Multi-channel electroanalysis of As (III), Hg and Cu in the complex matrix of Bombyx batryticatus after pre-purification

The resources of animal medicinal materials have gradually attracted the attention of people around the world, however, the increase of heavy metals in animal medicine possesses a serious threat to human health. A multi-channel analysis technique with high accuracy and sensitivity become more urgent and necessary, particularly in such complex animal matrix which contains various interference components. Here, a multi-channel analysis strategy for the detection of As (Ⅲ), total Cu and Hg at trace level in Bombyx batryticatus was established by using square wave anodic stripping voltammetry (SWASV) on prepared Au nanoparticles (AuNPs) combined with four different purification procedures. Firstly, a nano-sized uniform spherical AuNPs material was electro-deposited onto a bare Au substrate, which leads to the enhancement of effective working area at 6.98% after modification. Secondly, the animal matrix was purified by electrochemical deposition (ED) and special removal materials for the methodology study in positive samples, which proved that above purification procedure can reduce interference and lower the current baseline of Bombyx batryticatus matrix successfully. Thirdly, the electrochemical property of As (Ⅲ), Cu and Hg was obtained successfully, and the validation result was demonstrated that the intensity of the significant anodic peaks of As, Cu and Hg at −0.045 V, 0.177 V and 0.322 V were proportional (R2 = 0.9996, 0.9929, 0.9987) to their concentrations in the purified sample solution in the range of 0.01–0.10 mg L−1, with a satisfactory recovery rate (97.50%–103.00%) and detection limits (0.0004 mg L−1, 0.0013 mg L−1 and 0.0035 mg L−1). Therefore, the proposed SWASV technique combined with purification procedure would have wide application prospect especially on the online monitoring of multiple heavy metals in other animal drugs.