共振瑞利散射法测定尿中痕量砷

Determination of urinary arsenic by resonance Rayleigh scattering method

建立了一种测定尿中痕量砷的共振瑞利散射（RRS）新方法。在pH=5.6的HAc-NaAc缓冲溶液中，I^-3与硫酸耐而蓝生成稳定的离子缔合物，体系共振瑞利散射增强。当加入微量As（Ⅲ）时，碘能定量氧化As（Ⅲ），导致共振瑞利散射减弱，在0.10-4.0μg／25mL浓度范围内，共振瑞利散射强度的改变值△TRRS与As（Ⅲ）浓度呈线性关系，方法检出限为1.65μg／L。用于尿中痕量砷的测定，回收率为93.5％—106.7％。

A resonance Rayleigh scattering method is proposed for the determination of urinary arsenic, I^-3 reacts with Nile blue sulphate to form an ion-association complex in the buffer of HAc-NaAc. The decrease of resonance Rayleigh scattering intensity is linear to the concentration of arsenic（m） in the range of 0.10—4.0μg/25 mL with the detection limit of 1.65μg/L. The method was applied to the determination of urinary arsenic with satisfactory results. The recoveries obtained were 93.5%-106.7%.