B.J. Liska

Improved extraction procedure for 2,3,5-triiodobenzoic acid from milk and milk products

Whs s tudys 2 , 3 , 5 t r s 1 6 3 a c i d (TIBA) r e s t d u e s i n mi lk and mi lk p r o d u c t s u s ing sas chromatography 87 i t became n e c e s s a r y t o deve lop an e x t r a c t i o n and c l e a n u p p r o c e d u r e whs would c o n c e n t r a t e TIBA a n d / o r 8 m e t a b o l s s e p a r a t e Che compound from i n t e r f e r • n g mi lk c o n s t i t u e n t s , and g i v e a low backSround s i g n a l . Th i s was n e c e s s s s i n c e most e x t r a c t s solvents were round fo form emulsions w 8 milk or milk products ( e t h e r , me thano l , eChanol , i s o p r o p y l a l c o h o l , and aqueous fo rmic acld) or were expenslve (acetonitr 8 The earlier extraction method as used by L i sk (1) does noC i n c l u d e a c l e a n u p p r o c e d u r e . P,,rocedure s C l ean -up and E x t r a c t i o n P r o c e d u r e . M 8 o r mi lk p r o d u c t s ~ p l e s we 8 100 g. were p l a c e d i n a t a r e d 500 ml. e r l en m ey e r f l a s k on a magne t 8 s t i r r e r and t i t r a t e d dropwise w i th ~ P O 4 (85~-N.u untll the mixCure was at a pli of 2.5-3.0 (about 4 ml. per I00 S. samp1e). A minimum of 250 ml. of technlcal stade a c e t o n e was added and che m i x t u r e a l lowed to s t s f o r 60 m i n u t e s . The r e s u l t 8 s l u r r y was s e c c l e d i n an i c e b a t h f o r about 1 hour ( speeds f i l t r a t i o n ) and t hen f i l c e r e d w 8 vacuum on a 150 C s c i n t e r e d g l a s s f u n n e l . Acetone was e v a p o r a t e d from che f i l t e r e d