Method for the determination of radioactivity in the C-2 carbon of glycine

Abstract

A method for the determination of the radioactivity of the C-2 carbon of glycine has been developed. The method is based on the degradation of glycine (135–137 °C for 50 s) to carbon dioxide and formaldehyde using chloramine T. The formaldehyde originated from the C-2 carbon of glycine was trapped with dimedone (5,5-dimethyl-1,3-cyclohexanedione) and the formaldehyde-dimedone complex extracted with toluene. The radioactivity of the toluene was a measure of the radioactivity in the C-2 carbon of glycine. Using (2-¹⁴C)glycine, the percentage recoveries ranged from 88 to 105%, whereas with (1-¹⁴C)glycine, these were <0.5%, suggesting that the label of the C-1 carbon did not interfere with the determination of radioactivity in the C-2 carbon of glycine. The method is simple, less time consuming than existing methods and a large number of samples can be handled at a time.