From 40979ea0a74bbbfade1ce299415605f64215c0a4 Mon Sep 17 00:00:00 2001
From: Johannes Ranke data(din32645)
+ data(din32645)
Format
@@ -140,35 +140,42 @@
Analytica Chimica Acta 391, 105 - 126.
-- cgit v1.2.1++3.04 * lod(m, alpha = 0.01, beta = 0.5)$x +## Prediction of x with confidence interval -prediction <- inverse.predict(m, 3500, alpha = 0.01) +prediction <- inverse.predict(m, 3500, alpha = 0.01) # This should give 0.07434 according to test data from Dintest, which # was collected from Procontrol 3.1 (isomehr GmbH) in this case -round(prediction$Confidence, 5)#> [1] 0.07434#> [1] 0.07434## Critical value: -crit <- lod(m, alpha = 0.01, beta = 0.5) +crit <- lod(m, alpha = 0.01, beta = 0.5) # According to DIN 32645, we should get 0.07 for the critical value # (decision limit, "Nachweisgrenze") -round(crit$x, 2)#> [1] 0.07#> [1] 0.0698#> [1] 0.07#> [1] 0.0698## Limit of detection (smallest detectable value given alpha and beta) # In German, the smallest detectable value is the "Erfassungsgrenze", and we # should get 0.14 according to DIN, which we achieve by using the method # described in it: -lod.din <- lod(m, alpha = 0.01, beta = 0.01, method = "din") -round(lod.din$x, 2)#> [1] 0.14#> [1] 0.14## Limit of quantification # This accords to the test data coming with the test data from Dintest again, # except for the last digits of the value cited for Procontrol 3.1 (0.2121) -loq <- loq(m, alpha = 0.01) -round(loq$x, 4)#> [1] 0.212#> [1] 0.212# A similar value is obtained using the approximation # LQ = 3.04 * LC (Currie 1999, p. 120) -3.04 * lod(m, alpha = 0.01, beta = 0.5)$x#> [1] 0.2122306#> [1] 0.2122306