Simultaneous Determination of Preservatives (Sodium Benzoate and Potassium Sorbate) in Soft Drinks and Herbal Extracts Using High-Performance Liquid Chromatography (HPLC)

Chemical preservation has become an increasingly important practice in modern food technology and herbal medicinal products with the increase in production of processed and convenience products. In the present study, a reversed-phased HPLC method for simultaneous determination of the preservatives sodium benzoate (SB) and potassium sorbate (PS) is described. The separation of SB and PS were performed on the C18- column and acetonitrile – ammonium acetate buffer as mobile phase. The detector wavelength was set at 254 nm. Separation of the two components (SB and PB) was achieved in less than 6 min. Analytical characteristics of the separation such as limit of detection, limit of quantification, accuracy, precision and reproducibility were evaluated. The range of preservatives found were from not detected (nd) — 2477 mg l-1, nd — 328 mg l-1 for SB, PS respectively. In This study, has shown that the concentration of SB and PS in the soft drink samples is higher that ADI even for normal consumers, based on maximum limits specified in national standards and on model diets.