微波溶解光度法测定茶叶中痕量锗

PHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF GERMANIUM IN TEA──DISSOLUTION OF SAMPLES IN MICROWAVE OVEN

采用微波加热和双层聚四氟乙烯密闭容器 ,以HNO3 HClO4 为消解试剂、MgO为外层吸收剂 ,用CCl4 萃取、光度法快速测定茶叶中痕量锗。研究了消化茶叶的最佳条件、萃取锗的最佳酸度及其它影响因素。该方法具有选择性高、成本低等特点 。

It was reported that the tea samples were rapidly dissolved in a double-layer, hermetically-sealed teflon vessel with an acid mixture of HClO 4 and HNO 3 heated in a microwave oven. In the outer wall of the vessel, some magnesium oxide was placed to absorb the residual nitric acid. The germanium in hydrochloric acid solution was separated by extraction with CCl 4, and was re-extracted with water. Finally the germanium was determined photometrically by the phenylfluorone method. The conditions for the micro-wave dissolution and for the CCl 4 extraction were optimized. The proposed method was proved to be satisfactory either in selectivity, precision and accuracy.