A novel spectral method for determination of trace malathion using EryB as light scattering probe by resonance...

A convenient and sensitive spectrophotometric methods was proposed for determination of Malathion (Mala) using Erythrosin B (EryB) as a probe through the Resonance Rayleigh scattering (RRS) technique. The interaction between EryB, Pd²⁺and malathion in the system was investigated by fluorescence, RRS and UV-Vis spectroscopy. Under the optimum conditions, the RRS intensity of EryB, Pd²⁺ and malathion was weak when exist in alone or any two kinds, however, the RRS intensity of the EryB-Pd²⁺-Mala system had an obvious enhancement due to Pd²⁺ could interact with the hydrolysis products of Mala and EryB each other form a new complexes. At the same time, the fluorescence intensity of EryB was decreased significantly in the presence of Pd²⁺, and the fluorescence intensity of EryB-Pd²⁺ system further decreased when Mala added, interestingly. So it was further proved that there was a forming complex in EryB-Pd²⁺-Mala system. Under the optimal conditions, the RRS enhanced intensity of the system was linearly proportional to the Mala's concentration in the range of 0.012-0.8 μg/mL, and the LOD was 1.7 ng/mL, with the correlation coefficient was R² = 0.9960. So, a new method for determination of Mala was established and this method has been demonstrated in real sample with satisfactory results.