Finding the Number of Points Across a Peak in Sciex OS Software

For research use only. Not for use in diagnostic procedures.

Answer

During method development one important parameter is the number of points across a peak. 10 to 12 data points are a minimum value to achieve accurate and reproducible peaks.

Options in Sciex OS software:
A: Explorer

• Open your data, extract a mass or MRM of interest, and select the peak.
• Select Window – Graph Selection Window in the menu (or press Ctrl + W)
• Selected Points will indicate the first and last data point of the selection. The amount of datapoints in this example would be 116-92+1=25
• If you click the last button in the header of the window, the data points will additionally be displayed

• In your results table, activate the column Points Across Baseline (More – Table display settings)
• You can also use the column Points Across Half Height. This displays the amount of data points across the upper half of the peak and is less depending o the alignment of the baseline. You should reach 5 to 6 points for quantitative workflows