title: Biogenic aldehyde determination by reactive paper spray ionization mass spectrometry.
abstract: Ionization of aliphatic and aromatic aldehydes is improved by performing simultaneous chemical derivatization using 4-aminophenol to produce charged iminium ions during paper spray ionization. Accelerated reactions occur in the microdroplets generated during the paper spray ionization event for the tested aldehydes (formaldehyde, n-pentanaldehyde, n-nonanaldehyde, n-decanaldehyde, n-dodecanaldehyde, benzaldehyde, m-anisaldehyde, and p-hydroxybenzaldehyde). Tandem mass spectrometric analysis of the iminium ions using collision-induced dissociation demonstrated that straight chain aldehydes give a characteristic fragment at m/z 122 (shown to correspond to protonated 4-(methyleneamino)phenol), while the aromatic aldehyde iminium ions fragment to give a characteristic product ion at m/z 120. These features allow straightforward identification of linear and aromatic aldehydes. Quantitative analysis of n-nonaldehyde using a benchtop mass spectrometer demonstrated a linear response over 3 orders of magnitude from 2.5 ng to 5 μg of aldehyde loaded on the filter paper emitter. The limit of detection was determined to be 2.2 ng for this aldehyde. The method had a precision of 22%, relative standard deviation. The experiment was also implemented using a portable ion trap mass spectrometer.
authors: Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors: Soumabha
authors: S
authors: Bag
authors: Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors: P I
authors: PI
authors: Hendricks
authors: Centre for Analytical Science, Loughborough University, Loughborough, Leicestershire, UK.
authors: J C
authors: JC
authors: Reynolds
authors: Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA. Electronic address: cooks@purdue.edu.
authors: R G
authors: RG
authors: Cooks
keywords: Ambient mass spectrometry; Amines; Chemical derivatization; In-situ analysis; Mannich reaction; Reactive ionization; Trace analysis