在pH 6.6的磷酸二氢钾-磷酸氢二钠缓冲溶液中,达旦黄(TY)与一定浓度的吐温-80发生荧光增强反应,当在该体系中加入辛硫磷农药后,在激发波长412 nm,发射波长460 nm处荧光强度明显降低,且降低程度与辛硫磷的加入量呈线性关系,方法的线性范围在0.72 mg·L-1以内,检出限(3S/N)为0.031 mg·L-1.据此建立了测定辛硫磷残留量的方法,该方法用于小米和土壤中辛硫磷残留测定,两者的平均回收率依次为93.5%和97.7%,测定值的相对标准偏差(n=5)分别为1.7%和2.6%.

In a phosphate buffer of pH 6.6,the fluorescence intensity of titan yellow (TY) was enhanced by its reaction with definite amount of Tween-80.But when microamounts of the insecticide phoxim was added to this reaction system,significant decrease in fluorescence intensity was observed as measured at the wavelengths of 412 nm (λex) and 460 nm (λem).Linear relationship between the magnitude of decrease in fluorescence intensity and the mass concentration of phoxim was obtained in the range within 0.72 mg·L-1.Detection limit (3S/N) found for this reaction system was 0.031 mg·L-1.Based on these facts,a rapid method for determination of residual amounts of phoxim by fluorospectrophometry was proposed,and applied to the analysis of samples of millet and soil.Values of average recovery found were 93.5% and 97.7%,and values of RSD′s (n=5) were 1.7% and 2.6% respectively.