pH of Trisodium Citrate Solutions Stored under Customary Laboratory Conditions

DURING research on certain metallic complexes of citrate1,2, we have observed that the pH of trisodium citrate solutions depends somewhat on their ‘‘age . Solutions, prepared at various times, showed differences of as much as 1·3 pH, though raw materials, methods of preparation and concentrations were identical. In view of the widespread chemical and clinical use of such solutions, it seemed of interest to investigate this phenomenon.