Single-point titrations: Part 4. Determination of acids and bases with flow injection analysis

A single-point titrimetric system for acids and bases based on the flow injection principle is reported. The sample (30 μl) is introduced into a water stream with a pneumatic injector; this stream reacts with a linear acidic or basic buffer solution in a merging stream, and the peak height is recorded potentiometrically with a glass electrode in a flowthrough cell. The peak maxima are a linear function of the acid or base concentration in the range 0.01–0.1 M. At a sampling rate of 180 samples per hour, the relative standard deviation is less than 1%. The method can be used at sampling rates as high as 720 samples per hour.