基于氢化物原子荧光光谱法分析富硒酿酒葡萄与酿造产物中的硒

建立了氢化物原子荧光光谱(HG-AFS)检测酿酒葡萄中总硒和无机硒的方法,并追踪分析了施用富硒叶面肥的酿酒葡萄与酿造产物中硒的含量变化。样品经HNO₃-HClO₄(4+1)180 ℃消解,盐酸100 ℃还原,HG-AFS测定总硒;样品经水提取,甲酸酸化,过Cleanert PCX小柱,消解还原,HG-AFS检测无机硒。结果表明,该方法在0.25~4 μg/L范围内线性良好(R2=0.9989),方法的检出限为2 μg/kg,定量限为5 μg/kg;总硒回收率为96.47%~97.39%,相对标准差为1.76%~5.65%;无机硒回收率为85.20%~88.91%,标准偏差为5.97%~21.45%。追踪检测显示,硒肥组酿酒葡萄总硒含量提高约3倍,含量为9.65~38.6 μg/kg;硒肥组、对照组酿酒葡萄均未检出无机硒;酿造后,酒渣、酒泥和成品酒中硒存留分数分别为89.3%、8.7%和2.0%。施富硒叶面肥可显著提高酿酒葡萄的硒含量,达到富硒食品标准,但酿造后硒主要随酒渣、酒泥流失,仅少量留存在葡萄酒中。

Analysis of Selenium Contents in Selenium-rich Wine Grape and the Vinification Products Based on Hydride Generation Atomic Fluorescence Spectrometry

A new method was established for the determination of total selenium and inorganic selenium in wine grapes by hydride atomic fluorescence spectrometry(HG-AFS)and the changes of selenium contents were traced and analyzed in the wine grapes applied selenium-enriched foliar fertilizer and its vinification products. The sample was digested with HNO3-HClO4(4+1)at 180 ℃,reduced with hydrochloric acid at 100 ℃,and then the total selenium was determined by HG-AFS. The sample was extracted with water,acidified,passed through Cleanert PCX cartridge,digested and reduced,and then the inorganic selenium was determined with the same way. Results showed that a good linearity(0.25~4 μg/L)was obtained with R2 value of 0.9989;the detection limit was 2 μg/kg. The limit of quantification was 5 μg/kg. The recoveries of total selenium were 96.47%~97.39% and relative standard deviations were 1.76%~5.65%. The recoveries of inorganic selenium were 85.20%~88.91% and the standard deviations were 5.97%~21.45%. The tracing test showed that the total selenium content in the wine grapes applied selenium fertilizer increased 3 times with the content of 9.65~38.6 μg/kg by contrasting to the controls. The inorganic selenium was detected in neither wine grapes tested nor controls. After vinification,the selenium fraction in the wine residues,lees and wine,were 89.3%,8.7% and 2.0% respectively. Through applying selenium foliar fertilizer,the selenium in wine grapes significantly increased to the value required by criterion of selenium-enriched food. However,selenium was mainly lost with the separation of wine residue and lees during vinification,and only a small amount remained in the wine.