F. Determination of Method Precisio

F. Determination of Method PrecisionThe precision of an analytical procedure expresses the closeness of agreement between a series of measurements obtained from multiple sampling of the same homogeneous sample under the prescribed conditions. Precision may be considered at three levels.Injection repeatability: Injection precision is measured by multiple injections, a minimum of n=6 is typically recommended, of the reference standard orsample solution at the 100% level and indicates the performance of the HPLC instrument using the chromatographic conditions on one particular day and in one laboratory. The relative standard deviation, RSD (%), as specified here, will determine the lowest variation limit of the analytical results. Repeatability for impurities determination is often assessed by making repeat injections typically n=6 of an impurity mixture and a statisticalevaluation maybe performed using area response.