keywords: Keana, iodine, rock salt, potassium iodate, physicochemical parameters, phenolphthalein.
This study deals with the determination of the physicochemical parameters and iodine enrichment of rock salt mined in Keana Local Government of Nasarawa State. Five samples were collected from different pot spots and analysed for their physicochemical parameters as well as seeking cost effective ways of enriching the rock salt with iodine to help combat cases of goitre and brain retardation which are iodine deficiency diseases. The physicochemical parameters: pH, alkalinity, conductivity, total dissolved solids (TDS) and total suspended solids (TSS), were determined in the rock salt. The values ranged as follows: pH (6.0 – 8.2), conductivity (10.35 – 10.340S/cm), alkalinity (0.01 – 0.04mg/L), total dissolved solids (1570 – 1583mg/L ) and total suspended solids (0.03 – 0.19mg/L). The results of the physicochemical parameters where all below the permissible limit except for TDS which was higher than the permissible limit. The rock salt was also enriched with potassium iodate using the spray (wet) method and dry method. The result of the iodometric titration shows that rock salts were enriched with iodine. Using the spray method, iodine levels were within the range 75.15 – 80.14ppm, while salts enriched using dry method indicated that iodine levels were within the range 34.27 – 38.94ppm. The result shows that iodine enrichment using the spray method is more effective in attaining recommended level of iodine in rock salt at the point of production.