Volatile Organic Compounds: Sampling Methods and Their Worldwide Profile in Ambient Air

The atmosphere is a particularly difficult analytical system because of the very low levels of substances to be analysed, sharp variations in pollutant levels with time and location, differences in wind, temperature and humidity. This makes the selection of an efficient sampling technique for air analysis a key step to reliable results. Generally, methods for volatile organic compounds sampling include collection of the whole air or preconcentration of samples on adsorbents. All the methods vary from each other according to the sampling technique, type of sorbent, method of extraction and identification technique. In this review paper we discuss various important aspects for sampling of volatile organic compounds by the widely used and advanced sampling methods. Characteristics of various adsorbents used for VOCs sampling are also described. Furthermore, this paper makes an effort to comprehensively review the concentration levels of volatile organic compounds along with the methodology used for analysis, in major cities of the world.     

遂宁市夏季大气挥发性有机物污染特征及来源解析

2019年7-8月在四川省遂宁市实验学校、遂宁中学、金鱼小学、石溪浩4个点位同步开展为期20d的挥发性有机物(VOCs)离线观测,分析了遂宁市VOCs浓度时空分布特征、臭氧生成潜势(OFP)和VOCs主要来源。遂宁市TVOC体积浓度为39.4×10^-9,占比较高的组分为OVOCs和烷烃,体积浓度分别为15.6×10^-9和13.3×10^-9,占比分别为39.5%和33.6%。遂宁中学、金鱼小学、石溪浩24 h平均体积浓度分别为29.8 ×10^-9、58.4 ×10^-9、30.0×10^-9;加密点实验学校的小时平均浓度为22.9×10^-9。遂宁市总OFP为166.7 μg/m³,占比最大的为烯烃(33.1%)。实验学校、遂宁中学、金鱼小学、石溪浩OFP浓度分别为101.2、134.4、243.6、122.1 μg/m³。金鱼小学采样点位于工业园区下风向,受工业园区企业排放源影响,VOCs浓度和OFP值均明显高于其他点位。PMF模型源解析结果表明:遂宁市VOCs来源占比最大的为工业排放源,达32%;其次为机动车尾气源、燃烧源,占比均达17%;油气挥发源、天然源、溶剂使用源分别占13%、11%、10%。工业源、机动车尾气来源占比最高的均是金鱼小学,分别为39%、30%;天然源占比较高的是实验学校(13%)和石溪浩(10%)。     

石家庄大气中优先控制挥发性有机物筛选

综合考虑国内外优先控制污染物筛选的方法,结合实际调查情况,制定了石家庄市大气中优先控制挥发性有机物筛选的原则。对检出率高、贡献率高,可能对人体健康存在潜在危害性的挥发性有机物作筛选,提出了包含20种化合物的优先控制名单,其中卤代烃7种,芳香烃5种,酯类3种,酮类2种,烯烃、醛类和硫化物各1种。从化合物的用途和应用领域分析,医药化工行业可能是石家庄市区大气中挥发性有机物的主要排放源。     

兰州市城区夏季大气挥发性有机物污染特征及来源解析

2020年7月对兰州市城区大气挥发性有机物进行连续24 h测定,研究其污染特征和臭氧生成潜势等,并进行来源解析。结果表明:兰州超级站点 VOCs的平均质量浓度为99.59 μg/m³,各类挥发性有机物中烷烃占比最大,占总挥发性有机物浓度的33.81%;对挥发性有机物进行臭氧生成潜势分析,排名靠前的物种为甲苯、乙烯、乙酸乙烯酯;利用PMF模型对挥发性有机物进行源解析,结果显示VOCs来源贡献为机动车源(31.30%)、油气挥发或泄漏(24.10%)、溶剂使用源(18.60%)、燃烧和化工工艺源(17.20%)、天然源(8.80%)。建议将控制机动车排放、油气挥发和泄漏、溶剂使用等作为消减城市大气挥发性有机物和臭氧污染的重点。     

机动车排放尾气中挥发性有机污染物对环境空气质量影响初探

采用气相色谱/质谱检测技术,对汽油和柴油、汽油车和柴油车排放气体以及天津市环境空气中主要挥发性有机污染物(VOCs)的组成种类及比例进行探析.结果表明,机动车排放的尾气中主要有机污染物为芳香烃类、烷烃类和烯烃类化合物,其中芳香烃类含量最高;汽油车排放的芳香烃类化合物浓度高于柴油车排放的浓度;机动车尾气对交通区域空气质量的影响高于工厂区(非化工区)、生活小区和公园.     

