Analysis of Beta Attenuation Monitor Filter Rolls for Particulate Matter Speciation
Analysis of Beta Attenuation Monitor Filter Rolls for Particulate Matter Speciation
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用于颗粒物形态分析的 Beta 衰减监测过滤辊
DOI：
10.4209/aaqr.2016.03.0122
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发表时间：
2013
影响因子：
4
通讯作者：
K. Valsaraj
中科院分区：
文献类型：
--
作者：
S. James Raja;S. Chandrasekaran;Lin Lin;Xiaoyan Xia;P. Hopke;K. Valsaraj
β衰减仪（BAM）等仪器提供实时PM2. 5质量浓度数据，目前已广泛应用于合规监测网络。这些设备以1小时的样本收集过滤带上的PM。在这项工作中，使用BAM过滤点的化学形态进行了研究。对来自加州几个地点的过滤带进行了一系列化学物质分析，包括元素、离子、有机和元素碳以及分子标记。一个主要问题是过滤带中的空白值。根据空白点分析，确定有机和元素碳（OC/EC）和元素的测量是不可行的。对来自12个地点的总共22个BAM样品（每个样品包括24个1小时斑点）进行了离子和炭黑（BC）分析。此外，将336个1小时斑点合成以分析分子标记物（MM）。由于挥发损失，每个地点的离子和BC测量值似乎被低估了。MM测量在这336 BAM过滤器点表明，有机形态的BAM过滤器可能是一个可行的方法，用于测量有用的标记物种。通过将样品分组为质量浓度大于和小于80 µg m-3的类别进行统计分析。Delta-C浓度的测量（即，Δ C = BC 370 nm -BC 880 nm）表明，大多数高PM2.5浓度日（PM2.5大于80 µg m-3）可能基本上不受生物质燃烧颗粒的影响。在这项工作中分析的高浓度PM2.5样品的主要部分是无机物质，如硫酸铵，硝酸铵和其他离子。结果表明，一些有用的信息可能来自BAM磁带分析。然而，不同的过滤基质和样品处理和储存实践可能使更广泛的分析成为可能。
ABSTRACTInstruments such as Beta Attenuation Monitors (BAMs) provide real-time PM2.5 mass concentration data and are now widely used in compliance monitoring networks. These devices collect the PM on a filter tape in 1-hour samples. In this work, the use of BAM filter spots for chemical speciation was investigated. Filter tapes from several sites in California were analyzed for a series of chemical species including elements, ions, organic and elemental carbon, and molecular markers. A major issue was the blank values in the filter tape. Based on blank spot analyses, it was determined that measurement of organic and elemental carbon (OC/EC) and elements were infeasible. A total of 22 BAM samples (each comprising 24 1-hour spots) from 12 sites were analyzed for ions and black carbon (BC). Additionally, 336 1-hour spots were composited to analyze for molecular markers (MM). Measurements of ions and BC at each site appear to have been underestimated likely due to volatilization losses. MM measurements in these 336 BAM filter spots suggest that organic speciation of BAM filters could be a viable method for measuring useful marker species. Statistical analysis was conducted by grouping samples into classes with mass concentrations greater and less than 80 µg m–3. Measurement of Delta-C concentrations (i.e., Delta C = BC370 nm – BC880 nm) in these two groups of samples revealed that most of the high PM2.5 concentration days PM2.5 greater than 80 µg m–3) were likely not substantially impacted by biomass combustion particles. A major portion of the samples analyzed in this work with high concentrations of PM2.5 were inorganic species such as ammonium sulfate, ammonium nitrate and other ions. Results suggested that some useful information may be derived from BAM tape analyses. However, different filter substrates and sample handling and storage practice might make a wider range of analyses possible.