Mass analysis system with low pressure differential mobility spectrometer

An ion analyzer comprising:

• a ion source,
• a flow of ions from the ion source,
• a reaction region for introducing at least one modifier to the flow of ions,
• a first DMS, operating substantially at atmospheric pressure, for receiving the flow of ions from the reaction region, the first DMS performing a first mobility based filter operation on the flow of ions,
• a declustering region, operating at less than atmospheric pressure, for receiving the flow of ions from the first DMS, and
• a second DMS, operating at less than atmospheric pressure, for receiving the flow of ions from the declustering region and performing a second mobility based filter operation on the flow of ions.

An ion analysis system comprising:

• an ion source,
• a flow of ions from the ion source,
• a first means for modifying a first portion of ions from the flow of ions to alter the □ function associated with the first portion of ions,
• a first DMS configured to receive the first portion of ions, conduct a differential mobility separation, and output a second portion of ions,
• a second means for modifying the second portion of ions to alter the □ function associated with the second portion of ions, and
• a second DMS configured to receive the second portion of ions, conduct a differential mobility separation, and output a third portion of ions.