常州某农药生产场地土壤中挥发性有机物污染状况调查

对常州某农药生产场地土壤中挥发性有机物污染状况进行了调查。数据表明,该场地土壤中挥发性有机物污染以苯系物和卤代烃为主。苯系物浓度为0～56.7mg/kg,卤代烃浓度为0～1.14mg/kg,有潜在风险。     

绍兴市某工业区大气中挥发性有机物污染状况的研究

运用便携式气相色谱质谱仪,分析研究绍兴市某工业区大气中挥发性有机污染物的组成及污染状况,主要污染物的平均浓度范围在18.9~348μg/m³之间,初步掌握工业区内挥发性有机污染物的来源,为今后大气污染事故的应急处理和预防,提供信息支持与技术保障。     

空气中挥发性有机物污染状况及健康风险评价

为了了解南京某县空气中挥发性有机污染物(VOCs)的污染状况,采用苏码罐采样-气相色谱-质谱法分析了该县不同功能区空气中的VOCs,探讨了其可能来源并采用国际公认的评价模型,对空气中的VOCs进行了健康风险评价。     

Spatial Analysis of Volatile Organic Compounds from a Community-Based Air Toxics Monitoring Network in Deer Park,Texas, USA

In the summer of 2003, ambient air concentrations of volatile organic compounds (VOCs) were measured at 12 sites within a 3-km radius in Deer Park, Texas near Houston. The purpose of the study was to assess local spatial influence of traffic and other urban sources and was part of a larger investigation of VOC spatial and temporal heterogeneity influences in selected areas of Houston. Seventy 2-h samples were collected using passive organic vapor monitors. Most measurements of 13 VOC species were greater than the method detection limits. Samplers were located at 10 residential sites, a regulatory air monitoring station, and a site located at the centroid of the census tract in which the regulatory station was located. For residential sites, sampler placement locations (e. g., covered porch vs. house eaves) had no effect on concentration with the exception of methyl tertiary-butyl ether (MTBE). Relatively high correlations (Pearson r > 0.8) were found between toluene, ethylbenzene, and o,m,p-xylenes suggesting petroleum-related influence. Chloroform was not correlated with these species or benzene (Pearson r < 0.35) suggesting a different source influence, possibly from process-related activities. As shown in other spatial studies, wind direction relative to source location had an effect on VOC concentrations.     

成都市人为源挥发性有机物排放清单及特征

基于成都市实地调查和环境统计等活动水平数据,采用排放因子法和计算模型等,编制了2014年成都市人为源VOCs排放清单,并完成了空间分配和不确定性分析。成都市人为源VOCs排放量为15.8×10~4t,其中化石燃料固定燃烧源、工艺过程源、溶剂使用源、移动源、储存运输源、其他源排放量分别为0.5×10~4、3.8×10~4、6.0×10~4、4.9×10~4、0.4×10~4、2.2×10~4t,溶剂使用源为最大人为排放源,其次是移动源和工艺过程源。木材加工业为最大工业贡献源,然后依次是医药制造业、非金属矿物制品业、化学原料、化学制品制造业、汽车制造业等。成都市人为源82%的VOCs排放量分布于二、三圈层的工业园区,而中心城区主要为移动源和建筑施工所贡献,其排放分布已随建成区联片发展而形成整体。排放清单活动水平数据可靠性较高,而排放因子存在一定不确定性。     

Organic Liquids Storage Tanks Volatile Organic Compounds (VOCS) Emissions Dispersion and Risk Assessment in Developing Countries: The Case of Dar-Es-Salaam City, Tanzania

