Validation of an HPLC-DAD/UV method for the quantification of cyclamate in tabletop sweeteners: risk of exceeding the acceptable daily intake

Cyclamate is widely used as intense sweetener in the European Union. The absence of a maximum limit for the use of cyclamate in tabletop sweeteners and the growing demand for this type of product highlights the importance of developing robust analytical methods for the determination of its content to understand if the consumption of tabletop sweeteners can have a negative impact on human health. The present work aimed at the optimisation and validation of an high-performance liquid chromatography (HPLC) analytical method for cyclamate determination in tabletop sweeteners based on the procedure of European Standard EN 12857. The validated method was then applied to the determination of this sweetener in different types of tabletop sweeteners (liquid, powder and tablets). Both standards and samples solutions were submitted to a derivatisation procedure which converted cyclamate to N,N-dichlorocyclohexylamine. The derivatised product was separated and quantified using a reversed-phase column, a mobile phase composed of water (20%) and methanol (80%), isocratic flow of 1 ml min-1, and detection by ultraviolet spectrophotometry at a wavelength of 314 nm. The analytical method was internally validated according to the following validation parameters: working range, linearity, limits of detection and quantification, sensitivity, precision (repeatability and intermediate precision), and uncertainty. This method proved to be specific and selective for the determination of this sweetener, showing repeatability, RSDr ≤ 3%, intermediate precision, RSDR ≤ 3.3%, and recovery rates from 92% to 108% for the different tabletop sweeteners. The method uncertainty was 9.4%. The concentration of cyclamate in the samples varied significantly, from 2.9% to 73.9%, which demonstrated that a possible excessive consumption of one of the analysed sweeteners can lead to exceeding the acceptable daily intake for cyclamate.