Biamperometric titration and flow injection determination of cyclamate in low-calorie products

Abstract

Titration and flow injection (FI) methods with biamperometric detection at 0.7 V are proposed for determining cyclamate and are tested for various diet products. The titrant–reagent system was sodium nitrite in 1.0 mol l–1 phosphoric acid and there was no interference from glucose, fructose, sucrose, lactose, sorbitol, saccharin, benzoic acid, salicylic acid, fumaric acid, Sunset Yellow and Bordeaux-S. For the biamperometric titration method, the detection limit was 1.3 × 10–3 mol l–1 and the relative standard deviation (sr) was 1.0% for a solution containing 5.0 × 10–3 mol l–1 cyclamate (n= 9). The recovery of the sweetener from four low-calorie products ranged from 97.6 to 102.5% of the labelled amount. For the FI method there was a direct relation between cyclamate concentration and current decrease over 5.0 × 10–3 to 4.0 × 10–2 mol l–1 cyclamate with a detection limit of 2.5 × 10–3 mol l–1 and an sr of 1.7% for a solution containing 2.5 × 10–2 mol l–1 cyclamate (n= 10). Ninety results can be obtained per hour, and these, for various low-calorie products, are in good agreement with those obtained by a spectrophotometric FI method (r= 0.9993) and/or the labelled amount (r= 0.9937).