MOOC: Validation of liquid chromatography mass spectrometry (LC-MS) methods (analytical chemistry) course

Bonus self test 9.5

1.

Estimate CCα and CCβ for LC-MS/MS measurements of thiazophos from tomatoes using the method given in ISO 11843-2. Use ValChrom to estimate CCα and CCβ. For those who want to understand the calculation processes behind CCα and CCβ|full calculation logic can be found at [ref 18].

c(triasophos|mg/kg)

Parallel 1

Parallel 2

Parallel 3

Parallel 4

0

495

2834

1687

306

8.04E-06

419

981

1777

2141

9.78E-05

3177

6228

2803

4933

5.21E-04

11740

15274

13275

16857

1.21E-03

31638

37982

25181

32632

2.83E-03

60897

60702

60501

63998

For use with ValChrom: cca_and_ccb_4_parallels.xls  Use α=β=5% and K=4 during upload.

Write results with 3 significant digits.

Estimation for CCα: (Enter your answer here)

Estimation for CCβ: (Enter your answer here)

2.

Estimate LoD from the same given data using ICH method based on calibration graph and residual deviation of residuals.

Write results with 3 significant digits: (Enter your answer here)

3.

Which guideline is more conservative at its estimate of detection capabilities: ICH or ISO?

4.

Which guideline makes more assumptions: ICH or ISO?