Investigation into contamination of processed fruit products by carbendazim, methyl thiophanate and thiabendazole

A reversed phase high-performance liquid Chromatographic (HPLC) method was used for determining benomyl and its metabolites carbendazim, thiabendazole and methyl thiophanate in fruit products (nectars, purees, concentrates and jams). The residues were extracted with HCl/methanol and partitioned into dichloromethane on an Extrelut 20 cartridge column. The fungicides were then separated on a reversed phase HPLC column using an ion-pairing mobile phase and finally determined by UV and fluorescence detection. Eighty-three samples of commercial fruit products were analysed by this method. Positive samples were confirmed by normal phase chromatography using a Diol column. The determination limit was 0.010 mg kg−1 for carbendazim and methyl thiophanate, and 0.001 mg kg−1 for thiabendazole.