Analysis of Total Amino Acids in Rice Using a Validated Reversed-Phase High Performance Liquid Chromatographic Method with Diode Array Detection (RP-HPLC-DAD)

Adaptable to any routine laboratory, the study presents the validation results of a simple, accurate and reliable method developed for the analysis of total amino acids (TAAs) in rice using reversed-phase high-performance liquid chromatography-diode array detection (RP-HPLC-DAD). Exhibiting excellent selectivity with resolution (Rs) ≥ 2 for seventeen amino acids, the method was proven accurate against the analysis performed on the certified reference material (CRM): NIST 3233. Percentages of recoveries were in the range 86% - 100% with percentage relative standard deviation (% RSD) ≤ 6% for all amino acids. Limit of detection (LOD) and limit of quantification (LOQ) values were within 0.024-0.069 g/100 g and 0.025-0.078 g/100 g respectively. A wide working range with satisfactory linearity having regression coefficients ≥ 0.999 were reported for all the amino acids. Complying with international guideline requirements, this validated method can be successfully applied for the determination of seventeen TAAs including all essential amino acids in rice.