Migration of Inorganic Antimony into Polyethylene Terephthalate Bottled Water Marketed in the Greater Accra Region of Ghana

Abstract

The migration of inorganic antimony from polyethylene terephthalate plastic bottles into waters stored in them was investigated using hydride generation atomic absorption spectrophotometry. Six popular brands of bottled water marketed in the greater Accra region of Ghana were used. These were held under various storage conditions and their dissolved Sb monitored over a period. In addition, the Sb in the plastic containers and some physicochemical properties of the waters were determined. The determined Sb in the plastic containers revealed amounts ranging from 123.46 to 146.45mg/kg. The determined physicochemical properties were pH (6.78-7.43); Ca²⁺ (1.61-12.39mg/L); Mg²⁺ (1.00-4.96mg/L); HCO₃⁻ (6.18-55.41mg/L); and total dissolved solids (8.70-70.40mg/L). Differences in the residual amounts of Sb showed dissimilarities existed in the quality of the plastics used in packaging. The physicochemical properties were seen to have no effect on migration. Sb levels in the water stored in the plastic containers were observed to increase with time under all the storage conditions for all the brands of plastic bottled water. The plastic bottled waters were, however, found not to have Sb exceeding the world health organisation maximum contaminant level within the period taking into consideration the specified limited time of expiry.

Keywords: Migration; physicochemical properties; plastic bottles; spectrophotometry; storage conditions.