The emission estimation of nine volatile organic compounds (VOCs) from eight organic liquids storage tanks companies in Dar-es-Salaam City Tanzania has been done by using US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total VOCs atmospheric emission has been established to be 853.20 metric tones/yr. It has been established further that petrol storage tanks contribute about 87% of total VOCs emitted, while tanks for other refined products and crude oil were emitting 10% and 3% of VOCs respectively. Of the eight sources (companies), the highest emission value from a single source was 233,222.94 kg/yr and the lowest single source emission value was 6881.87 kg/yr. The total VOCs emissions estimated for each of the eight sources were found to be higher than the standard level of 40,000 kg/yr per source for minor source according to US EPA except for two sources, which were emitting VOCs below the standard level. The annual emissions per single source for each of the VOCs were found to be below the US EPA emissions standard which is 2,000~kg/yr in all companies except the emission of hexane from company F1 which was slightly higher than the standard. The type of tanks used seems to significantly influence the emission rate. Vertical fixed roof tanks (VFRT) emit a lot more than externally floating roof tanks (EFRT) and internally floating roof tanks (IFRT). The use of IFRT and EFRT should be encouraged especially for storage of petrol which had highest atmospheric emission contribution. Model predicted atmospheric emissions are less than annual losses measured by companies in all the eight sources. It is possible that there are other routes for losses beside atmospheric emissions. It is therefore important that waste reduction efforts in these companies are directed not only to reducing atmospheric emissions, but also prevention of the spillage and leakage of stored liquid and curbing of the frequently reported illegal siphoning of stored products. Emission rates for benzene, toluene, and xylene were used as input to CALPUFF air dispersion model for the calculation of spatial downwind concentrations from area sources. By using global positioning system (GPS) and geographical information system (GIS) the spatial benzene concentration contributed by organic liquid storage tanks has been mapped for Dar-es-Salaam City. Highest concentrations for all the three toxic pollutants were observed at Kigamboni area, possibly because the area is located at the wind prevailing direction from the locations of the storage tanks. The model predicted concentrations downwind from the sources were below tolerable concentrations by WHO and US-OSHA. The highest 24 hrs averaging time benzene concentration was used for risk assessment in order to determine maximum carcinogenic risk amongst the population exposed at downwind. Established risk for adult and children at 2.9×10^-3 and 1.9×10^-3 respectively, are higher than the acceptable US-EPA risk of 1×10^-6. It is very likely that the actual VOCs concentrations in some urban areas in Tanzania including Dar-es-Salaam City are much higher than the levels reported in this study when other sources such as petrol stations and motor vehicles on the roads are considered. Tanzania Government therefore need to put in place: an air quality policy and legislation, establish air quality guidelines and acquire facilities which will enable the implementation of air quality monitoring and management programmes.     

重点行业企业用地地下水中挥发性有机物分析方法探究

通过优化顶空条件(氯化钠加入量、顶空平衡温度、顶空平衡时间),对采用顶空-气相色谱-质谱联用法测定地下水中55种挥发性有机物的方法进行探究.结果表明:该方法检出限为0.24～2.30μg/L,相对标准偏差为0.76％ ～13.2％,实际样品加标回收率为82.7％ ～119％.该方法具有较高的灵敏度、精密度和准确度,操作...     

南京市环境空气挥发性有机物监测方法比对研究

2018年9月20—29日,开展了南京市环境空气非甲烷烃(PAMS)原清单中57种挥发性有机物的手工和在线比对监测,监测项目主要包括碳氢化合物、卤代烃和含氧挥发性有机物。通过对VOCs 3 h均值、日均值和主要污染物指标等进行比对,分析在线监测数据与手工监测数据的相关性。测试结果表明,两种方法得到的3 h均值的差异度(1.43)和相关系数(0.897),日均值的差异度(2.16)和相关系数(0.946),呈现出差异度不显著、高度线性相关的特征。同时,进一步分析了监测数据产生偏离的原因,建议加强环境空气手工监测的质控管理,强化在线监测设备的运维管理,推进环境空气挥发性有机物监测的合理、有序发展。     

吹扫捕集-GC/MS-SIM法测定海水中挥发性有机污染物

采用吹扫捕集 -GC/MS -SIM法测定水中挥发性有机物 ,具有定量准确、操作简便等特点 ,检测限可达ng/L级 ,适合环境水中低浓度挥发性有机物的测定。测定实际海水样品 ,其浓度范围在 0 4ng/L～ 1 0 0 0ng/L之间。     

