Picogram analysis of free triiodothyronine and free thyroxine hormones in serum by equilibrium dialysis and electron capture gas chromatography.
A methodology involving equilibrium dialysis and gas chromatography has been developed to measure concurrently the concentration of the dialyzable (i.e., free) fractions of thyroxine and 3,5,3'-triiodothyronine in serum. The electron capture response of the N,0-diheptafluorobutyryl methyl ester derivatives of these hormones allows their detection and quantitation in the picogram range (detection limit approx. 0.2pg). Purification of the dialysate is achieved using a cation-exchange column which is pretreated with diiodothyronine. Adsorption problems on the glassware are eliminated by silanization. The methodology also resolves 3,3',5'-triiodothyronine (reverse T3).
D000327:Adsorption; D002849:Chromatography, Gas / Q000379:methods*; D002852:Chromatography, Ion Exchange; D003956:Dialysis / Q000379:methods*; D006801:Humans; D008832:Microchemistry; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
D014284:Triiodothyronine; D013974:Thyroxine