Gas chromatography of the trimethylsilyl derivatives of iodotyrosines and iodothyronines

✍ Scribed by Nicholas M. Alexander; Robert Scheig

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 449 KB
• Volume: 22
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(68)90306-0

✦ Synopsis

After silylation,* some nonvolatile biological compounds are converted to volatile derivatives that can be analyzed by gas chromatographic separation techniques. Notable success has been achieved with carbohydrates, in which silylation proceeds quickly with a mixture of hexamethyldisilazane and trimethylchlorosilane in pyridine (1). Certain volatile amino acid derivatives have also been obtained with these silylating agents (2-5) as well as with N-trialkylsilyl amines (6, 7)) but the yields were variable, the reaction times were prolonged, and elevated reaction temperatures were required.

These difficulties have recently been overcome by the silylating agent BSA,S which apparently reacted quantitatively with all the common amino acids (including DIT) in 10 to 30 min (8). The silylated amino acids, except arginine, yielded single peaks when analyzed by gas chromatography. Because of its speed and sensitivity, it appeared desirable to extend this method to the iodoamino acids, especially TB and T4. This report describes the gas chromatographic separation of the trimethvlsilvl derivatives of tyrosine, T, MIT, DIT, T,, and T,.