Dynamic Ramps UI

Dynamic ramping allows you to change the voltage of the analyzer components listed below for selected m/z. For EI of PFTBA, ion masses exist at m/z 50, 69, 131, 219, 414, and 502. The end points of 2.6 AMU and 1049 AMU only represent the ends of the mass range and are not in the standard EI calibration compound.

The effect is to change the ion abundance surrounding a specified ion. If the results of a target tune indicate that you want to change the abundance of a particular ion, change the specified voltage and review your results.

Dynamic Ramping analyzer components

  • Width Offset - This affects the width of the mass peaks by adjusting the ratio of dc voltage to RF voltage on the mass filter. A higher value gives narrower peaks at all masses.
  • Repeller - This voltage repels ions from the ion source. If the voltage is set too low, too few ions will leave the source, resulting in poor sensitivity and poor high mass response. If it is set too high, too many ions at too high a velocity will leave the source. This results in precursors (poor mass filtering) and poor low mass resolution.
  • Ion Focus - Ion focus affects ion abundance.
  • Entrance Lens - This Voltage (V) value is actually the voltage gain (mV/amu) per unit mass that combined with the Ent Lens Offset voltage determines the voltage that is applied to the entrance lens.
  • Ent Lens Offset - Increase this voltage to increase the abundance of ions at low masses without substantially decreasing the abundance of ions at high masses.