室内空气污染物中氨的测定分析方法探讨

研究了(纳氏试剂比色法和次氯酸钠—水杨酸分光光度法)在室内空气监测中存在的问题,得出次氯酸钠—水杨酸分光光度法不适合于装修后有机物含量较高的室内空气监测的结论。同时,针对纳氏试剂比色法分别进行了不同采样时间、不同采样流量以及不同吸收瓶等条件下室内空气中氨的监测技术的研究,确定了室内空气中氨的最佳监测条件。     

分光光度法测定室内空气中甲醛的方法研究

针对室内空气中甲醛的特点,在环境空气甲醛的测定方法—乙酰丙酮分光光度法(GB/T15516-95)的基础上,进一步优化了该方法的采样时间、采样流量、样品收集器等,使优化后的测定方法更加适应室内空气监测需要的准确性、简便性、快速性的特点。     

比色法快速测定室内空气甲醛含量

室内空气甲醛的现场快速监测技术已成为环境监测的热点研究领域,旨在为普通家庭提供室内空气甲醛现场监测方法。优化了甲醛吸收液用量、自然吸收时间及吸收液与空气接触面积对监测方法的影响,制作了用于目测室内空气中甲醛含量的标准比色卡,方法简便、快速、经济、实用,可望在普通家庭中得到广泛应用。     

预冷浓缩系统与气相色谱——质谱法测定室内空气中挥发性有机物

针对室内空气挥发性有机物测定方法的不足，本文采用预冷浓缩系统和气相色谱，质谱联用。建立了测定室内空气中39种挥发性有机物的分析方法，该方法采用苏码罐采样，经液氮预冷冻浓缩后，用心城由检测。该方法灵敏度高，操作简便、重现性好、准确度高，适用于室内空气中挥发性有机物的测定。     

室内空气NO_2污染——扩散式NO_2简易检测器的应用

目前的常规监测方法所用的采样设备很难适应广范围、多点、同步测定的需要。本文作者从1986年开始研究扩散式空气NO_2无动力采样的简易检测技术,1989年7月研制成功的扩散式NO_2检测器通过了国家环保局主持的专家鉴定。同年9月,作者利用该检测器进行了室内空气NO_2污染调查列车车厢内NO_2污染调查。     

公共场所可吸入尘(IP)测定时滤膜处理及分析中若干问题

可吸入尘(IP)作为主要的空气质量监测指标之一,已广泛应用于环境监测工作中,尤其是大气卫生监测和公共场所及住宅室内空气卫生状况的调查,并已制定出相应的卫生标准.目前国内广泛采用的测定方法均为分级采样器——滤膜称重法,本法在空气颗粒物质浓度较高,且可长时间采样的现场监测中,结果还是比较稳定     

空气中挥发性有机化合物的采样及分析方法进展

空气中挥发性有机化合物的采样及分析方法进展①徐东群崔九思（中国预防医学科学院环境卫生监测所，北京１０００２１）挥发性有机化合物（以下简称ＶＯＣＳ）是指沸点范围在５０－２６０℃的化合物，这类化合物普遍存在于室内外空气中，且室内空气中的浓度明显高于室外。...     

空气污染物采样精度统计分析

我国将在一定时期内对大气环境中二氧化硫(SO_2)及氮氧化物(NO_x)污染监测采用三种不同监测方法共存的方针,即采用间断采样实验室分析法、24小时连续采样实验室分析法及连续自动监测法。由于这三种监测方法所采用的采样方法及分析方法各不相同,因此监测结果必然存在着不同程度的差异。监测结果的准确性、可靠性及代表性不仅依赖于分析方法,而且在很大程度上依赖于采样方法。而采样精度表示样品的代表性,它受污染物排放特征、扩散机理、采样频数、采样时段及置信水平等因素的影响。本文以大量实地监测数据依据,用统计分析的方法,对不同监测点所采用的不同监测方法的采样精度进行了比较。推荐一种估计采样精度的方法。     

甲醛的共存对靛酚蓝分光光度法测定室内空气氨含量的影响研究

在对室内空气氨气的采样过程中不可避免地会将室内空气中共存的甲醛引入到氨吸收液中,考察了不同浓度甲醛的共存对使用靛酚蓝法测定室内空气氨含量的影响情况,分析了影响产生的原因,提出了相应的建议,可供从事室内环境检测的工作人员参考。     

利用自动采样滤膜监测PM_(2.5)中铅和镉的可行性

根据PM2.5中重金属监测国标分析方法,从PM2.5采样方法、采样保存条件、滤膜材质性能等方面说明利用空气自动采样滤膜监测PM2.5中铅和镉是可行的;对手工采样(石英滤膜)和Beta射线法自动采样(自动采样滤膜)2种方法,对PM2.5实际样品中铅和镉的结果进行比较,结果显示:自动采样滤膜的空白检出和检出限均满足铅和镉的监测需求,铅和镉的回收率分别为95.2%~107%和91.8%~105%,与手工采样方法相比测得铅和镉的相对误差分别为3.6%~8.4%和1.3%~10.8%,从实践角度进一步证明了利用自动采样滤膜对PM2.5中铅和镉进行监测是可行的。     

