3.1.2.3. Repeatablility. In order to express the precision under the same operating conditions over a short interval of time, repeatability of organic acids peak area was determined (Incledon and Lam, 2004) between 0.5% and 3.8% RSD. The results indicate that the present method can be applied to organic acids in brewed coffee.
Intermediate precision expresses within-laboratory variation and is generally performed on different days using different analysts, equipment and sample preparations (Incledon and Lam, 2004). Calibration was repeated at the end of the study, and repeatability (again, 5 concentrations/3 replicates each) of organic acids peak area was between 0.2% and 1.6% RSD.