Improvements in ion-trap chemical-ionization performance

Ion‐trap chemical‐ionization performance has been imporved by application of a modified scan function for the rejection of the undesired electron‐ionization‐like (EI‐like) ions formed at the beginning of the reaction ionization period. The net effect of this software modification to the automatic reaction control is to produce chemical ionization (CI) spectra that are no longer adulterated with conventration‐dependent EI‐like ions. Under such improved conditions, CI spectra from an ion trap can now be dirctly compared with CI spectra produced on conventional quardrupole and magnet‐scanning instruments.