3种前处理-HPLC法测定婴幼儿配方食品中维生素B1

分别采用国标法(GB 5009.84-2016)、酸解法和等电点法处理试样,用高效液相色谱-荧光检测(HPLCFLD)法测定婴幼儿配方乳粉和婴幼儿谷类辅助食品中的维生素B1。结果表明,维生素B1在3.036~303.6 ng/mL范围内线性良好,相关系数R^2>0.999。3种方法的回收率和相对标准偏差(RSD,n=6)均符合要求。其中,国标法和酸解法的RSD值相对较小,等电点法的RSD值偏大。试样经国标法、酸解法处理测得维生素B1含量与标签一致,少数试样经等电点法处理测得维生素B1含量明显偏低。酸解法相较于国标法,省去了耗时最长的酶解步骤,仍获得良好回收率。可见,酸解法前处理简单,耗时短,结果准确度高,重现性好,适用于批量检测,总体优于国标法和等电点法。

Comparative Study on 3 Pretreatment Methods for HPLC Determination of Vitamin B1 in Formula Foods for Infants and Young Children

Three pretreatment methods,including national standard method(GB 5009.84-2016),acid hydrolysis method and isoelectric point method,for high performance liquid chromatography-fluorescence detection(HPLC-FLD)were applied to determination of vitamin B1 in formula milk powder and cereal-based complementary foods for infants and young children.The results showed that good linear relation was presented in the range of 3.036-303.6 ng/mL for vitamin B1 with the correlation coefficients R^2>0.999.Recovery and relative standard deviation(RSD,n=6)of the three methods all conformed to the requirement,among which the RSD value of national standard method and acid hydrolysis method was smaller than that of isoelectric point method.The content of vitamin B1 in the sample was consistent with the label by national standard method and acid hydrolysis method,while which was found to be obviously low in a few samples by isoelectric point method.Compared with the national standard method,the acid hydrolysis method omitted the time-consuming enzymatic hydrolysis step and still obtained a good recovery rate.It can be seen that the acid hydrolysis method is suitable for batch detection for its simple,quick,high in accuracy and reproducibility,and generally superior to the national standard method and isoelectric point method.