Document - FAVV

Evaluation of immunoassay kits for determination of ochratoxin A in cereals10,90,80,70,6B/B 00,50,40,30,20,100 4 8 12 16 20 24 28 32 36 40 44ng/gOTA OTB Otα CIT ZEA AFLA B1 COU 4-H-COU PHFigure 14: Standard curve of OTA, OTB, OTα, Citrinin, Zearalenone, AFLA B1, Coumarin, 4-HydroxyCoumarin and L-phenylalanine (n=2)4.5.2.2 MatrixIn Table 65 it can be seen that the IC 50 is strongly dependent on the matrix.Table 65: Cross-reactivity in matrixOTAOTBWheat Barley Oats Wheat Barley OatsSlope -1.010 -1.205 -0.824 -0.953 -1.096 -0.909Intercept 1.634 2.248 1.173 0.306 0.699 0.281R 2 0.910 0.888 0.931 0.967 0.960 0.943SE Intercept 0.158 0.212 0.111 0.087 0.111 0.111SE Slope 0.159 0.214 0.112 0.088 0.112 0.112IC50 (ng/g) 41.473 73.298 26.509 2.095 4.344 2.0364.5.3 Matrix effectThe results of this exercise are summarized in Table 66 and Table 67. The extraction protocol of the Ochratoxin-A-ELISA asks for a rather complex extraction procedure (Table 43). First 5 ml of 0.5 ml H 3PO 4 has to be added to 2.5grams of sample and shaked, subsequently 10 ml of dichloromethane is added and shaked again for 10 minutes.4-60 Experimental evaluation | CODA-CERVA