Harper Martin, Hallmark Timothy S, Andrew Michael E, Bird Aaron J
Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS-3030, Morgantown, WV 26505, USA.
J Environ Monit. 2004 Oct;6(10):819-26. doi: 10.1039/b405023c. Epub 2004 Sep 22.
Personal and area air samples were taken at a scrap lead smelter operation in a bullet manufacturing facility. Samples were taken using the 37-mm styrene-acrylonitrile closed-face filter cassette (CFC, the current US standard device for lead sampling), the 37-mm GSP or "cone" sampler, the 25-mm Institute of Occupational Medicine (IOM) inhalable sampler, and the 25-mm Button sampler (developed at the University of Cincinnati). Polyvinylchloride filters were used for sampling. The filters were pre- and post-weighed, and analyzed for lead content using a field-portable X-ray fluorescence (XRF) analyzer. The filters were then extracted with dilute nitric acid in an ultrasonic extraction bath and the solutions were analyzed by inductively coupled plasma optical emission spectroscopy. The 25-mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37-mm filters. The single reading from the 25-mm filters was adjusted for the nominal area of the filter to obtain the mass loading, while the three readings from the 37-mm filters were inserted into two different algorithms for calculating the mass loadings, and the algorithms were compared. The IOM sampler was designed for material collected in the body of the sampler to be part of the collected sample as well as that on the filter. Therefore, the IOM sampler cassettes were rinsed separately to determine if wall-loss corrections were necessary. All four samplers gave very good correlations between the two analytical methods above the limit of detection of the XRF procedure. The limit of detection for the 25-mm filters (5 microg) was lower than for the 37-mm filters (10 microg). The percentage of XRF results that were within 25% of the corresponding ICP results was evaluated. In addition, the bias from linear regression was estimated. Linear regression for the Button sampler and the IOM sampler using single readings and the GSP using all tested techniques for total filter loading gave acceptable XRF readings at loadings equivalent to sampling at the OSHA 8-hour Action Level and Permissible Exposure Limit. However, the CFC only had acceptable results when the center reading corrected for filter area was used, which was surprising, and may be a result of a limited data set. In addition to linear regression, simple estimation of bias indicated reasonable agreements between XRF and ICP results for single XRF readings on the Button sampler filters, (82% of the individual results within criterion), and on the IOM sampler filters (77% or 61%--see text), and on the GSP sampler filters using the OSHA algorithm (78%). As a result of this pilot project, all three samplers were considered suitable for inclusion in further field research studies.
在一家子弹制造工厂的废旧铅冶炼作业现场采集了个人空气样本和区域空气样本。样本采集使用了37毫米苯乙烯 - 丙烯腈封闭式滤膜盒（CFC，美国目前用于铅采样的标准设备）、37毫米GSP或“锥形”采样器、25毫米职业医学研究所（IOM）可吸入采样器以及25毫米纽扣采样器（由辛辛那提大学研发）。使用聚氯乙烯滤膜进行采样。对滤膜进行采样前和采样后的称重，并使用现场便携式X射线荧光（XRF）分析仪分析铅含量。然后将滤膜在超声萃取浴中用稀硝酸萃取，萃取液通过电感耦合等离子体发射光谱法进行分析。25毫米滤膜使用XRF单次读数进行分析，而37毫米滤膜则在滤膜的不同部位进行三次读数。25毫米滤膜的单次读数根据滤膜的标称面积进行调整以获得质量负荷，37毫米滤膜的三次读数则代入两种不同的算法来计算质量负荷，并对这两种算法进行比较。IOM采样器的设计使得采样器主体内收集的物质以及滤膜上收集的物质都成为采集样本的一部分。因此，对IOM采样器盒进行单独冲洗以确定是否需要进行壁损失校正。在XRF方法的检测限以上，所有四种采样器在上述两种分析方法之间都具有很好的相关性。25毫米滤膜的检测限（5微克）低于37毫米滤膜的检测限（10微克）。评估了XRF结果在相应ICP结果的25%范围内的百分比。此外，还估计了线性回归的偏差。对于纽扣采样器和IOM采样器，使用单次读数进行线性回归，对于GSP采样器，使用所有测试技术对滤膜总负荷进行线性回归，在相当于按照职业安全与健康管理局（OSHA）8小时行动水平和允许接触限值进行采样的负荷下，得到了可接受的XRF读数。然而，只有当使用根据滤膜面积校正后的中心读数时，CFC才得到可接受的结果，这很令人惊讶，可能是由于数据集有限所致。除了线性回归外，偏差的简单估计表明，对于纽扣采样器滤膜上的XRF单次读数、（82%的个体结果符合标准）、IOM采样器滤膜上的XRF单次读数（77%或61% - 见正文）以及使用OSHA算法的GSP采样器滤膜上的XRF单次读数，XRF和ICP结果之间具有合理的一致性。作为这个试点项目的结果，所有三种采样器都被认为适合纳入进一步的现场研究。
