Intermediate precision includes the influence of additionalrandom effects such as operator, instrument, and days inthe laboratory was calculated through inter-day precisionmethod by injecting of three replicates of differentconcentrations of HMPHA (4.5, 6, 8, 10, 12.5 and 15 μg/mL) on three consecutive days in a week (n=9). Peak areawas measured and % RSD was calculated (13,14).