Abstract

This study compares the high performance liquid chromatography (HPLC) and ultrahigh performance liquid chromatography (UPLC) methods for the determination of melatonin in rice extracts. The methods were validated in terms of linearity, precision, limits of detection (LOD) and quantification (LOQ). Repeatability and intermediate precisions expressed as coefficient of variation (CV) were less than 2.5% for HPLC and 1.5% for UPLC. Linear regression models fit perfectly the standard curves with R2 > 0.99 for both methods. The LODs were 1.15 μg L-1 and 0.73 μg L-1 while LOQs were 3.84 and 2.19 μg L-1, for HPLC and UPLC respectively. High efficiency UPLC gradient is feasible and beneficial to substitute the conventional analysis of melatonin in rice grain by HPLC as permitted the analysis run time to be reduced to one six thus consumes less eluents.