.1 and 6.4 and 4.74 and 35.08 ?g/g respectively. The average ratio of non-carcinogenic and carcinogenic Polycyclic Aromatic Hydrocarbons was found to be 1:3 during winter, and 1:7.6 during autumn at most of the intercepts. Total carcinogenic polycyclic aromatic hydrocarbons concentration was found quite high (80 %) in comparison to non-carcinogenic polycyclic aromatic hydrocarbons (20 %) at most of the intercepts.     

Levels of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in sediment of bitumen deposit impacted area

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls were investigated in sediment of bitumen deposit impacted area of Agbabu, Nigeria, to determine the present level of contamination with these toxic compounds prior to exploitation. Samples were collected during the dry season (March) and the wet season (August) of year 2008. Analysis was carried out with gas chromatography using mass spectrometry detector for polycyclic aromatic hydrocarbons and flame ionization detector for polychlorinated biphenyls. In the dry season sum of concentration of PAHs ranged from zero to 0.12 ± 0.06 ppm, while in the wet season the minimum was 0.18 ± 0.07 ppm and the maximum was 1.04 ± 0.16 ppm. Most of these values were higher than sum of polycyclic aromatic hydrocarbons concentrations of 1–10 μg/kg indicating that they were likely to come from anthropogenic sources. Average concentrations of PAHs such as naphthalene and benzo (a) pyrene obtained in sediment in the wet season in some of the stations were higher than recommended limits. The linear regression analysis between sum of concentrations and percentage organic carbon showed no significant correlation in sediment in the dry season (r² = 0.0025) and in the wet season (r² = 0.1345). The predominance of 4–6 ringed polycyclic aromatic hydrocarbons and the ratios between pairs of individual polycyclic aromatic hydrocarbons showed that they are likely to have come from pyrolytic sources. No polychlorinated biphenyl congener was detected in the samples.     

海洋沉积物中多氯联苯、多环芳烃和有机氯农药的同时净化与分离

研究了海洋沉积物提取液中28种多氯联苯(PCBs)、16种多环芳烃(PAHs)和21种有机氯农药(OCPs)在硅胶-氧化铝复合净化柱上的同时净化与分离效果,结果表明:在充填4 cm3%去活化氧化铝-6 cm 3%去活化硅胶的8 mm i.d×15 cm固相萃取净化柱上,使用10 mL正己烷作为淋洗PCBs的分割点,可实现PCBs、PAHs和OCPs的满意分离,更有利于PCBs与高环数PAHs、极性较强OCPs的分离。继续用20 mL正己烷-二氯甲烷混合液(体积比1∶1)洗脱,28 PCBs、16种PAHs和21种OCPs均可获得有效回收,回收率分别为75%~110%、76%~115%、75%~130%。经海洋沉积物标准参考物质验证,该方法实用、可靠,流程简单,试剂消耗少,成本低,适用于海洋环境地质调查中基质复杂沉积物样品的定量分析。     

固体模拟样品中多环芳烃有机污染物提取方法研究

对有机污染物分析的样品前处理技术——超临界萃取、微波萃取、超声提取和索氏提取进行了对比研究。结合气相色谱质谱测定技术比较了4种方法对模拟样品中16种多环芳烃化合物的提取效果。探讨了温度、改进剂对超临界萃取的影响，无改进剂的纯C02流体对16种多环芳烃的低沸点化合物萃取回收率可达80％，对高沸点化合物应在加入改进剂的基础上提高萃取温度。与超临界萃取相比，微波萃取在对高沸点化合物的萃取上具有优势。     

Molecular characterization of phenanthrene-degrading methanogenic communities in leachate-contaminated aquifer sediment

The existence of polycyclic aromatic hydrocarbons in the various environments has aroused great environmental concerns due to their potential hazards to human health. The presence of polycyclic aromatic hydrocarbons in aquifer is particularly sensitive where groundwater is used as a source of potable water. Anaerobic biodegradation of polycyclic aromatic hydrocarbons is an attractive option for remediation of contaminated aquifer sediment. Bacterial and archaeal community structures of phenanthrene-degrading aquifer sediment under methanogenic condition were investigated using clone library analysis in combination with microcosm study. The bacterial members were all affiliated with ??-Proteobacteria. Phylum Euryarchaeota was the predominant archaeal group, represented by genera Methanosarcina, Methanobacterium and Thermogymnomonas. Both bacteria (genera Citrobacter and Pseudomonas) and archaea (genus Methanosarcina) might have links to phenanthrene degradation process. This work might provide some new insights into developing strategies for the isolation of the putative polycyclic aromatic hydrocarbons degraders under methanogenic condition and bioremediating polycyclic aromatic hydrocarbons in leachate-contaminated aquifer sediment.     

Carbon isotope systematics of individual hydrocarbons in hydrothermal petroleum from Escanaba Trough, northeastern Pacific Ocean

We submitted individual aliphatic and polycyclic aromatic hydrocarbons in samples of hydrothermal petroleum from Escanaba Trough to compound specific isotope analysis to trace their origins. The carbon isotope compositions of the alkanes and polycyclic aromatic hydrocarbons (means -27.5 and -24.7%, respectively) reflect a primarily terrestrial organic matter source.     

Enhanced Dissolved Organic Matter Recovery from Saltwater Samples with Electrodialysis

Complexities associated with dissolved organic matter (DOM) isolation from seawater have hampered compositional characterization of this key component of global carbon and nutrient cycles. DOM isolation efficiency by electrodialysis (ED) from salt-containing waters was optimized and evaluated on samples including coastal ocean seawater, open ocean seawater, artificial seawater from axenic cultures of marine phytoplankton, and artificial seawater samples containing standard compounds of different molecular sizes and charge. ED was performed with a system optimized for processing 2–10 L sample volumes. Additionally, the combination of ED and solid-phase extraction, using Bond Elut PPL exchange resin, was evaluated. Using only ED, the following DOC recoveries were achieved: coastal seawater, 71.3 ± 6.5 %; open ocean, 50.5 ± 3.1 %; phytoplankton cultures, 70.3 ± 12.5 %; glucose, 90.2 ± 2.1 %; EDTA, 67.5 ± 9.9 %; and vitamin B₁₂, 98.3 ± 1.6 %. With the combination of PPL and ED techniques, an average DOC recovery of 76.7 ± 2.6 % was obtained for coastal seawater, but this recovery was not statistically different from seawater recoveries using only ED. Comparison of C/N ratios and fluorescence excitation emission matrices taken at the beginning and end of the recovery process for coastal samples processed using only ED indicated that the final recovered material was representative of the DOM present in the original samples. Typical recoveries using combined PPL and ED exceed those of previous isolation methods.     

拉萨市拉鲁湿地多环芳烃污染及其来源

通过分析采集的土壤、沉积物和大气样品,对拉萨郊区的拉鲁湿地多环芳烃污染及其来源进行了初步研究.湿地表层土壤中16种多环芳烃的平均含量的总含量为82.45×10^-9,既存在低环数的多环芳烃,又含有高环数的多环芳烃;湿地土壤中的多环芳烃主要来自于大气.