高效液相色谱-电感耦合等离子体质谱法测定十字花科植物中5种不同形态硒的含量

Determination of Different Selenium Speciation in 5 Kinds of Cruciferous Plants by HPLC-ICP-MS

目的:建立十字花科植物中硒代胱氨酸(SeCys_(2))、甲基硒代半胱氨酸(MeSeCys)、4价硒[Se(IV)]、硒代蛋氨酸(SeMet)、6价硒[Se(VI)]5种硒形态的高效液相色谱-电感耦合等离子体质谱(High performance liquid chromatography-inductively coupled plasma-mass spectrometry,HPLC-ICP-MS)的分析方法,并考察了5种十字花科植物对不同硒形态的富集能力。方法:采用超声辅助蛋白酶E及纤维素酶提取样品,使用HamiltonPRP-X100为色谱分离柱,以(NH_(4))_(2)HPO_(4)为流动相,对堇叶碎米荠、甘蓝、西蓝花、油菜、萝卜叶中5种不同形态硒进行HPLC分离,利用ICP-MS定量检测。结果:5种不同形态硒在18 min内实现基线分离,在0~200μg/L浓度范围内线性良好,相关系数r>0.999,SeCys_(2)、MeSeCys、Se(IV)、SeMet、Se(VI)检出限分别为0.005、0.025、0.005、0.010、0.025 mg/kg,相对标准偏差分别为2.4%、3.1%、1.6%、3.3%、2.1%,回收率在可接受范围内(79.3%~103.5%)。5种十字花科植物中硒形态及含量存在明显差异,甘蓝中SeCys_(2)、SeMet、Se(VI)含量较高,而MeSeCys检出率相对较低;堇叶碎米荠中SeCys_(2)、SeMet含量较高;萝卜叶中5种硒形态均有检出,但含量相对较低,其中SeCys_(2)略高;西蓝花中SeCys_(2)、SeMet、Se(VI)形态均有检出,其中SeMet、Se(VI)含量相对最高;油菜中主要检出SeCys_(2)和SeMet,且含量较高。结论:所建立的方法适用于测定十字花科植物中不同硒形态的含量,其操作较为简便、线性范围宽、灵敏度高,能满足检测需要。十字花科植物对硒元素的聚集能力较强,其中SeCys_(2)、SeMet、Se(VI)检出率较高,且不同十字花科植物对不同形态硒的富集能力存在明显差异。

Objective:To establish a high performance liquid chromatography-inductively coupled plasma-mass spectrometry(HPLC-ICP-MS)method in the determination of five selenium species,including selenocystine(SeCys_(2)),methylselenocysteine(MeSeCys),tetravalent selenium(Se(IV)),selenomethionine(SeMet),and hexavalent selenium(Se(VI))in cruciferous plants and to investigate the enrichment capacities of these selenium species in five different cruciferous plants.Methods:The samples were extracted with ultrasound-assisted protein E and cellulase.Separation was performed using a Hamilton PRP-X100 column with(NH_(4))_(2)HPO_(4)as the mobile phase.The separation of five selenium species in Cardamine violifolia,cabbage,broccoli,oilseed rape,and radish leaves was achieved by HPLC,and quantification was conducted using ICP-MS.Results:Different selenium speciation was separated in 18 min,showed a good linear relationship between 0 to 200μg/L,correlation coefficients were both greater than 0.999.Detection(LOD)of SeCys_(2),MeSeCys,Se(IV),SeMet,Se(VI)were 0.005,0.025,0.005,0.010,0.025 mg/kg,with relative standard deviations(RSD)of 2.4%,3.1%,1.6%,3.3%,and 2.1%.Recovery rates were within the acceptable range from 79.3%to 103.5%.Significant differences were found in selenium species and content among the five cruciferous plants.In cabbage,SeCys_(2),SeMet,and Se(VI)had higher contents,while MeSeCys showed relatively low detection.In Cardamine violifolia,SeCys_(2)and SeMet contents were higher.All five selenium species were detected in radish leaves,but their contents were relatively low,with SeCys_(2)being slightly higher.In broccoli,SeCys_(2),SeMet,and Se(VI)were detected,with SeMet and Se(VI)having the highest contents.In oilseed rape,SeCys_(2)and SeMet were mainly detected,with higher contents.Conclusion:The established method is suitable for determining different selenium species in cruciferous plants,offering simplicity,a wide linear range,and high sensitivity.Cruciferous plants show a strong ability to accumulate selenium,with higher detection rates of SeCys_(2),SeMet,and Se(VI).However,the enrichment ability of different cruciferous plants for different selenium species varies significantly.