A digital filter for improved resolution in ion-mobility spectrometry

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7110092

Rico, G

Ion mobility spectrometry (IMS), formerly known as plasma chromatography, is an analytical technique for detecting organic compounds in gas phase at atmospheric pressure. This method of detection drew considerable attention from analytical chemists during the last decade or so, due to its very high detection sensitivity with gas concentrations at trace levels. The technique, however, has recently drifted away from being considered very powerful to standing as an interesting analytical method that has a high value from the sensitivity standpoint but is rather poor in resolution of information. Typical methods of filtering and conditions that affect resolution in IMS are described and evaluated. This work presents the design of an analog/digital system for detecting, conditioning, and filtering the signal from an IMS tube to obtain readable and reliable information for the analyst. The problem of signal amplification and filtering is thoroughly analyzed from analog signal conditioning, to measurement and estimation of noise and signal, to the design and implementation of the digital filter. There is a trade-off between resolution and amplitude of the detected signal, which in turn, is severely distorted by noise. The design presented here takes into account the random defocusing of the detected signal that directly affects resolution. Also taken into account is the fact that the detected signal is convolved with the impulse-response function of the signal amplifier that results in distortion of the acquired signal.

• Research Organization: New Mexico State Univ., Carlsbad, NM (United States)
• OSTI ID: 7110092
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CHROMATOGRAPHY
ELECTRONIC CIRCUITS
CHARGED PARTICLE DETECTION
DESIGN
EXPERIMENTAL DATA
ION MOBILITY
RESOLUTION
SIGNAL CONDITIONING
DATA
DETECTION
INFORMATION
MOBILITY
NUMERICAL DATA
PARTICLE MOBILITY
RADIATION DETECTION
SEPARATION PROCESSES
400102* - Chemical & Spectral Procedures