HP Data Explorer 4 Charge state determination troubleshooting

Chapter 3 Peak Detection and Labeling

Effect of Minimum

Intensity

The Minimum Intensity setting on the Advanced Settings tab can also determine how charge states are determined for a peak, because it determines if the software can find a match for a peak. Figure 3-12illustrates two peaks correctly labeled with charge state 1.

		Figure 3-12 Minimum Intensity Set Correctly
	If you increase the Minimum Intensity setting to 85 in the
3	example shown in Figure 3-12,the software cannot determine
	a charge state for the first peak (Figure 3-13). This is because:
		• The increased threshold suppresses the detection of the
		236.6 m/z peak.
		• When the software evaluates the peak at 235.6 m/z, it
		does not find a peak at the appropriate peak spacing for
		charge state 1, and therefore determines that the peak
		has no calculated charge.

Charge state determination troubleshooting

Figure 3-13 Minimum Intensity Set Incorrectly

See Table 9-12, “Charge State and Isotope Determination Troubleshooting— Mariner Only,” on page 9-18.

3-36 Applied Biosystems