Modification of a constant flow buret

Abstract

A recent article in this Journal1 described a constant flow buret, which we found to be very reliable. A common reagent used in this system is a strong base such as NaOH. The normality of a standardized NaOH solution is subject to change as a result of reaction with CO2 in the air. The exposure of the titrant to the air in the funnel of the original apparatus limits the use of the apparatus to very short periods.The design shown replaces the open funnel with a polypropylene beaker fitted with a large rubber stopper. The stopper was bored to accept the two tubes as shown in the original apparatus.