Application of matrix-assisted laser desorption/ionization to on-line aerosol time-of-flight mass spectrometry

✍ Scribed by M. A. Stowers; A. L. van Wuijckhuijse; J. C. M. Marijnissen; B. Scarlett; B. L. M. van Baar; Ch. E. Kientz

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 65 KB
• Volume: 14
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(20000530)14:10<829::aid-rcm951>3.0.co;2-3

✦ Synopsis

Matrix-assisted laser desorption/ionization (MALDI) mass spectra were obtained from single biological aerosol particles using an aerosol time-of-flight mass spectrometer (ATOFMS). The inlet to the ATOFMS was coupled with an evaporation/condensation flow cell that allowed the aerosol to be coated with matrix material as the sampled stream entered the spectrometer. Mass spectra were generated from aerosol composed either of gramicidin-S or erythromycin, two small biological molecules, or from aerosolised spores of Bacillus subtilis var niger. Three different matrices were used: 3-nitrobenzyl alcohol, picolinic acid and sinapinic acid. A spectrum of gramicidin-S was generated from approximately 250 attomoles of material using a molar ratio of 3-nitrobenzyl alcohol to analyte of approximately 20:1. A single peak, located at 1224 Da, was obtained from the bacterial spores. The washing liquid and extract solution from the spores were analyzed using electrospray mass spectrometry and subsequent MS/MS product ion experiments. This independent analysis suggests that the measured species represents part of the B. subtilis peptidoglycan. The on-line addition of matrix allows quasi-real-time chemical analysis of individual, aerodynamically sized particles, with an overall system residence time of less than 5 seconds. These results suggest that a MALDI-ATOFMS can provide nearly real-time identification of biological aerosols. Copyright 2000 John Wiley & Sons, Ltd.