Extraction and purification of samples were carried out using a slightly modified method as described by Iqbal et al. (2010b). The whole chilli samples were ground to uniform consistency in a coffee mill. Samples of these and the already ground chillies (25 g) were extracted with 100ml of acetonitrile/water (86:14v/v) by shaking for 35 min at 50 rpm in 250-ml glass flasks fitted with a stopper. The solutions were filtered through Whatman No. 5 papers. To 9-ml portions of the filtrates, 70 ml acetic acid was added; the mixture was then transferred to MycoSep columns (product code 226) and passed through at a flow rate of 2 ml min 1. A 2-ml portion of each eluate was taken and evaporated to dryness at 40 1C in a centrifuge glass tube for pre-column derivatization. A 100-ml volume of TFA was added to the residues or AFs standards to derivatize residue samples. The sample was allowed to stand at room temperature for 20 min in the dark. A 0.4 ml mixture of acetonitrile/water (1:9v/v) was added to the tube before the injection to HPLC.