Carbon-11-labeled p a l m i t i c a c i d i s produced r o u t i n e l y a t Washington U n i v e r s i t y School of Medicine f o r s t u d i e s o f m y x a r d i a l netabolism. To accomodate t h e needs o f 8 -15 p r e p a r a t i o n s per week and t h e l a r g e amounts o f r a d i o a c t i v i t y (>20 m l i l s t u d y ) r e q u i r e d , a r e m o t e l y -c o n t r o l l e d system f o r t h e p r e p a r a t i o n o f L1-llClpalmitic a c i d has been constructed. The system i s small (0.04 m3), c o m p l e t e l y p o r t a b l e and contained t o t a l l y w i t h i n a small lead-shielded hood. Large q u a n t i t i e s o f C -1 1 p a l m i t i c a c i d (up t o 675 mCi) have been prepared, w i t h minimum r a d i a t i o n exposure t o t h e operator. system has been i n f u l l o p e r a t i o n f o r two years, and has been used f o r more than 200 syntheses w i t h a f a i l u r e r a t e o f l e s s than 5%. This INTRODUCTION The Cardiovascular D i v i s i o n o f t h e Washington U n i v e r s i t y School o f Medicine r e q u i r e s m u l t i p l e p r e p a r a t i o n s per week o f [l-llClpalmitic a c i d as a d i a g n o s t i c agent f o r myocardial metabolism i n p a t i e n t s ( 1 ) and animal models ( 2 ) . Although C l -1 1 C l p a l m i t i c a c i d i s e a s i l y synthesized b y t h e r e a c t i o n o f carbon-11 carbon d i o x i d e w i t h pentadecyl magnesium bromide, t h e a c t u a l p r e p a r a t i o n f o r i n v i v o s t u d i e s e n t a i l s several a d d i t i o n a l steps o f i s o l a t i o n , b i n d i n g o f t h e l a b e l e d f a t t y a c i d t o hurnan serum albumin, and s t e r i l i z a t i o n v i a E l i l l i p o r e f i l t r a t i o n . The p r e p a r a t i o n of l l c -p a l m i t i c a c i d has f o r many years been done manually (3), b u t t h e r a d i a t i o n dose t o t h e chemist i s appreciable. C1-11Clpalmitic a c i d has prompted t h e development o f a remote system f o r synthesis o f t h i s radiopharmaceutical. Previous d e s c r i p t i o n s o f "remote" p a l m i t i c a c i d systems are e i t h e r incomplete (4), n e g l e c t t o describe t h e s h i e l d i n g necessary (4,5), o r are unnecessarily complex and i n v o l v i n g a m u l t i p l e vessel synthesis ( 5 ) . We d e s c r i b e here t h e c o n s t r u c t i o n and
o p e r a t i o n of a t o t a l l y remote system, u t i l i z i n g a s i n g l e r e a c t i o n vessel,