A method of 1H qNMR was developed for the determination of sildenafil citrate,tadalafil and vardenafil added in dietary supplements illegally.In this experiment,Bruker Avance DRX 500 was applied,with deuterated dimethylsulfoxide (DMSO-d6) as solvent and 2,3,5-triiodobenzoic acid as internal standard substance.The spectral width,center frequency,pulse width,relaxation delay and the number of scans were optimized,and the method was validated.The results showed that,the correlation coefficients for the linear regression were not less than 0.999.The detection limits of the method for sildenafil citrate,tadalafil and vardenafil were 0.045,0.026,0.033 mg/ mL,and the quantitation limits were 0.218,0.128,0.159 mg/mL,respectively.The inter-day RSDs were 0.38％,0.85％,0.34％,and the intra-day RSDs were 0.72％,1.2％,1.4％,respectively.The accuracy of the method was also verified by comparing the results of 1H qNMR and HPLC-DAD,testing the same 13 samples.The results showed that the RSDs of two methods were between 1％ and 8％.%建立了保健食品中枸橼酸西地那非、他达拉非、伐地那非的核磁共振氢谱定量(1H qNMR)分析方法.采用布鲁克Avance DRX 500超导核磁共振波谱仪,以氘代二甲亚砜为溶剂,2,3,5-三碘苯甲酸为内标物,优化了仪器采集参数,并进行了方法验证.结果表明:当内标添加量为2 mg、内标与待测化合物摩尔比在1∶0.1～1∶1.2范围时,标准曲线线性良好,相关系数(r2)不小于0.999;枸橼酸西地那非、他达拉非、伐地那非的检出限分别为0.045,0.026,0.033 mg/mL,定量下限分别为0.218,0.128,0.159 mg/mL;日内精密度RSD值分别为0.38％,0.85％,0.34％;日间精密度RSD值分别为0.72％,1.2％,1.4％.利用所建立的方法对13种实际样品进行定量分析;并将测试结果与HPLC-DAD法测试结果进行比较,两种测试结果的RSD在1％～8％之间.
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