核磁共振法测定片剂中西咪替丁

Determination of Cimetidine in Tablets by NMR

建立以核磁共振技术测定片剂中西咪替丁含量的方法。采用Agilent DD2–500 型核磁共振波谱仪，以氘代甲醇为溶剂、对苯二甲酸二甲酯为内标，测试温度25℃，弛豫时间为20 s，脉冲角为45°，采集时间为2 s，扫描次数为16 次，采集核磁共振氢谱。该方法线性范围为0.1~5.0 mg／mL，相关系数r=0.999 8，测定结果的相对标准偏差为0.11%(n=6)，平均加标回收率在100.03%～100.58% 之间。用该方法测定不同厂家片剂中西咪替丁的含量，测定结果与药典方法相吻合。该方法简单快速、样品用量少，适用于西咪替丁的质量控制。

A method for the determination of cimetidine in tables by proton nuclear magnetic resonance spectroscopy (1H NMR) was established. The 1H NMR spectra was obtained in MeOD with dimethyl terephthalate as the internal standard by using Agilent DD2–500 MHz spectrometer. For each sample,16 scans were recorded with the following parameters:pulse angle was 45°, relaxation delay was 20 s,acquisition time was 2 s, the temperature was set at 25℃ . The linear range was 0.1–5.0 mg/mL with correlation coefficient of 0.999 8. The relative standard deviation of detection results was 0.11%(n=6). The added average recoveries of cimetidine in tables were in the range of 100.03%–100.58%. The cimetidine samples from different factory were detected by the method and pharmacopoeia method, the results were consistent. This method is simple,rapid, with less cimetidine sample, it can be used for the quality control of cimetidine.