Abstract:

In a Britton-Robinson（BR） buffer solution of pH=10.0, Pd(Ⅱ) and carbendazim(CBZ) can form a 1∶1 chelate complex. As a result, new spectra of resonance Rayleigh scattering(RRS), secondorder scattering(SOS), and frequency doubling scattering(FDS) appears and their intensities are enhanced greatly. The maximum wavelengths of RRS, SOS and FDS are located at 309 nm, 606 nm and 310 nm, and their intensities are proportional to the concentration of CBZ in certain ranges. The methods have a high sensitivity with the detection limit of 7.1×10-9 g/mL for RRS method, 7.4×10-9 g/mL for SOS method and 1.07×10-8 g/mL for FDS method, respectively. Based on the above results, a new light scattering method for the determination of trace amounts of CBZ has been developed. The RRS method with the highest sensitivity is taken for the determination of carbendazim in celery and wettable powder. The results are consistent with those of the GB method. In addition, the reaction mechanism and the reasons of the enhancement of resonance light scattering are discussed.

Key words: Carbendazim, palladium(II), resonance Rayleigh scattering, second-order scattering, frequence doubling scattering