Automated turbidimetric determination of cyclamate in low calorie soft drinks and sweeteners without pre-treatment

Abstract

A flow injection turbidimetric method for determination of cyclamate in low calorie soft drinks and sweeteners without pre-treatment is proposed. It was based on the oxidation of the sulphamic group of cyclamate, to sulphate by addition of nitrite. Then, a precipitate of sulphate was obtained by reaction with barium chloride, in presence of poly(vinyl alcohol) (PVA) in perchloric acid solution, at 30°C. The analytical signal was measured at 420 nm. The method presented a linear range between 0.015 and 0.120% (w/v) and the calibration graph was S = (7.792 ± 0.179) X - (0.114 ± 0.012), R2 = 0.999. A reproducibility of 5.9% was obtained from nine calibration graphs that were carried out on different days and with different conditions (standard solution, reagents solution, etc.). The detection and quantification limits were 0.006 and 0.02% (w/v), respectively, the sample throughput 45 h-1 (by considering the wash cycle and the time consuming to eliminate the clean solution from the system). The obtained results were agreement with that obtained with the standard method.