din32645. chemCal 0.1-35.900

Usage

data(din32645)

+ +

Description

+ +

Sample dataset to test the package.

+ +

Format

+ +

A dataframe containing 10 rows of x and y values.

+ +

References

+ +

DIN 32645 (equivalent to ISO 11843), Beuth Verlag, Berlin, 1994

+ +

Dintest. Plugin for MS Excel for evaluations of calibration data. Written + by Georg Schmitt, University of Heidelberg. + http://www.rzuser.uni-heidelberg.de/~df6/download/dintest.htm

+ +

Currie, L. A. (1997) Nomenclature in evaluation of analytical methods including + detection and quantification capabilities (IUPAC Recommendations 1995). + Analytica Chimica Acta 391, 105 - 126.

+ +

Examples

data(din32645)
+m <- lm(y ~ x, data = din32645)
+calplot(m)
+
+
+
+## Prediction of x with confidence interval
+(prediction <- inverse.predict(m, 3500, alpha = 0.01))
+
+$Prediction
+[1] 0.1054792
+
+$`Standard Error`
+[1] 0.02215619
+
+$Confidence
+[1] 0.07434261
+
+$`Confidence Limits`
+[1] 0.03113656 0.17982178
+
+
+
+# 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$Confidence,5)
+
+[1] 0.07434
+
+
+## Critical value:
+(crit <- lod(m, alpha = 0.01, beta = 0.5))
+
+$x
+[1] 0.0698127
+
+$y
+       1 
+3155.393 
+
+
+
+# According to DIN 32645, we should get 0.07 for the critical value
+# (decision limit, "Nachweisgrenze")
+round(crit$x, 2)
+
+[1] 0.07
+
+# and according to Dintest test data, we should get 0.0698 from
+round(crit$x, 4)
+
+[1] 0.0698
+
+
+## Limit of detection (smallest detectable value given alpha and beta)
+# In German, the smallest detectable value is the "Erfassungsgrenze", and we
+# should get 0.14 according to DIN, which we achieve by using the method 
+# described in it:
+lod.din <- lod(m, alpha = 0.01, beta = 0.01, method = "din")
+round(lod.din$x, 2)
+
+[1] 0.14
+
+
+## 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))
+
+$x
+[1] 0.2119575
+
+$y
+       1 
+4528.787 
+
+
+round(loq$x,4)
+
+[1] 0.212
+
+
+# A similar value is obtained using the approximation 
+# LQ = 3.04 * LC (Currie 1999, p. 120)
+3.04 * lod(m,alpha = 0.01, beta = 0.5)$x
+
+[1] 0.2122306
+

+ + + +

Calibration data from DIN 32645

Usage

Description

Format

References

Examples