在H2SO4介质中,有机磷乐果和钼酸钠、酒石酸锑钾反应,生成淡黄色的有机磷锑钼三元杂多酸,纳米金在726 nm处产生一个较强的共振散射峰。抗坏血酸可将该有机磷锑钼杂多酸还原为有机磷锑钼杂多蓝,导致726 nm处共振散射峰的强度降低。乐果质量浓度在0.014~1.66μg/mL范围内与共振散射光强度降低值ΔI呈良好的线性关系,其回归方程为ΔI=155.4ρ+1.4,相关系数为0.9970,方法的检出限为3.9 ng/mL,该法可用于废水中乐果的测定。
Organic phosphorus dimethoate reacted with molybdate and antimony tartrate potassium to from organophosphoantimomolybdate heteropoly acid in light yellow,and the nanogold exhibited a strong resonance scattering peak at 726 nm in 0.012 mol/L H2SO4.When ascorbic acid was added,the heteropoly acid was reduced to organophosphoantimomolybdate blue that resulted in the resonance scattering intensity quenching at 726 nm.The decreased intensity ΔI was linear to the concentration of dimethoate in the range of 0.014~1.66 μg/mL,with regression equation of ΔI=155.4ρ+1.4,correlation coefficient of 0.9970,and detection limit of 3.9 ng/mL.This resonance scattering method was applied to the analysis of dimethoate in waste water samples,with simplicity,rapidity and accuracy.