91P

AN ECD-GLC TECHNIQUE FOR THE DETERMINATION OF PARACETAMOL I N HUMAN B I O F L U I D S K. Chan & M.S. H i g h l e y , School o f Pharmacy, L i v e r p o o l P o l y t e c h n i c , L i v e r p o o l L3 3AF, U.K.

Discard e t h y l l a y e r t o r e STEP 1: Plasma o r u r i n e (O.lml),water (O.Sml), 3 9 g i n t e r n a l marker, 2$1 SNNaOH,extracted w i t h 8ml-move b a s i c , and l i p i d of d i e t h y l et her s o l u b l e substances

STEP 2: Aqueous l a y e r , 2011 5NKC1, l m l phosphate b u f f e r (pH 7.4), lG(NH4)$304,extracted w i t h 2x6ml d i e t h y l ether

Evaporate organic e x t r a c t d r y n e s s by n i t r o g e n str eam

-t o

STEP 3: Add K2C03(25 ),0.1% p e n t a f l u o r o b e n z y l broEvaporate organic e x t r a c t d r y n e s s by n i t r o g e n mide i n a c e t o n e ( 0 . 5 m T t o t h e d r y r e s i d u e ; i n c u b a t e -to a t 5OoC f o r 3Omin. Cool t o room t e m p e r a t u r e str eam

STEP 4: Add w a t e r (0.5ml) t o ed w i t h n-hexane ( l m l )

I n j e c t l p l t o GLC f i t t e d w i t h ECD