SPECTROPHOTOMETRIC AND HIGH PERFORMANCE LIQUID CHROMATOGRAHIC DETERMINATION OF SODIUM BENZOATE AND POTASSIUM SORBATE IN SOME SOFT DRINKS

Ogunleye, D.T., Oyeyiola, A.O; C T Onwordi; Falana, T.G., Abolade O.M

Ogunleye, D.T., Oyeyiola, A.O Department of Chemistry, University of Lagos, Lagos, Nigeria
C T Onwordi Department of Chemistry, Lagos State University, Lagos, Nigeria
Falana, T.G., Abolade O.M Department of Chemistry, University of Lagos, Lagos, Nigeria

Keywords: Drinks, HPLC, potassium sorbate, sodium benzoate, UV-Visible spectrometry

Abstract

Sodium benzoate and potassium sorbate are preservatives commonly used in drinks and their concentration is of importance due to their health implications. This research is aimed at determining the concentration of sodium benzoate and potassium sorbate in some drinks sold in Lagos, Nigeria using high performance liquid chromatography (HPLC) and UV-visible spectrometry. Thirty samples were collected from different super markets in Lagos State and the pH, as well as the concentration of sodium benzoate and potassium sorbate were determined. A significant difference was observed between the HPLC and the UV methods at 95% confidence limit. The concentration of sodium benzoate in the different drinks analysed, ranged from ND to 1040 mg/L and that of potassium sorbate from ND to 499 mg/L. It was observed that about 40 % of the drinks were above the limit of 150 mg/L for benzoate, while 43 % were found to contain concentrations of sorbate above the permissible limits of 250 and/or 300mg/L. The acceptable daily intake (ADI) per kg of body weight of some consumers was exceeded, and this could expose the consumers to the adverse effect of continuous consumption of these drinks.