本文研究了利用 19F- NMR技术测定盐酸左氧氟沙星药物样品中氟的检测条件。优化了实验参数 ,选用三氟乙酸钠作内标 ,重水与去离子水混合液为溶剂。测定了对盐酸左氧氟沙星样品中氟含量。实验表明 ,氟的加标回收率在 98.4 %— 10 0 .6 %之间 ,标准偏差为 0 .0 0 2 14 %— 0 .0 4 89% ,相对标准偏差小于1.12 4 %。 In this paper, the determination of fluorine in the levofloxacin hydrochloride drug samples by 19F-NMR was studied. Optimization of the experimental parameters, the choice of sodium trifluoroacetate as internal standard, heavy water and deionized water mixture as solvent. The fluorine content of levofloxacin hydrochloride samples was determined. The experimental results showed that the spiked recoveries of fluorine ranged from 98.4% to 10.06% with a standard deviation of 0.00214% to 0.04989 and a relative standard deviation of less than 1.12 4%.