摘要
取0.1 g脱脂后富硒大豆样品于离心管中,用5 mL pH 7.5的130 mmol·L^(-1)三(羟甲基)氨基甲烷-盐酸缓冲液超声振荡30 min,用15 mg链霉蛋白酶于37℃振荡酶解5 h,离心后取上清液,过0.22μm尼龙有机滤膜。滤液中的硒代半胱氨酸(SeCys)、硒代蛋氨酸(SeMet)、甲基硒代半胱氨酸(MeSeCys)在Agela MP-C_(18)色谱柱上分离,以含2%(体积分数)甲醇和0.5 mmol·L^(-1)四丁基溴化铵的40 mmol·L^(-1)磷酸氢二铵溶液(pH 7.0)进行等度洗脱,并采用氢化物发生-原子荧光光谱法测定3种硒代氨基酸的含量。结果表明,3种硒代氨基酸在7 min内可以实现基线分离,标准曲线的线性范围均为5~100μg·L^(-1),检出限依次为0.086,0.075,0.047 mg·kg^(-1)。按照标准加入法进行回收试验,回收率为85.5%~103%,测定值的相对标准偏差(n=7)不大于3.0%。方法用于分析富硒大豆中的硒代氨基酸,大豆中硒赋存形态多为SeMet,含量占总硒量的85.5%~94.5%。
0.1 g of defatted selenium-enriched soybean sample was taken into a centrifuge tube,and the sample was ultrasonicated with 5 mL of 130 mmol·L^(-1) tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution at pH 7.5 for 30 min,then enzymatically hydrolyzed with 15 mg of pronase for 5 h at 37℃,and centrifuged to take the supernatant,which was passed through 0.22μm nylon organic filter membrane.Selenocysteine(SeCys),selenomethionine(SeMet),and methylselenocysteine(MeSeCys)in the filtrate were separated on Agela MP-C_(18) column,and eluted isocratically with 40 mmol·L^(-1) ammonium hydrogen phosphate solution(pH 7.0)containing 2%(volume fraction)methanol and 0.5 mmol·L^(-1) tetrabutylammonium bromide.The three selenoamino acids were determined by hydride generation atomic fluorescence spectrometry.As shown by the results,the baseline separation of the three selenoamino acids could be achieved within 7 min,and the linear ranges of the standard curves were all 5-100μg·L^(-1),with detection limits of 0.086,0.075,and 0.047 mg·kg-1 respectively.The recoveries of the three selenoamino acids according to the standard addition method were in the range of 85.5%-103%,and RSDs of the determined values(n=7)were not greater than 3.0%.This method was applied to analysis of the selenoamino acids in selenium-enriched soybeans,and the selenium fugitive form in soybeans was mostly SeMet,which accounted for 85.5%-94.5%of the total selenium.
作者
卢鑫
张琳
王铁良
周晓华
LU Xin;ZHANG Lin;WANG Tieliang;ZHOU Xiaohua(School of Medicine and Nursing,Jiyuan Vocational and Technical College,Jiyuan 459000,China;Institute of Agricultural Quality Standards and Testing Technology,Henan Academy of Agricultural Sciences,Zhengzhou 450002,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2024年第3期288-293,共6页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
河南省高等学校重点科研项目计划(21B150014)。
