Résumé
Objective:To establish a volt-ampere polarography method for the determination of thimerosal in chondroitin sulfate eye drops, and study the adsorption of thimerosal in different packing materials. Methods:The hanging mercury drop electrode ( HM-DE) in multi-functional electrode was used and the sample solution was added to potassium chloride-hydrochloric acid buffer solution. Nitrogen deoxygenation time was 200 s, the enrichment time was 60 s, and the equilibrium time was 5 s. The potentiometric scan was performed using a two standard addition method. Results:Thimerosal had a good linear relationship within the range of 0. 01-1. 0 mg· ml-1(r=0. 9990). The detection limit was 1. 78 μg·ml-1 and the average recovery was 99. 1% (RSD=2. 7%, n=9). Conclu-sion:The method is simple and accurate, and suitable for the determination of thimerosal in chondroitin sulfate eye drops. Low-density polyethylene and polypropylene both show obvious adsorption of thimerosal,so chondroitin sulfate eye drops should not be packed in the above packing materials.