Zhang D, Liang H, Zeng J, Rao G
Department of Pharmaceutical Analysis, First Affiliated Hospital.
Hua Xi Yi Ke Da Xue Xue Bao. 1995 Dec;26(4):447-51.
This paper reports a new RP-HPLC method using phenacetin internal standard (IS) for simultaneous determination of chlorhexidine (CH) and its impurity 4-chloroaniline (4-CA). We use the LC-3A HPLC instrument, a Zorbax-C8 column (25cm x 4.6mm id, 10 microns), a variable wave length UV detector and C-RIA chromatographic data processor. A mixture of methanol and 0.2 mol/L NaH2PO4 (50.5 : 49.5, pH 3.0) is used as mobile phase, whose flow rate is 1.0 ml/min. Sample solution of 15 microliters is injected onto the column, which is maintained at 30 degrees C. The eluent is monitored at 240nm. The retention times are 16.72 min for CH and 5.54 min for 4-CA. The standard curves of CH and 4-CA are established using peak area ratio of CH/IS and 4-CA/IS to concentration respectively. They are both linear (r = 0.9999) within 15-200 micrograms/ml for CH and 60-1200 micrograms/ml for 4-CH. The limits of detection are 1.33 micrograms/ml for CH AND 7.5 micrograms/ml for 4-CA (S/N = 3). The analytical recovery rates are 100.1% for CH and 103.1% for 4-CA. This method has been used for investigating the stability of CH preparation.
本文报道了一种采用非那西丁内标（IS）的新型反相高效液相色谱（RP-HPLC）方法，用于同时测定洗必泰（CH）及其杂质4-氯苯胺（4-CA）。我们使用LC-3A高效液相色谱仪、Zorbax-C8柱（25cm×4.6mm内径，10微米）、可变波长紫外检测器和C-RIA色谱数据处理器。以甲醇和0.2mol/L磷酸二氢钠的混合物（50.5:49.5，pH 3.0）作为流动相，流速为1.0ml/min。将15微升的样品溶液注入柱中，柱温保持在30℃。在240nm波长下监测洗脱液。CH的保留时间为16.72分钟，4-CA的保留时间为5.54分钟。分别以CH/IS和4-CA/IS的峰面积比与浓度建立CH和4-CA的标准曲线。CH在15-200微克/毫升范围内、4-CA在60-1200微克/毫升范围内均呈线性（r = 0.9999）。CH的检测限为1.33微克/毫升，4-CA的检测限为7.5微克/毫升（信噪比=3）。CH的分析回收率为100.1%，4-CA的分析回收率为103.1%。该方法已用于研究CH制剂的稳定性。