典型医化园区废气和环境空气中挥发性有机物污染特征

对典型医化园区中的挥发性有机物(VOCs)污染特征进行研究,采用便携式气相色谱质谱法监测园区及周边14个点位的环境空气,大气预浓缩气相色谱质谱法监测10个点位排气筒中废气。结果表明,废气中非甲烷总烃为1. 77～218 mg/m3,环境空气中甲苯、二氯甲烷、丙酮、乙酸乙酯、四氢呋喃的质量浓度分别为0. 048～0. 833,0. 022～3. 07,0. 011～0. 312,0. 004～0. 754和0. 004～0. 529 mg/m3;废气和环境空气中均检出含量较高的芳香烃、卤代烃、酯类、酮类等化合物,以及园区特征的氟苯类和噻吩类化合物。园区环境空气明显受到工业源VOCs污染,分布趋势为生产越密集区域VOCs值越高,经过园区后沿着风向逐渐降低,园区下风向11 km处可测到园区特征氟苯类物质。     

吹扫捕集-气相色谱质谱法分析土壤和沉积物中挥发性有机物

采用吹扫捕集-气相色谱质谱法对土壤和沉积物中挥发性有机物进行分析,优化了实验条件,所有物质的相对标准偏差小于5.0％,土壤样回收率在78.2％ ～99.8％之间,沉积物样的回收率在55.2％～95.2％之间.     

宁波市环境空气中VOCs污染状况及变化趋势分析

基于近7年来的连续监测数据,对宁波市环境空气中挥发性有机物(VOCs)的污染状况及变化趋势进行了初步分析。研究表明:在宁波市环境空气中检测出94种VOCs,其主要成分是饱和烷烃、芳烃、烯烃、卤代烃、卤代芳烃、含氧有机物等,有37种属有毒有害物质,其中苯系物含量最高;宁波市环境空气中苯系物的污染程度与国内外城市基本处于同一水平,近年来的污染状况变化不大,没有明显恶化;空间分布特征显示一类保护区VOCs的排放以天然源为主,二类各功能区VOCs的排放由天然源和局部人为污染源共同形成,三类区以工业污染源排放为主;时间变化趋势显示VOCs在冬季和春季的平均浓度比其他季节高,VOCs的日变化基本呈现2个主浓度峰值特征,跟城市交通流量变化具有很好相关性。     

典型化工园区大气中挥发性有机物污染调查

对常州市某典型化工园区大气中挥发性有机物(VOCs)污染状况进行了调查。结果表明,该化工园区大气中检出挥发性有机物共有58种,组分有芳香烃、饱和烷烃、卤代烃、烯烃、醛酯类化合物及其他类;苯、甲苯、乙苯、二甲苯为主要挥发性有机污染物,质量浓度为1.0~194μg/m~3;均未超出参考标准的限值。背景点位和园区点位大气中主要ρ总(VOCs)在秋冬季最高,敏感点大气VOCs随季节变化也较为明显;园区T1和T2ρ总(VOCs)年均值高于敏感点位,背景点位年均值最低;园区点位除了汽车尾气排放之外,溶剂的挥发和生产工艺中污染物的排放也增加了大气中苯系物的浓度,同时也对敏感点位和对照点位的大气质量产生了一定的影响。     

吹扫—捕集／气相色谱法测定水中挥发性有机物

为提高样品分析效率,研究并建立了吹扫-捕集／气相色谱／氢火焰检测器联用同时测定水中1,2-二氯乙烷、苯、甲苯、氯苯、乙苯、对-二甲苯、间-二甲苯、苯乙烯、邻-二甲苯、异丙苯、1,4-二氯苯、1,2-二氯苯、硝基苯、1,3,5-三氯苯、1,2,4-三氯苯、1,2,3-三氯苯、六氯丁二烯17种挥发性有机物的分析方法。结果表明,当进样体积为25．0ml时,最低检出限为0．0034-0．1088μg/L,相对标准偏差为1．8％～6．4％,加标平均回收率为97．6％-105．8％。该方法可快速、简便、准确、高灵敏度的测定水中17种挥发性有机物,并适用于饮用水和地表水中挥发性有机物的测定。     

某废弃农药生产场地地下水挥发性有机物污染健康风险评价

对常州某废弃农药生产场地地下水中挥发性有机物污染状况和健康风险进行了调查评价。结果表明,该场地地下水中挥发性有机物污染以苯系物、氯代苯类和氯代烃类为主;部分点位地下水健康风险评价结果超出可接受范围,可能危害人体。