Empower and Named Group

[theforce007]

I am using Waters Empower 3 FR 2. I know how to create a Named Group by selecting the relevant peaks. However, I do not understand the different selections for "Source of Calibration X value". Anyone happen to understand the difference between User Enter and Sum Peaks? Would appreciate if anyone could help.

[shaun78]

from the empower help:

User Entered, Curve or Sum Peaks for Quantitation (default)

During calibration, Empower reads the amount or concentration for the calibration curve point for the Timed Group from the sample (as entered during sample loading) or from the Default Amounts tab.

During quantitation (when there is a calibration curve for the group), Empower uses the group's Y value and the calibration curve to calculate the X value.

During quantitation (when there is no calibration curve for the group), Empower sums the X values of the peaks in the group to calculate the X value for the group.

Tip: Empower adds a processing code of Q20 to the peak to indicate that a calibration curve was not used to quantitate the

Sum Peaks, Curve or Sum Peaks for Quantitation

During calibration, Empower sums the X values of the peaks in the group to produce a group X value that is used to create a calibration point for the calibration curve.

During quantitation (when there is a calibration curve for the group), Empower uses the group's Y value and calibration curve to calculate the X value.

During quantitation (when there is no calibration curve for the group), Empower sums the X values of the peaks in the group to calculate the X value for the group.

Tip: Empower adds a processing code of Q20 to the peak to indicate that a calibration curve was not used to quantitate the peak.

Restriction: You cannot include a component that has a curve reference and Exclude Known Peaks in a timed group.

Not Calibrated, Sum Peaks for Quantitation

During calibration, Empower does not calibrate the group and the group peak has no X value.

During quantitation, Empower sums the X values of all the peaks in the group to calculate the group's X value. using their own or another component's calibration curve ( curve reference or default peak).

Restriction: If another component lists the group as a curve reference or default peak, you cannot set the X value of the group to Not Calibrated, Sum Peaks for Quantitation. A component designated as a curve reference or default peak must have a calibration curve.