Research Article

Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

Figure 3

Determined split peak in serum with the transition m/z during method development. The split peak was measured on several HPLC columns after SPE purification by Oasis MCX. In grey, the ion count of a low enalaprilat concentration in serum is shown that clearly identifies the split peak. As reference, the enalaprilat standard solved in mobile phase is presented by the black line without any split peak (base line is nudged to prevent overlap).