Precipitation flow-injection method for the determination of saccharin in mixtures of sweeteners

An atomic absorption spectrometric method for the determination of sodium saccharin in commercially available mixtures of artificial sweeteners and pharmaceuticals by continuous precipitation with silver ion in a flow manifold is proposed. The silver saccharinate precipitate formed is retained on a filter, washed with diluted acetic acid and dissolved in ammonia for on-line atomic absorption determination of silver, the amount of which in the precipitate is proportional to that of saccharin in the sample. The proposed method allows the determination of sodium saccharin in the range 5–75 μg ml−1 with a relative standard deviation of 2.7% at a rate of ca. 20 samples h−1. The method is very selective; other sweeteners do not interfere, but chloride must be absent.