Dynamic range improvement for mass spectrometry
View Patent ↗Embodiments of the present disclosure provide methods of controlling an ion detector to minimize false peaks when utilizing extended dynamic range techniques. In one exemplary example, methods of controlling an ion detector are provided, comprising the steps of: determining an electronic baseline signal of the ion detector; receiving one or more ion input signals at the ion detector; comparing the ion input signal to the electronic baseline signal; and multiplying the ion input signal by a selected compensation factor when the ion input signal exceeds the electronic baseline signal.
1. A method of minimizing false peaks in a mass spectrometer having an ion detector that uses extended dynamic range techniques in forming a detector output signal, the method comprising the steps of:
initially measuring a plurality of baseline electronic signals characteristic of the mass spectrometer;
setting a Baseline threshold value equal to one of:
Baseline threshold value=baseline average +(baseline max −baseline min ) (i)
where baseline average is an average of the plurality of baseline electronic signals, baseline max is the maximum baseline electronic signal measured and baseline min is the minimum baseline electronic signal measured, and
Baseline threshold value=baseline average +SD (ii)
where baseline average is an average of the plurality of baseline electronic signals and SD is a standard deviation of the average of the plurality of baseline electronic signals;
receiving one or more ion input signals at the ion detector;
comparing each ion input signal to the Baseline threshold value; and
multiplying each ion input signal by a selected compensation factor when the ion input signal exceeds the Baseline threshold value while excluding those ion input signals which are below the Baseline threshold value from the multiplication, such that the output signal includes ion input signals that have been multiplied by the compensation factor and ion input signals that have not been multiplied by the compensation factor.
2. The method of claim 1 wherein the selected compensation factor is determined based on the intensity of at least one of the received ion signals.
3. The method of claim 1 further comprising: adjusting the selected compensation factor by adjusting a control voltage applied to the ion detector in response to the intensity of the one or more ion input signals.
4. The method of claim 1 further comprising establishing or extracting a multiplier voltage and determining the selected compensation factor from a look-up table or calibration curve having compensation factor verses multiplier voltage values.
5. A non-transitory computer readable medium including software for controlling an ion detector of a mass spectrometer, the computer readable memory comprising logic configured for implementing the steps of:
initially measuring a plurality of baseline electronic signals characteristic of the mass spectrometer;
setting a Baseline threshold value equal to one of:
Baseline threshold value=baseline average +(baseline max −baseline min ) (i)
where baseline average is an average of the plurality of baseline electronic signals, baseline max is the maximum baseline electronic signal measured and baseline min is the minimum baseline electronic signal measured, and
Baseline threshold value=baseline average +SD (ii)
where baseline average is an average of the plurality of baseline electronic signals and SD is a standard deviation of the average of the plurality of baseline electronic signals;
receiving one or more ion signals at the ion detector;
comparing each ion input signal to the Baseline threshold value; and
multiplying each ion input signal by a selected compensation factor when the ion input signal exceeds the Baseline threshold value while excluding those ion input signals which are below the Baseline threshold value from the multiplication such that an output signal of the detector includes ion input signals that have been multiplied by the compensation factor and ion input signals that have not been multiplied by the compensation factor.
6. The non-transitory computer readable medium of claim 5 further comprising logic configured for implementing the step of: establishing or extracting a multiplier voltage and determining the selected compensation factor from a look-up table or calibration curve having compensation factor verses multiplier voltage values.
7. The non-transitory computer readable medium of claim 5 wherein the selected compensation factor is determined based on the intensity of at least one of the received ion signals.
8. The non-transitory computer readable medium of claim 5 wherein the steps implemented by the logic of the computer readable memory further comprise adjusting the selected compensation factor by adjusting a control voltage applied to the ion detector in response to the intensity of the one or more ion input signals.
9. The method of claim 5 wherein the steps implemented by the logic of the computer readable memory further comprise establishing or extracting a multiplier voltage and determining the selected compensation factor from a look-up table or calibration curve having compensation factor verses multiplier voltage values.