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. 2011 Jan 28;83(4):1469–1474. doi: 10.1021/ac102265w

Figure 1.

Figure 1

A HCD cell with an axial field decreases the fraction of HCD spectra with missing reporter ions and improves analytical precision. Analysis of a standard protein mixture on an LTQ Orbitrap equipped with the original HCD cell as compared to a HCD cell with an axial field. Panel A indicates the percentage of HCD spectra where one or more reporter ions failed to be detected. The geometric standard deviation of “duplicate” channels is depicted in panel B (for the ratio 115:114) and panel C (for the ratio 117:116). Panel D shows the fraction of the precursor ion currents that can be detected as reporter ion currents, as a measure of fragment ion generation and transmission. In each panel (A−D) individual measurements are shown on the left side, whereas arithmetic averages with one-sided error bars denoting 1 SD are shown on the right side. p-values calculated as a 2-sided paired t test for the comparison of the original HCD cell vs the HCD cell with an axial field.