Fig. 4.

Overview of the score evaluation function for the most discriminating features for three homogenous workflows (see Fig. 3) when comparing the 16-fold pLLOQ spiked samples with the blank (0.1-fold pLLOQ) obtained with the human urine data set. The bars at the bottom of the graph provide visual indication of the ranks at which features related to the spiked peptides were found for the respective workflow (blue, OpenMS; orange, SuperHirn; red, MZmine). Non-spike-related features are represented in this subplot as white squares. The OpenMS workflow found only one non-spiked-related feature up to rank 48, whereas the other two workflows showed a less consistent performance, leading to lower scores.