subsequent resolution of each fraction into lithocholate , deoxycholate , chenodeoxycholate , ursodeoxycholate and cholate was attained by gc on a cross-linked 5 % phenylmethyl silicone fused-silica capillary column where bile acids were monitored with a characteristic carboxylate anion [ m - 181 ] -in the nici mode using isobutane as a reagent gas .
C0003075
anion
C0022023
nici