Sulpholane as a solvent for titration of barbiturates and sulpha drugs.

Sulpholane (tetramethylenesulphone) has been used as the medium for non-aqueous potentiometric titration of barbiturates and sulpha drugs with tetrabutylammonium hydroxide. Recoveries for 0.1-0.3 mmole of barbituric acid, phenobarbital, amobarbital, barbital, secobarbital, sulphapyridine, sulphadiazine and sulphamerazine were generally in the range 99-101%. A glass-calomel electrode system was used: common acid-base indicators give no colour change in the medium used.