攜帶式X光螢光分析儀應用於作業環境砷暴露成效評估

Evaluation of the Use of Portable X-Ray Fluorescence for Work Environment Arsenic Exposure Assessment

朱萬澤(Wan-Tsh Chu)

指導教授 ： 黃耀輝

國立臺灣大學/公共衛生學院/職業醫學與工業衛生研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01918

摘要

本研究的目的是評估攜帶式X光螢光分析儀（XRF）用於偵測職場環境砷粉塵擦拭樣本之效度。評估方法可分為三方面：首先在實驗室部分，包括選擇適合之採集砷樣本的擦拭介質，以及建立擦拭樣本的標準分析程序。其次是攜帶式XRF量測含砷樣本的偵測極限與適用範圍的評估，以及此儀器進行砷定量時受干擾元素鉛的影響之探討。第三部份係XRF儀器在職場上運用的評估，係以職場工作環境取得的擦拭樣本進行比較，評估攜帶式XRF偵測職場環境含砷樣本的效度。針對實驗室製作的不同劑量含砷擦拭樣本標準品（5 ~ 5000 μg/sample），以攜帶式XRF量測的結果與ICP-MS的分析結果比較，其相關係數平方（r2）可達到0.997。若將攜帶式XRF的砷量測值經過實驗所得的變量係數轉換，則校正後XRF之砷量測值與標準分析方法的ICP-MS分析結果之相對誤差在±25%範圍內。綜合本研究所得結論如下：1. 攜帶式XRF量測實驗室製作之含砷標準樣本的偵測下限為4.8μg/sample，適用偵測範圍為16.1~ 5000.0 μg/sample。這可作為攜帶式XRF儀器用於作業環境砷暴露量測時適用性判斷的參考資料。2. 含砷擦拭樣本中若存在鉛元素對攜帶式XRF定量砷含量會有干擾，其干擾程度會隨著樣本含鉛量的提高而升高。對於鉛元素造成砷量測值的干擾可用下述模式進行校正：MICP-MS-As =-5.04＋1.38MXRF-As－0.16MXRF-Pb＋0.00018MXRF-As×MXRF-Pb （r2=0.996）。3. 本研究所採集的環境樣本內含有鎵元素，因鎵元素特性X光Kβ（10.26 Kev）與砷元素的特性X光Kα（10.5 Kev）相接近，以致在環境樣本以攜帶式XRF分析砷含量時，會因鎵元素的影響使儀器高估低砷含量之環境樣本的砷量測值。鎵元素對XRF儀器砷量測值的干擾可用下述模式進行校正：（r2=0.981）
log(M ICP-MS-As)= -3.55+ 5.37log(MXRF-As) –1.57log(MXRF-As)2 + 0.18log(MXRF-As)3

關鍵字

攜帶式X光螢光分析儀 ； 感應耦合電漿質譜儀 ； 擦拭採樣 ； 砷 ； 鉛 ； 鎵

並列摘要

The purpose of this study is to evaluate the validity of portable X-ray fluorescence (PXRF) use in work environment arsenic exposure assessment. Experiment design of the present study consisted of three parts. First of all, in the laboratory work, we chose an appropriate collection media and established standard operation procedure for wipe sampling. Secondly, detection limit and optimal range of quantification for arsenic collected on wipe sample were evaluated. At the same time, the interference of lead on the arsenic determination with PXRF for wipe sample was also examined. The final part was to evaluate the validity of PXRF use for arsenic exposure assessment in work field. There was a high correlation (r2=0.997) between the PXRF readings and the ICP-MS analysis results for arsenic sample dosed of 5.0~5000.0 μg/sample. If the PXRF arsenic readings were corrected by a factor derived from the present study, the adjusted PXRF readings are very close to ICP-MS analysis results, within ±25% of the relative error. Following are the conclusions obtained from the present study: 1. The detection limit for arsenic with PXRF is 4.8μg/sample and the optimal range for arsenic determination is 16.1~5000μg/sample, which could be used as guideline for choosing portable XRF in the work environment arsenic exposure assessment. 2. Arsenic quantification would be positively interfered for sample with lead content in sample. This kind of interference could be adjusted by following equation: MICP-MS-As =-5.04＋1.38MXRF-As－0.16MXRF-Pb＋0.00018MXRF-As×MXRF-Pb （r2=0.996）. 3. In this study, the field wipe samples contained gallium with characteristic radiation Kβ（10.26 Kev）, which was very close to arsenic’s characteristic radiation Kㄐ]10.26 Kev）. Therefore, the quantification of arsenic with PXRF for these field samples might be positively interfered due to the coexistence of gallium. Such an interference could be adjusted by the following equation: （r2=0.981）
log(M ICP-MS-As)= -3.55+ 5.37log(MXRF-As) –1.57log(MXRF-As)2 + 0.18log(MXRF-As)3

並列關鍵字

PXRF ； ICP-MS ； Wipe sampling ； Arsenic ； Lead ； Gallium

參考文獻

1. National Institute of Occupational Safety and Health (NIOSH). Manual of Analytical Method: Method No. 7702-Lead by portable XRF. Morley, MA: NIOSH, 1998; 4th ed.

2. Lawrence R. Lead on surface by a portable X-Ray Fluorescence analyzer. U.S. Department of Labor Occupational Safety & Health Administration, 2003.【2003 July 16】 Available from: URL:"http://www.osha.gov/dts/sltc/methods/onsite/oss1/oss1.htm"

3. Kalinicky DJ, Singhvi R. Field portable XRF analysis of environmental samples. J Hazard Mater 2001; 83:93-122.

4. Sterling DA, Roegner KC, Lewis RD, Luke DA, Wilder LC, Buchette SM. Evaluation of four sampling methods for determining exposure of children to contaminated household dust. Environ. Res. 1999; 80: 130-141.

7. Choe KT, Trunov M, Menrath W, Succop P. Relationship between lead level on painted surface and percent lead in the particles aerosolized during lead abatement. Appl Occup Environ Hyg 2002; 17(8): 573-579.