System for DMS peak resolution
An apparatus for identification of chemical species by measurement of mobility as a function of high electric field and for generating unique compound-dependent signatures based on ion mobility at a plurality of peak RF voltages for a given compensation. The resulting detection data is compared against a library of data in order to identify a detected chemical species.
1. A method for identification of an unknown item in a sample traveling through an excitation field, the excitation field having a varying influence upon the mobility behavior of the sample traveling the excitation field, the method comprising the steps of:
generating a varying excitation field;
subjecting a sample to the excitation field, the sample having field-dependent mobility behavior that reflects field conditions, and the excitation field having sufficient strength to fragment the sample;
subjecting the sample to a plurality of field conditions in the excitation field;
compensating the plurality of field conditions to pass the unknown item through the excitation field; and
identifying the unknown item as a member of a known species, the identification being based on known field-dependent mobility behavior of the known species in the plurality of compensated field conditions.
2. A method as in claim 1 wherein the fragmenting produces positive and negative ions.
3. A method as in claim 2 comprising identifying the positive and negative ions over a rage of compensation voltages.
4. A method as in claim 1 comprising varying the excitation field to produce ionized monomers.
5. A method as in claim 1 wherein the plurality of field conditions are varied over a range of dispersion voltages to produce multiple attributes of the field-dependent mobility behavior dependent on compensation voltage.
6. A method as in claim 5 wherein the multiple attributes are peaks, and each of the peaks identifies a particular ion.