Tubeless Gastric Analysis by Use of Insoluble Salts with Exogenous Ions. ∗

Summary

1. The rationale of the use of insoluble salts with special exogenous indicator ions to determine gastric acidity without intubation has been described. 2. Theoretical consideration and in vitro and in vivo experiments have demonstrated that by determining the amount of quinine in the first 2-hour urine excretion after the oral administration of 320 mg of quinine carbonate, the presence of free hydrochloric acid from a low to a normal or higher range or its absence can be estimated without subjecting the individual to intubation. 3. Further experimentation with larger doses of quinine carbonate, if tolerated, or with comparable insoluble salts with various exogenous indicator ions, may make it possible to differentiate approximately between normal and high gastric hydrochloric acid secretion without intubation.