核磁共振氢谱法（~1H-NMR）测定西他沙星标准物质的含量

Quantitative determination of sitafloxacin hydrate by proton nuclear magnetic resonance（~1H-NMR）

目的建立核磁共振氢谱法测定西他沙星标准物质的绝对含量。方法采用Bruker AVANCE-500型和AVANCE-300型仪器,分别以盐酸吉西他滨和齐多夫定为内标,西他沙星中质子信号在δ8.69,δ7.76,δ3.43和δ3.14,盐酸吉西他滨质子信号在δ8.12,δ6.21和δ6.02,齐多夫定中质子信号在δ7.61和δ6.01作为定量峰,0.5 mL DMSO-d6∶氚代盐酸（DCl,44.8mg·L^-1）=4∶1为溶剂,测定条件为：探头温度303K,谱宽11.0,中心频率4.9,脉冲序列为zg 30°,延迟时间20s,采样次数32次,窗函数0.3Hz。结果在此条件下,样品与内标盐酸吉西他滨及齐多夫定的定量峰分离良好,进样精密度及重复性较好,线性范围宽,样品与内标盐酸吉西他滨和齐多夫定质量比分别在0.354 9~1.343 9和0.312 4~1.189 2范围内,其线性拟合方程分别为：Y=1.440 9X＋0.017 8（r=1.000 0,n=5）,Y=1.634 6X＋0.008 5（r=0.999 9,n=5）。结果西他沙星的含量分别为99.26%（RSD为0.06%）和99.22%（RSD为0.17%）。结论该方法准确、专属、简便、快速,适用于该药物标准物质的绝对含量测定。

Objective To establish a novel method to determine the absolute content of sitafloxacin hydrate by 1 H-nuclear magnetic resonance（1 H-NMR）.Methods The ideal spectra were obtained by Bruker AVANCE-500 and AVANCE-300 in 0.5mL solutions of DMSO-d6∶hydrochloric acid-d（DCl,44.8 mg·L^-1）=4∶1,with gemcitabine hydrochloride and zidovudine as internal standards（IS）,signals at δ8.69,δ7.76,δ3.43andδ3.14 of sitafloxacin,δ8.12,δ6.21 and δ6.02 of gemcitabine hydrochloride and δ7.61 and δ6.01 of zidovudine were selected for quantitative analysis with detection conditions as follows：the probe temperature was 303K and spectrum width（SW）was 11.0 with center frequency（O1P）at 4.9,the pulse sequence was zg 30°,delay time（d1）was 20s,number of scans（ns）was 32,and line broadening（lb）was 0.3Hz.Results The sample and internal standards i.e.gemcitabine hydrochloride and zidovudine showed good separation,high precision and repeatability.The linearity ranges with equations,Y=1.440 9 X＋0.017 8（r=1.000 0,n= 5）and Y=1.634 6 X＋0.008 5（r=0.999 9,n=5）were in the mass ratio range of 0.354 9-1.343 9and 0.312 4-1.189 2.The contents of sitafloxacin hydrate were 99.26%（RSD=0.06%）and 99.22%（RSD=0.17%）,respectively.Conclusion This method was accurate,specific,simple,and rapid and can be used for the quantitative determination of the absolute content of sitafloxacin hydrate.