摘要
区域地球化学样品长期以来一直是采用间接方法对实际样品元素分析质量进行评价,有效地提高了区域地球化学样品的整体分析质量,但是当实际样品和外部质量控制样品含量范围差别较大时,间接评价的效果会减弱。本文从区域地球化学样品大部分元素符合标准(对数)正态分布的规律出发,运用SPSS、Excel等软件对区域地球化学调查样品元素含量正态分布情况进行研究,通过计算元素含量实际正态分布图和标准正态分布图的重合度直接评价元素的分析质量。运用整套方法对实验室分析的江西某地多目标区域地球化学样品的分析数据进行了质量评价,正态分布检验表明微量元素需要通过对数转换才能进行正态分布分析,该地区钛、钨、铬等元素不适合用本方法进行质量评价;钴、汞、镓等18个元素的重合度都在0.9以上;氧化钙和氧化钠重合度小于0.9,样品实际结果分析表明需降低分析方法检出限,提高低含量氧化钙和氧化钠的分析质量。本方法对区域地球化学调查样品的分析数据质量的直接评价作了有益的尝试,可以作为现有区域地球化学调查样品质量评价办法的参考和补充。
The quality of regional geochemical survey samples is currently estimated indirectly by internal and external laboratory quality control. The method described here effectively improves the quality of geochemical samples. However, the improvement of the method is limited when the contents of the actual samples and external quality control samples have large differences. Since most elements are in accord with a normal distribution in a regional geochemical sm＇vey sample, a comparison was made between the real and standard normal distribution of the elements, which passed the normal distribution test and gave an estimate of the quality by using a comparison of the real and standard graph＇s superposition using SPSS and Excel software. This method was directly applied to estimate the quality of analysis data for geochemical survey samples in Jiangxi province. The result of the normal distribution test indicated that the analysis data of the trace elements need a logarithmic conversion before the normal distribution can be studied. The quality evaluation method in this paper was not suitable for Ti, W and Cr etc in this area. The overlap ratios of 18 elements such as Co, Hg and Ga were more than 0.9. The overlap ratios of CaO and Na20 were less than 0.9. The results of the actual samples indicated that the detection limits need to be reduced in order to improve the analysis qualities of CaO and Na20. It was a valuable attempt to directly evaluate the quality of analysis data for regional geochemical survey samples by using the method reported in this paper, which was a reference and supplement for the current methods of quality evaluation.
出处
《岩矿测试》
CAS
CSCD
北大核心
2013年第1期96-100,共5页
Rock and Mineral Analysis
关键词
区域地球化学调查样品
质量评价
正态分布
对数正态分布
regional geochemical sm,cey sample
quality evaluation
normal distribution
logarithmic normal distribution
