Chemistry-PTM-OMA_Modules_1-4

Analyzing Data – Qualitative Method SLV

• Method comparison achieved by estimating bias of candidate method • Bias estimated as dPOD, the difference between two POD values • dPOD C = POD C – POD R = bias between candidate and reference method results • Calculate 95% confidence intervals on dPOD values • If the confidence interval on dPOD does not contain zero, then the two POD values  are statistically different (bias is significant). • If no reference method, determine lowest level that achieves POD = 1.0. • For antibiotics in milk (FDA CVM program), use probit analysis to determine  concentration that yields 90% POD with 95% confidence.