Differential mobility spectrometer: optimization of the analytical characteristics

Differential mobility spectrometer is a powerful tool used for detection, filtration and characterization of ions in gas-phase. DMS instrumentation analytical performance is a matter of importance for practical application. This paper is devoted to the improving of the planar DMS analytical characteristics. The goal is to optimize ion transmission and separation efficiency for the best possible DMS performance, balanced between sensitivity and selectivity. Analytical characteristics of the DMS instrument depend on a number of interrelated parameters. Present paper focuses on the sensor geometry and transport gas flow rate and its influence on the DMS performance. To find optimal sensor design parameters a systematic approach to the DMS performance is provided and evaluated both theoretically and experimentally. To facilitate DMS optimization special criterion quantitatively describing DMS analytical quality is proposed. DMS instrumental parameters maximizing analytical quality are determined. Theoretical analysis is validated by comparison with experimental data. Practical recommendations following from these finding are presented.