Measuring method, a kit for measuring hemoglobin and hemoglobin derivatives

Together to quickly and reliably denatured hemoglobin in the sample solution, to achieve a measure of rapid and accurate hemoglobin and hemoglobin derivatives. Method for measuring hemoglobin and hemoglobin derivatives, reagent composition used therefor, measurement kit, an analysis device, and in the analysis system to a sample solution containing blood components, treated with a nonionic surfactant, an oxidizing agent and a metal salt by denaturing the hemoglobin in the sample solution, after measuring the hemoglobin, measuring the hemoglobin derivative content in the sample by immunoassay using an antibody which specifically binds to denatured site of the modified hemoglobin derivative.