某品种有关物质和含量测定

Assay—

含量测定：

Phosphate buffer— Dissolve 0.6 g of monobasic potassium phosphate and 0.35 g of dibasic sodium phosphate in 900 mL of water, dilute with water to 1 L, and mix.

磷酸盐缓冲液：称取磷酸二氢钾0.6g和磷酸氢二钠0.35g，置1000ml量瓶中，加水900ml使溶解并稀释至1000ml，摇匀。

Mobile phase— Prepare a mixture of acetonitrile and Phosphate buffer (750:250).

流动相：磷酸盐缓冲液（称取磷酸二氢钾0.6g和磷酸氢二钠0.35g，置1000ml量瓶中，加水900ml使溶解并稀释至1000ml，摇匀）-乙腈（75：25）

Make adjustments if necessary (see System Suitability under Chromatography ).

如有需要，流动相可以适当调整（参见色谱系统适用性621章节）。

Standard preparation— Reconstitute a vial of USP Acarbose RS in 5.0 mL of water.

对照品溶液准备：向USP对照品小瓶中，加入5.0ml水，超声使溶解。

System suitability solution— Reconstitute a vial of USP Acarbose System Suitability Mixture RS in 1 mL of water.

系统适用性试验溶液：向USP系统适用性对照品小瓶中，加入1.0ml水，超声使溶解。

Assay preparation— Transfer about 200 mg of Acarbose, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with water to volume, and mix.

供试液：取约200mg阿卡波糖，精密称定，置10ml量瓶中，加水适量使溶解并稀释至刻度，摇匀。

Chromatographic system (see Chromatography )— The liquid chromatograph is equipped with a 210-nm detector and a 4-mm × 25-cm column that contains packing L8. The flow rate is about 2 mL per minute. The column temperature is maintained at 35.

色谱条件：

色谱柱：氨基柱（4*250mm），即USPL8。210nm，2ml/min流速，柱温35℃。

Chromatograph the System suitability solution, and identify the acarbose peak and the peaks due to the impurities listed in Table 1. Record the peak responses as directed for Procedure: the ratio of the height of the impurity A peak to the height of the valley between the impurity A peak and the acarbose peak is not less than 1.2. The chromatogram obtained is similar to the chromatogram supplied with USP Acarbose System Suitability Mixture RS.

色谱系统适应性溶液，判别阿卡波糖峰以及表1中所列的杂质峰。记录峰响应程序：杂质杂质A峰和阿卡波糖峰之间的峰高和峰谷比值不小于1.2 。得到的色谱图中类似于USP阿卡波糖系统适用性混合RS提供的色谱图。

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for all the peaks. Calculate the quantity, in mg, of C25H43NO18 in the portion of Acarbose taken by the formula:

10C(rU / rS)

in which C is the concentration, in mg per mL, of USP Acarbose RS in the Standard preparation; and rU and rS are the acarbose peak responses obtained from the Assay preparation and the Standard preparation, respectively.