Chemical standards in ion mobility spectrometry

Journal Article · Sun Aug 01 04:00:00 EDT 2010 · Analyst, 135(6):1433-1442

DOI:https://doi.org/10.1039/B915202D· OSTI ID:1021835

Fernandez-Maestre, Robert; Harden, Charles S; Ewing, Robert G; Crawford, Christina L

In ion mobility spectrometry (IMS), reduced mobility values (K0) are used as a qualitative measure of gas phase ions, and are reported in the literature as absolute values. Unfortunately, these values do not always match with those collected in the field. One reason for this discrepancy is that the buffer gas may be contaminated with moisture or other volatile compounds. In this study, the effect of moisture and organic contaminants in the buffer gas on the mobility of IMS standards and analytes was investigated for the first time using IMS directly coupled to mass spectrometry. 2,4-Dimethylpyridine, 2,6-di- tertbutylpyridine (DTBP), and tetrabutylammonium, tetrapropylammonium, tetraethylammonium, and tetramethylammonium chlorides were used as chemical standards. In general, the mobility of IMS standard product ions was not affected by small amounts of contamination while the mobilities of many analytes were affected. In the presence of contaminants in the buffer gas, the mobility of analyte ions is often decreased by forming ion–molecule clusters with the contaminant. To ensure the measurement of accurate reduced mobility values, two IMS standards are required: an instrument and a mobility standard. An instrument standard is not affected by contaminants in the buffer as, and provides an accurate measurement of the instrumental parameters, such as voltage, drift length, pressure, and temperature. The mobility standard behaves like an analyte ion in that the compound’s mobility is affected by low levels of contamination in the buffer gas. Prudent use of both of these standards can lead to improved measurement of accurate reduced mobility values.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1021835
• Report Number(s): PNNL-SA-74103
• Journal Information: Analyst, 135(6):1433-1442, Journal Name: Analyst, 135(6):1433-1442 Journal Issue: 6 Vol. 135; ISSN ANALAO; ISSN 0003-2654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BUFFERS
CHLORIDES
CONTAMINATION
ION MOBILITY
MASS SPECTROSCOPY
MOISTURE
SPECTROSCOPY