反相高效液相色谱法测定保健品中反式维生素K1的含量

Determination of Trans-Vitamin K in Health Products by Reversed Phase High Performance Liquid Chromatography

建立了反相高效液相色谱法测定保健品中维生素K1反式构体含量的方法。将维生素K1补充片剂研磨成粉后,称取0.25 g样品,用异丙醇溶解后,定容至50 mL棕色容量瓶中,用0.45μm滤膜过滤,取上清液,采用Phenyl柱,以不同体积比的甲醇和50 mmol·L^(-1)乙酸溶液的混合液为流动相进行梯度洗脱。结果显示:在上述色谱条件下,顺、反式维生素K1的分离度(RS)为1.76,线性范围分别为0.01~2 mg·L^(-1)和0.04~8 mg·L^(-1),检出限(3S/N)分别为0.032 mg·L^(-1)和0.074 mg·L^(-1)。对空白样品进行3个浓度水平的加标回收试验,反式维生素K1的回收率为92.0%~95.2%,测定值的日内相对标准偏差(RSD,n=6)为1.6%~2.2%,日间RSD(n=5)为2.4%~4.8%;顺式维生素K1的回收率为90.0%~101%,测定值的日内RSD(n=6)为1.4%~2.3%,日间RSD(n=5)为2.6%~4.6%。方法用于实际样品分析,反式维生素K1的检出量为75.36~80.12μg·g-1。

A method of reversed phase high performance liquid chromatography for the determination of trans-vitamin K1 in health products was established.The sample(0.25 g)was weighted after grinding the vitamin K1 supplement tablets into powder,and then dissolved and made its volume up to 50 mL brown volumetric flask by isopropanol.The supernatant was filtered by a 0.45μm filter membrane and separated on a Phenyl column with the mixtures of methanol and 50 mmol·L^(-1)acetic acid solution at different volume ratios as mobile phase for gradient elution.The results showed that under the above chromatographic conditions,the resolution(RS)of cis-and trans-vitamin K1 was 1.76,linearity ranges were 0.01-2 mg·L^(-1)and 0.04-8 mg·L^(-1),with detection limits(3 S/N)of 0.032 mg·L^(-1)and 0.074 mg·L^(-1),respectively.Recovery test was made by adding standard solution on blank samples at 3 concentration levels,giving values of recovery of trans-vitamin K1 and cis-vitamin K1 in the ranges of 92.0%-95.2%and 90.0%-101%,and intra-day RSDs(n=6)of the determined values were in the ranges of 1.6%-2.2%for trans-vitamin K1 and 1.4%-2.3%for cis-vitamin K1.The inter-day RSDs(n=5)of the determined values ranged from 2.4%to 4.8%for trans-vitamin K1 and from 2.6%to 4.6%for cis-vitamin K1.The proposed method was used for the analysis of actual samples,and the detection amount of trans-vitamin K1 was in the range of 75.36-80.12μg·g-1.