Amino-acid contamination of aqueous hydrochloric acid.

SIDLE1,2 has drawn attention to the contamination of aqueous HCl, both undistilled and distilled, by amino-acids. This is an important problem, for example, when HCl is used to hydrolyse material such as lunar and meteorite samples which contain very small concentrations of amino-acids and peptides. We have obtained data on the amino-acid contamination of distilled constant boiling HCl which we believe to be due to the volatility of the amino-acids in aqueous hydrochloric acid.