Mercaptoacetic acid, a-mercaptopropionic acid, P-mercaptopropionic acid, a $- dimercaptopropionic acid and a-mercaptolauric acid have been investigated as reagents for the identification of carbonyl compounds. A number of new derivatives have been prepared, characterized, and identified by analysis. Mercaptoacetic acid and P-mercaptopropionic acid were found to be the most generally useful reagents in this group Standard conditions ...