ABSTRACT
Y o s h i m u r a et al [1] have descr ibed a h i g h l y sensi t ive m e t h o d for preconcent ra t ing borate based o n a d s o r p t i o n o n Sephadex G - 2 5 g e l i n a lka l ine m e d i u m a n d revers ible d e s o r p t i o n i n a c i d m e d i u m . T h e borate is then d e t e r m i n e d spec t ropho tomet r i ca l ly b y the azometh ine-4-method .
