ABSTRACT
Lee [1] preconcent ra ted m e t h y l - a n d e t h y l - m e r c u r y i n s u b - n a n o g r a m amoun t s f r o m n o n sal ine waters o n to s u l p h y d r y l cot ton fibre. S u l p h y d r y l cot ton fibre w a s p repa red b y s o a k i n g cot ton for 4 to 5 d i n a m i x t u r e of t h iog lyco l i c a c i d , acetic a n h y d r i d e , acetic ac id , s u l p h u r i c a c i d , a n d wa te r at 40 to 45°C . A d s o r b e d m e r c u r y c o m p o u n d s were e lu t ed f rom the co t ton f ibre w i t h h y d r o c h l o r i c a c i d / s o d i u m c h l o r i d e a n d ex t r ac t ed w i t h benzene. U s i n g gas c h r o m a t o g r a p h y w i t h e lectron capture detect ion, the detect ion l i m i t s were 0.04ng L 1 u s i n g a 2 0 L sample v o l u m e . P rec i s i on was a p p r o x i m a t e l y 20%. The m e t h o d w a s a p p l i e d to s n o w a n d freshwater samples of v a r y i n g h u m i c ac id content. M e t h y l m e r c u r y concentra t ions v a r i e d b e t w e e n 0.09 a n d 0 .22ng L ~ l , a n d recover ies of s p i k e d m e t h y l m e r c u r y v a r i e d be tween 42 a n d 68% a n d were s t rong ly corre la ted w i t h the c o n c e n t r a t i o n of h u m i c substances . M e t h y l m e r c u r y concent ra t ion i n s n o w was 0.28ng L 1 a n d the recovery w a s 79%.
