摘要：测定环己烷原料苯纯度的方法，旧标准采用ASTM D4492和QSHPRD399，标准更新后采

用 ASTM D7504。苯是致癌物，内标法操作步骤多，操作人员暴露风险大，且称量样品和加内

标物增加了成本，整个分析时间较长。新标准中校正因子归一化法能够解决内标法的不足，

提高了分析效率。文中对 2 种方法分析的不确定度进行了研究，对其产生的误差进行了探

讨。归一化法没有明显不确定来源，而内标法测烃杂的不确定度有±0.000 2%，主要来自重

复实验的A类不确定度，直接影响了苯纯度的计算，而B类不确定度影响很小。

Abstract: The previous method for the purity analysis of cyclohexane raw benzene is ASTM D4492 and QSHPRD399 in the old

standard,and ASTM D7504 is updated standard. Benzene is a carcinogen,and the internal standard method involves multiple steps,

which increases the risk of exposure for operators. In addition, weighing samples and adding internal standards increase laboratory

costs,and the entire analysis time is relatively long. The apply of calibration factor normalization method in the new standard can

effectively solve the problem of the internal standard method and improve analysis efficiency. This article also study the uncertainty

of two analysis methods and explore the errors they generated.The normalization method has no obvious source of uncertainty, whilethe internal standard method has an uncertainty of ± 0.0002% for measuring hydrocarbon impurities, mainly due to the A-classuncertainty from repeated experiments, which directly affects the calculation of benzene purity, while the B-class uncertainty haslittle impact.