差示扫描量热法测定对乙酰氨基酚原料药纯度

Determination of the purity of 4-acetamidophenol by differential scanning calorimetry

建立差示扫描量热(DSC)法测定对乙酰氨基酚原料药纯度的方法。考察升温速率、称样量、坩埚类型对测定结果的影响,确定最佳测定条件:升温速率为1.0℃/min,称样量为2.0~2.2 mg,选用Tzero密封铝坩埚作为样品盘。DSC法测定对乙酰氨基酚原料药纯度为99.91%,测定结果的相对标准偏差为0.03%(n=6),DSC法测定结果与紫外可见分光光度法测定结果(99.85%)基本一致,且DSC法测定结果的相对标准偏差较小。该方法简便、快速、准确,无需标准品,可用于对乙酰氨基酚原料药纯度的测定。

The method of using differential scanning calorimetry technique to detect the purity of 4-acetamidophenol was established.The effects of heating rate,sample mass and crucible type on the determination results were investigated.The optimized experimental conditions were as following:the heating rate was 1.0℃/min,the sample mass was 2.0-2.2 mg,Tzero hermetic aluminum crucible was used as sample pan.The purity of 4-acetamidophenol determined by DSC was 99.91%,the relative standard deviation of the determination results was 0.03%(n=6).The result determined by DSC agreed with the purity detected by UV-Vis spectrophotometry,and the relative standard deviation of the determination results of DSC was small.The DSC method is simple,rapid,accurate,and without the need of standard substance,which can be used for the determination of 4-acetamidophenol purity of crude drug.