中红外光谱法快速测定车内空气中多组分有机污染物

随着汽车进入家庭,车内空气质量越来越受到人们的重视,亟需建立一种车内空气中有机污染物的快速测定方法以满足日常监测需要。将中红外光谱技术与化学计量学方法相结合,建立了一种快速测定车内空气中苯系物的方法。以偏最小二乘法(PLS)建立分析预测模型,并对光谱预处理方法、主因子数进行了优化。最佳校正模型对苯、甲苯、二甲苯浓度的校正均方差、预测均方差和交叉验证均方差分别为0.0089、0.0200和0.1115,0.0116、0.0011 和0.1398以及0.0137、0.0037和0.1390。研究表明,该方法具有较高的准确度和较好的适用性,用于测定车内空气中苯系物的浓度是可行的,并能大大提高车内空气质量监测的效率。     

Airborne particulate matter and BTEX in office environments

Total suspended particulate (TSP), PM(2.5) and BTEX were collected in nine offices in the province of Antwerp, Belgium. Both indoor and outdoor aerosol samples were analysed for their weight, elemental composition, and water-soluble fraction. Indoor TSP and PM(2.5) concentrations ranged from 7-31 microg m(-3) and 5-28 microg m(-3), with an average of 18 and 11 microg m(-3), respectively. Of all the elements analysed in indoor TSP, more than 95% was represented by Al, Si, K, Ca, Fe, Cl and S, accounting for 12% of the TSP by mass. The other elements showed significant enrichment relative to the earth's crust. The water-soluble ionic fraction accounted for almost 30% of the sampled indoor TSP by weight, and was enriched by anthropogenic activities. It was shown that the indoor PM levels varied among the offices, depending on the ventilation pattern, location, and occupation density of the office. Indoor BTEX levels ranged together from 5-47 microg m(-3) and were considerably higher than the corresponding outdoor levels. It was observed that some recently constructed and renovated buildings were clearly burdened with elevated levels for toluene, ethyl benzene, and xylenes, while outdoor air was found to be the main source for BTEX levels at the 'older' offices.     

预冷冻浓缩系统与气相色谱-质谱联用测定空气中挥发性有机物

采用预冷冻浓缩系统和气相色谱-质谱联用,建立了测定空气中39种挥发性有机物的分析方法,该法用苏玛罐或Tedlar气袋采集空气样品经-160℃液氮预冷冻浓缩后,用GC-MS检测.该方法采样简便,灵敏度、准确度高,已应用于室内空气和环境空气的测定,取得满意的结果.     

Application of portable gas chromatography-photo ionization detector combined with headspace sampling for field analysis of benzene, toluene, ethylbenzene, and xylene in soils

A method based on headspace (HS) sampling coupling with portable gas chromatography (GC) with photo ionization detector (PID) was developed for rapid determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in soils. Optimal conditions for HS gas sampling procedure were determined, and the influence of soil organic matter on the recovery of BTEX from soil was investigated using five representative Chinese soils. The results showed that the HS-portable-GC-PID method could be effectively operated at ambient temperature, and the addition of 15 ml of saturated NaCl solution in a 40-ml sampling vial and 60 s of shaking time for sample solution were optimum for the HS gas sampling procedure. The recoveries of each BTEX in soils ranged from 87.2 to 105.1 %, with relative standard deviations varying from 5.3 to 7.8 %. Good linearity was obtained for all BTEX compounds, and the detection limits were in the 0.1 to 0.8 μg kg^?1 range. Soil organic matter was identified as one of the principal elements that affect the HS gas sampling of BTEX in soils. The HS-portable-GC-PID method was successfully applied for field determination of benzene and toluene in soils of a former chemical plant in Jilin City, northeast China. Considering its satisfactory repeatability and reproducibility and particular suitability to be operated in ambient environment, HS sampling coupling with portable GC-PID is, therefore, recommended to be a suitable screening tool for rapid on-site determination of BTEX in soils.     

Indoor air pollution levels in public buildings in Thailand and exposure assessment

