This study was conducted to determine the recent level of contamination with Fumonisin B1 (FB1) and Fumonisin B2 (FB2) in major medicinal plants and to assess consumer exposure in northern Turkey. FB1 and FB2 were investigated by using high performance liquid chromatography (HPLC) with fluorescence detection after derivatization with o-phthaldialdehyde (OPA). A total of 78 homemade medicinal plant samples from 14 species were analysed. The recovery in thyme was 67.2±5.2% for FB1 and 80.8±14.3% for FB2 spiked with 1 μg g–1 of each analyte. The minimum detectable amount for the OPA derivatives of FB1 and FB2 were 1 ng per injection and 2.5 ng per injection, respectively. The limit of quantitation (LOQ) S/N=10 was 0.078 and 0.313 μg g–1, and the limit of detection (LOD) S/N=3 was 0.023 and 0.093 μg g–1 for FB1 and FB2, respectively. FB1 was detected in thyme (0.125) and mint (0.125 and 0.256 μg g–1) samples; however. FB2 toxin was below the detection limit in all samples. These results indicate that toxins might be present in homemade medicinal plants; however, the risk of exposure to fumonisins by the consumption of those plants was lower than the estimated TDI limits (–1 bw)
