ジアゾ化滴定及び吸光検出高速液体クロマトグラフィーによるアミノ安息香酸エチル定量における不確かさ推定

抄録

A measurement uncertainty estimation in the determination of ethyl aminobenzoate by diazotization titration and HPLC with UV detection (HPLC-UV) was carried out. Fishbone diagrams for determining the ethyl aminobenzoate purity by diazotization titration and HPLC-UV were prepared for the identification of factors that affect measurement uncertainties. In the case of diazotization titration, combined standard uncertainties for titers of a sodium nitrite solution used in the standardization and determination were larger than that for other factors. In the case of the HPLC, combined standard uncertainties for the chromatographic peak areas of ethyl aminobenzoate in standard and sample solutions were larger than that for other factors. A determination of the ethyl aminobenzoate purity in the bulk powder was also carried out using diazotization titration and HPLC-UV. The results concerning the ethyl aminobenzoate purity by diazotization titration and HPLC-UV were 100.5% (RSD = 0.26%, n = 6) and 100.6% (RSD = 0.36%, n = 6), respectively, indicating that both analytical results were essentially identical. The estimated combined standard uncertainties were within the 95% confidence interval of SD, which were obtained by the above-mentioned repetitive measurements.