Levels of pollutants including PM2.5 and PM2.5 composition (black carbon and water soluble ions), SO(2), NO(2), CO, CO(2), and BTEX (benzene, toluene, ethylbenzene, xylene) were monitored for indoor and outdoor air at a university campus and a shopping center, both located in the Northern suburb of Bangkok. Sampling was done during December 2005-February 2006 on both weekdays and weekends. At the university, indoor monitoring was done in two different air conditioned classrooms which shows the I/O ratios for all pollutants to be below 0.5-0.8 during the weekends. However, on weekdays the ratios for CO(2) and most detected BTEX were above 1.0. The concept of classroom occupancy was defined using a function of the student number in a lecture hour and the number of lecture hours per day. Classroom 2, which had a higher occupancy than classroom 1, was characterized by higher concentrations of most pollutants. PM2.5 was an exception and was higher in classroom 1 (37 microg/m(3), weekdays) as compared to classroom 2 (26 microg/m(3), weekdays) which was likely linked to the dust resuspension from the carpeted floor in the former. Monitoring was also done in the shopping mall at three different sites. Indoor pollutants levels and the I/O ratios at the shopping mall were higher than at the university. Levels of all pollutants measured at the car park, except for toluene and CO(2), were the highest. I/O ratios of the pollutants at the mall were above 1.0, which indicates the relatively higher influence of the indoor sources. However, the black carbon content in PM2.5 outdoor is higher than indoor, which suggest the important contribution from outdoor combustion sources such as the traffic. Major sources of outdoor air pollution in the areas were briefly discussed. Exposure modeling was applied using the time activity and measured pollutant concentrations to assess the exposure of different groups of people in the study areas. High exposure to PM2.5, especially for the people working in the mall, should be of health effect concern.     

便携式质谱仪应用于交通干线苯系物污染特征分析

介绍了EcoSys-P便携式质谱仪在无车日前后对交通干线环境空气中苯系物现场监测中的情况,同时该方法与经典的气相-质谱联机进行了对比试验,相对偏差≤25%,能够满足交通干线环境空气苯系物的现场监测要求.     

Personal, indoor, and outdoor exposure to VOCs in the immediate vicinity of a local airport

This study measures the effect of emissions from an airport on the air quality of surrounding neighborhoods. The ambient concentrations of benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) were measured using passive samplers at 15 households located close to the airport (indoor, outdoor, and personal), at the end of airport runways and an out-of-neighborhood location. Measurements occurred over a 48-h period during summer 2006 and winter 2006?C2007. The average concentrations were 0.84, 3.21, 0.30, 0.99, and 0.34 ??g/m³ at the airport runways and 0.84, 3.76, 0.39, 1.22, and 0.39 ??g/m³ in the neighborhood for benzene, toluene, ethylbenzene, m-, p-, and o-xylene. The average neighborhood concentrations were not significantly different to those measured at the airport runways and were higher than the out-of-neighborhood location (0.48, 1.09, 0.15, 0.78, and 0.43 ??g/m³, each BTEX). B/T ratios were used as a tracer for emission sources and the average B/T ratio at the airport and outdoors were 0.20 and 0.23 for the summer and 0.40 and 0.42 for the winter, suggesting that both areas are affected by the same emission source. Personal exposure was closely related to levels in the indoor environment where subjects spent most of their time. Indoor/outdoor (I/O) ratios for BTEX ranged from 1.13 to 2.60 and 1.41 to 3.02 for summer and winter. The seasonal differences in I/O ratios reflected residential ventilation patterns, resulting in increased indoor concentrations of volatile organic compounds during winter.     

上海城区交通干道苯系物污染初探

利用设置在上海市中心城区交通主干道旁的路边空气质量自动监测站2018年1—12月的连续观测数据,研究苯系物(BTEX)污染水平、变化特征以及其与CO、NO x和气象参数的关系。结果表明,观测期间BTEX小时均值为0.10~169.38μg/m^3,年均值为(13.66±0.14)μg/m^3,甲苯占比最高。ρ(BTEX)受污染源排放强度和天气状况的影响大,其日变化呈单谷型,冬季值比夏季高。BTEX各化合物具有较好的同源性,ρ(苯)/ρ(甲苯)为(0.49±0.01)。BTEX与机动车尾气主要成分CO、NOx呈正相关,与风速负相关。其值低于北京、南京、郑州、杭州和西安等城市。     

Indoor and outdoor air concentrations of BTEX and NO2: correlation of repeated measurements

Studies on health effects of air pollutants ideally define exposure through the collection of air samples in the participants' homes. Concentrations derived from these samples are then considered as an estimate for the average concentration of air pollutants in the homes. Conclusions drawn from such studies therefore depend very much on the validity of the measured air pollution concentrations. In this paper we analysed repeated BTEX and NO(2) measurements with a time period of several months lying between the two conducted home visits. We investigated the variability of their concentrations over time by determining correlation coefficients and calculating within- and between-home variances. Our population consisted of 631 homes of participants from two cohort studies within the framework of the German study on Indoor Factors and Genetics in Asthma. Air pollutants were measured using passive samplers both indoors and outdoors. The measured BTEX concentrations were poorly correlated, with Pearson's correlation coefficient r ranging from -0.19 to 0.27. Additionally, a considerable seasonal effect could be observed. A higher correlation was found for the NO(2) concentrations with r ranging between 0.24 and 0.55. For the BTEX, the between-home variance was bigger than the within-home variance, for NO(2) both variances were of about the same order. Our results indicate that in a setting of moderate climate like in Germany, the variability of BTEX and NO(2) concentrations over time is high and a single measurement is a poor surrogate for the long-term concentrations of these air pollutants.