Both intraand inter-day assay precisions [repeatability relative standard deviation (RSDr) and reproducibility relative standard deviation (RSDR)] were determined by analyzing three spiked concentrations of 0.1, 1.0, and 5.0 mg/g, five sets each with blank. However, intraday assay precision was determined at three occasions at least 6 h apart,whereas inter-day precision was determined at three successive days