高效液相色谱-电感耦合等离子体质谱法测定富硒蛋白多糖中纳米单质硒含量

摘要

This experiment was conducted to establish a novel method which could efficiently,accurately and quickly determine the nano elemental selenium (Nano-Se) content extracted from selenium-enriched polysaccharides.Approximately 3 mg of protease Ⅹ Ⅳ was added into 3 mL of H2O contained 25 mg selenium-enriched polysaccharides which produced by Enterobacter cloacae Z0206,and the resulting mixture was mainmined at 37 ℃ in an ultrasonic bath for 30 min.After centrifugation,the precipitate (Nano-Se) was oxidized by HC1-H2O2 system at room temperature.Then the consequent solution was directly analyzed by high performance liquid chromatography coupled with inductivity coupled plasma mass spectrometry (HPLC-ICP-MS) (equipped with PRP-X100 anion column and the mobile phase was 5 mmol/L citric acid with a pH of 4.5) and the content of Nano-Se was 2 439 μg/g.As a contrast,the same samples were oxidized by HNO3-HC1O4 system and determined by the method described in GB/T 13883-2008 using hydride generation atomic fluorescence spectrometry (HG-AFS) and the content of Nano-Se was 2 450 μg/g which was similar to the result above.Compare with the method described in GB/T 13883-2008,the oxidation system in the current method is much milder and faster and easy to control which is suitable for Nano-Se detection.%本试验旨在建立高效、准确、快速测定富硒蛋白多糖中纳米单质硒含量的方法.将25 mg阴沟肠杆菌(Enterobacter cloacae)Z0206产富硒蛋白多糖样品悬浮在3mL蒸馏水中,在3mg XⅣ型蛋白酶作用下超声处理30 min(37℃),将酶解液离心得到的沉淀物(纳米单质硒)在常温下经双氧水-盐酸(H2O2-HC1)体系消解,所得溶液直接经高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析[以PRP X100阴离子色谱柱对样品中的亚硒根离子(SeO2-)进行分离,流动相组成为5 mmol/L柠檬酸水溶液(pH 4.5)],测得样品中纳米单质硒含量为2 439 μg/g.以国家标准(GB/T 13883-2008)方法[样品以硝酸-高氯酸(HNO3-HC1O4)体系消解处理,经氢化物发生-原子荧光(HG-AFS)分析]为对照,测得样品中纳米单质硒含量为2 450 μg/g.2种方法的测定结果高度一致.与GB/T 13883-2008中描述的方法相比,采用本试验建立的氧化体系条件更温和、快速并且易于控制,适用于纳米单质硒的快速检测.