高效液相色谱-电感耦合等离子体质谱(HPLCICP-MS)法测定富硒松辽黑猪肉中硒形态研究

Determination of Selenium Species in Selenium-Enriched Songliao Black Pork by High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

摘要:

利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术建立了富硒松辽黑猪肉中硒代胱氨酸(Se-Cys₂)、甲基硒代半胱氨酸(SeMC)、硒代蛋氨酸(SeMet)、亚硒酸[Se (Ⅳ)]和硒酸[Se (Ⅵ)]5种硒形态的测定方法。添加蛋白酶E37℃水浴振荡6 h提取样品中硒形态，采用C18反相色谱柱，10 mmol/L乙酸铵+0.2 mmol/L四丁基氢氧化铵+1%甲醇(pH=5.5)为流动相，8 min内达到有效分离，方法线性范围为5~100 ng/mL，线性相关系数(r)均大于0.999，检出限为1.88、1.58、1.13、1.09、1.05 μg/L，回收率70.7%～98.4%，精密度在6%以内。利用建立的方法测定了富硒松辽黑猪肉中硒形态，其主要为硒代蛋氨酸、硒代胱氨酸和甲基硒代半胱氨酸。

Abstract:

A method for the determination of five selenium species, namely selenocystine(SeCys₂), methylselenocysteine(SeMC), selenomethionine(SeMet), selenite[Se(IV)] and selenate[Se(VI)], in selenium-enriched Songliao black pork was established by high-performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS). Selenium species in the samples were extracted with Pronase E via water bath shaking at 37℃ for 6h. Using a C18 reversed-phase chromatographic column, with the mobile phase of 10 mmol/L ammonium acetate + 0.2 mmol/L tetrabutylammonium hydroxide + 1% methanol(pH 5.5), effective separation of the five selenium species was achieved within 8 min. The linear range of the method was 5-100 ng/mL with the linear correlation coefficients(r) all greater than 0.999. The detection limits were 1.88 μg/L, 1.58 μg/L, 1.13 μg/L, 1.09 μg/L and 1.05 μg/L, respectively. The recovery rates were in the range of 70.7%-98.4%, and the relative standard deviation(RSD) was less than 6%. This established method was applied to determine the selenium species in selenium-enriched Songliao black pork, which was found to be mainly composed of SeMet, SeCys₂ and SeMC.