Document - FAVV

Evaluation of immunoassay kits for determination of ochratoxin A in cerealsprobability of error, usually of 5%. In the particular case of problems related to the maximum permitted level, thecut-off value is related to the sensitivity, as it corresponds to the concentration level at which the sensitivity rate is95%, when the β -type error probability has been set at 5%.3.2.4.1 Calibration requirementsEuroproxima doesn‟t include a solution to verify the performance of the kit (Table 30).Table 30: StandardsEuroproximaR-BiopharmNegative Control No NoCut-off control No YesMulti Cut-off control No No3.2.4.2 Determination of unreliability regionTable 31: Unreliability regionMatrixUnreliability regionEuroproxima Coffee (roasted, ground and green) 3.5-4 ng/gR-Biopharm Green coffee, Cereals NSThe unreliability region for the Europroxima kit lies below the legal limit imposed for coffee (5 ng/g).3.2.4.3 Precision, sensitivity and specificityTable 32: False positives/negatives & true positives/negatives ratesPerformance parameters Formulas Europroxima R-BiopharmNumber samples / 126 NSFalse positive rate FP/(FP + TN) 1.6% NSFalse negative rate FN/(TP + FN) 0% NSSensitivity rate TP/(TP + FN) 100% NSSpecificity rate TN/(TP + FP) 97% NSPositive predictive value TP/(TP +FP) 98% NSNegative predictive value TN/(TN + FN) 100% NS3-32 Administrative evaluation | CODA-CERVA