Determination Of Trace Cadmium In Environmental Samples With A Modified Electrode Method

In the paper，the trace cadmium in environmental samples was measured by twochemically modified electrode’s methods. one was modified with carboxylatednanoparticles-graphene on the surface of glasscarbon electrode, another withpre-electroplating bismuth film. The mechanism and results of determination were anlysedsimply.The carbonylsted nanographene modified electrode was prepared by modifiedcarbonylsted nanographene on glassy carbon electrode which obtained by treatingnanographene slices with acid. The bismuth film electrode was prepared inserting glassycarbon electrode in the Bi3+solution and metal Bi deposited on electrode’s surface for240s.The experiment’s conditions were optimized and the trace cadmium concentration wasdetermined under the experimental conditions.The experimental results showed that carbonated nanoparticles-graphene electrode canbe used to determine trace cadmuth in the environment samples. The peak current andCd²⁺concentration present a good linear between2.0×10-7～2.0×10-9molï¹’L^-1,detection limitwas2.2×10-10molï¹’L^-1.the experimental optimum conditions were that buffer solution was0.1mol·L^-1NaAc-HAc（pH=4.8）, Accumulation potential-1.1V，Accumulation time360s,scanvoltage-0.1～-0.4（vs s.c.e）.The linear range of bismuth film modifed glasscarbon electrodewas1.0×10-6～2.0×10-8molï¹’L^-1, detection limit was8.2×10-9molï¹’L^-1.The two modifiedglassy carbon electrode ‘s experimental conditions were same as each other.The experiment results showed that carbonylsted nanographene modified electrodepossesses a wider linear range and a lower detection limit. The method may be used todetermine trace cadmium in environmental samples.