加权最小二乘法建立皮革中游离甲醛含量分析标准曲线的研究

摘要

化学分析工作中，两个变量之间的关系一般采用最小二乘法建立标准曲线，如果分析测定的变量范围宽，在低浓度区域则分析结果的相对误差较大，本文主要讨论了以加权最小二乘法建立标准曲线的优越性，并以GB/T 19941-2005乙酰丙酮法测皮革中游离甲醛为应用实例，介绍了加权最小二乘法的原理、计算公式、权重因子在提高低浓度测定相对误差的作用。%In chemical analysis, the relationship between two variables, least squares method is adopted to establish the standard curve. If the analysis variable scope is wide, in low concentration region the results of the analysis of relative error is larger. This paper mainly discusses with the weighted least squares method to establish the superiority of the standard curve. By taking acetyl acetone method described in GB/T19941-2005 as example, free formaldehyde in leather is determined. in which the principle of weighted least squares method, calculation formula and in impact of weighting factor on decreasing the measuring relative error in low concentration is discussed.