模拟大气颗粒物混合元素滤膜标准样品的研制与质量考察

用能量色散X射线荧光光谱法(ED-XRF)测定大气颗粒物滤膜样品中Na、Mg、Al、Si、P、S、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Pb、Sr、Ba等无机元素的HJ 829—2017标准已颁布实施多年。颗粒物滤膜标准样品对于校准曲线的建立、评估具有重要意义。目前市场仅有美国NIST SRM 2783一种模拟大气颗粒物滤膜标准样品,价格昂贵,基层实验室在日常检测工作中很难用于质控工作。没有价格合适、质量符合要求相关产品投放市场,基层实验室大气颗粒物元素XRF分析质控工作就无法落实。借鉴国外模拟大气颗粒物滤膜标样制备方法,以湖南污染土壤标样为加工原材料,经进一步粉碎后,利用表面活性剂将细颗粒物制成悬浊液,定量、均匀分布在多孔滤膜上。6家ED-XRF实验室,1家质子激发X荧光光谱分析(PIXE)和1家中子活化分析(NAA)实验室,对同批次制备的120张滤膜样品随机抽取14张进行了测试,对滤膜上20多种元素测定结果的准确度和精密度进行了评估。初步分析结果表明:Al、Fe、Zn、As、Ba、Ti、Pb等元素含量与依据土壤标样元素认定值比值推算的结果基本相符;Al、Si、Fe、Ti、Mn、Zn、K、As、Pb等元素含量相对标准偏差(RSD)范围为6.8%~21%,基本满足滤膜质控样品要求,可以提供给基层实验室试用。提出了后续研究工作思路及计划。

Development and quality inspection of standard samples of simulated atmospheric particulate mixed elements filter membrane

The standard of HJ 829-2017, which is concerning the determination of inorganic elements such as Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Pb, Sr and Ba in atmospheric particulate filter membrane sample by energy dispersive X-ray fluorescence spectrometry (ED-XRF), has been issued and implemented for several years. The standard sample of particulate filter membrane is of great significance for the establishment and evaluation of calibration curves. At present, there is only one standard sample for simulating particulate filter membrane (NIST SRM 2783, USA) in the market. But the price is expensive, and it is difficult to be used in quality control for the primary-level laboratories in routine analysis. If there is no relevant product with appropriate price and quality that meets the requirements, the quality control of XRF analysis for the testing of atmospheric particulate elements will be hardly implemented in primary-level laboratories. Refer to the preparation method of foreign simulated atmospheric particulate filter membrane, the standard sample of polluted soil sampled from Hunan was used as raw materials. After further pulverization, the fine particles were made into a suspension by using surfactant. Then the suspension was quantitatively and uniformly distributed on the porous filter membrane. Total 120 pieces of filter membrane samples were prepared in one batch and 14 of them were randomly selected for testing by 6 ED-XRF laboratories, one proton induced X-ray emission (PIXE) laboratory and one neutron activation analysis (NAA) laboratory. The determination accuracy and precision of measuring results of more than 20 elements on filter membrane were evaluated. The preliminary analysis results showed that the contents of Al, Fe, Zn, As, Ba, Ti and Pb were basically consistent with the results calculated based on the ratio of certified values of elements in soil standard sample. The relative standard deviations (RSD) of Al, Si, Fe, Ti, Mn, Zn, K, As and Pb were between 6.8% and 21%, which could basically meet the requirements of filter membrane samples for quality control. They could be provided to the primary-level laboratories for trial test. The ideas and plans for follow-up research work were proposed.