Self test 10.1

Ion source configuration can influence spray and ionization efficiency in the ion source 

Nebulizer gas pressure/flow rate can influence analyte ionization efficiency in the ion source. 

Drying gas temperature does not influence my method performance. 

Changes in the ion source cleanliness can affect method performance during the analytical run.

Evaluation of the changes in the ion source configuration is not needed if the source is fixed.

Injection solvent composition (the solvent used in the last step of sample preparation) do not influence my method’s performance, since I use the same solvent composition each and every time.

Extraction time, amount of solvent used during the extraction and also the composition of the solvents in the sample preparation procedure influences recovery and LoQ/LoD.

Different matrices do not influence my method’s performance if I have evaluated matrix effects for my method. 

Changes in the salts and ion pair reagents concentrations do not have an effect to the method performance.

Column batch and age can influence the retention time, resolution and possibly therefore also ionization. 

Changes in eluent flow rate should be excluded in robustness tests since my LC-MS method is saved with fixed flow rate and therefore I do not need to evaluate the influence of this parameter. 

Changes in pH have a high impact on method performance in if analyte’s pK_a value is very close to the eluent pH.

Pyrrolidine

Piperidine

2-methylpyridine

2-nitrophenol

2,5-dinitrophenol

3-nitroaniline