烟酸片样品用吡啶超声提取、分离后,所得上清液中的烟酸与六甲基二硅氨烷和三甲基氯硅烷进行衍生化反应,产物用正庚烷萃取.萃取液加入苯甲酸乙酯作为内标,供气相色谱-质谱分析.在气相色谱分离中用HP-5MS毛细管柱(30m×250 μm,0.1 μm)为固定相,在质谱测定中采用全扫描模式.烟酸标准与内标峰面积的比值与烟酸的质量浓度在1.000 g·L-1范围以内呈线性关系,检出限(3s)为4.54 mg·L-1.方法用于烟酸片剂中烟酸的测定,相对标准偏差(n=6)为1.65%~2.89%,回收率在90.1%~93.2%之间.

Sample of nicotinic acid tablet was ultrasonically extracted with pyridine and after filtration nicotinic acid in the supernatant was derivatized with hexamethyldisilazane and trimethylchlorosilane.The derivatized product was extracted with n-heptane.The extract was used for GC-MS analysis after adding ethyl benzoate as internal standard.The HP-5MS capillary column was used for GC separation and the full-scanning mode was adopted in MS determination.Linear relationship between values of peak area ratios of the nicotinic acid standard to internal standard and mass concentration of nicotinic acid was obtained in the range within 1.000 g·L-1,with detection limit (3s) of 4.54 mg·L-1.The proposed method was applied to the analysis of nicotinic acid tablets,giving values of RSD′s (n=6) in the range of 1.65%-2.89% and recovery in the range of 90.1%-93.2%.