Performance Parameters, Calculations and Tests

The quantification of ellagic acid in the crude extract of Phyllanthus amarus Schum. & Thonn. (Euphorbiaceae)

“…The residuals were randomly scattered and showed a condition of homoscedasticity. The highest residual corresponded to 1.4% of the signal of the 100% concentration, which is within the limit of 5% for LC‐UV (Ermer, 2005a). The point (0,0) fell within the calibration curve since zero was included in the confidence interval, meaning that a single‐point calibration is allowed.…”

Matrix-specific method validation for quantitative analysis of vitamin C in diverse foods

“…Limits of detection and quantitation. The limit of detection (LOD) and limit of quantitation (LOQ) were estimated statistically from a diluted calibration curve (0.01-1.60 mg/mL of AA), as 3*SE/S and 10*SE/S respectively (Ermer et al, 2005;Hibbert, 2007), where SE is the standard error of the regression and S the slope of the curve. In addition, the LOD and LOQ were estimated empirically, by progressively measuring AA in serially diluted AA standard solutions (0.01-0.2 mg/mL).…”

Determination of parthenin in Parthenium hysterophorus L. by means of HPLC-UV: Method development and validation

“…Since the within-days RSD (1.45%) and the between-days RSD (1.36%) are in the same order of magnitude, the method can be considered to be precise. In addition, the between-days RSD was smaller than the limit (2.11%), calculated by the Horwitz formula: RSD max = 2/3RSD Horwitz in which RSD Horwitz = 2 (1À0.5logC) (Ermer, 2005). The overall average amount of parthenin found in the plant material was 4.71% with an RSD of 1.39%.…”