Ion chromatographic and voltammetric determination of heavy and transitionmetals in honey

Heavy metals in honey are of interest not only for quality control, but can be used also as an environmental indicator. In the present work, in order to minimize sample pre-treatment. the interference by organic constituents of the matrix is overcome by using oxidative UV photolysis. The matrix degr ades in less than 1 h, while most common metallic impurities, like iron, co pper. nickel. zinc, lead. cadmium and cobalt, remain unaffected by UV radia tion, with the exception of manganese. After UV photolysis. the resulting s olution is directly analyzed by ion chromatography and differential pulse a nodic or cathodic stripping voltammetry. In absence of official standards, the results obtained by these techniques on spiked matrix-matched blank sol utions and original and spiked real samples are compared with those of the well established electrothermal atomic absorption spectrometry and they are found in good agreement. The proposed techniques show satisfactory sensiti vity, detection limits and standard deviation for heavy and transition meta ls determination in honey. In addition. both ion chromatography and pulsed voltammetries permit multielement analyses which can be fully automated. (C ) 2001 Elsevier Science Ltd. All rights reserved.