The linear dynamic range of EC for plasma extraction (0-38 ng/mL) and for distillers grains co-products extraction (0-1600 ng/g) are shown in Figure (next page). Despite that the calibration curve for plasma assay was obtained from samples with EC spiked in plasma matrix and that for distillers grains assay was obtained from samples with EC spiked in 100% water, their LOD and LOQ were very close, i.e., 0.8 and 2.7 ng/mL respectively for plasma assay, and 0.7 and 2.6 ng/g respectively for distillers grains assay. The detection limit in this study is lower than most of the published results , but higher than the 0.4 ng/mL in wines and 0.3 ng/mL in wines after BSTFA derivations .