ABSTRACT

Preconcent ra t ion techniques b y thei r na ture in t roduce a n a d d i t i o n a l step in to ana ly t i ca l p rocedures for trace ana lys i s of wa te r samples .

Q u i t e an apprec iab le a m o u n t of effort has recent ly been p u t in to d e v e l o p i n g on-l ine preconcent ra t ion procedures . A s w e l l as s p e e d i n g u p the ana lys is s u c h m e t h o d s increase the ou tpu t a n d decrease ana ly t i ca l t ime a n d i n t roduce the pos s ib i l i t y of una t t ended ove rn igh t opera t ion .