Bonus self test 9.5 – Validation of liquid chromatography mass spectrometry (LC-MS) methods

1. Estimate CC_α and CC_β for LC-MS/MS measurements of triazophos from tomatoes using the method given in ISO 11843-2. Use ValChrom to estimate CC_α and CC_β. For those who want to understand the calculation processes behind CC_α and CC_β,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 CC_α: (Enter your answer here)

Estimation for CC_β: (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?

ICH

ISO

4. Which guideline makes more assumptions: ICH or ISO?

ICH

ISO