2-Hydrazinoquinoline: A Reactive Matrix for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry to Detect Gaseous Carbonyl Compounds

Abstract

The sensitivity, range of applications, and reaction mechanism of 2-hydrazinoquinoline as a reactive matrix for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were examined. Using a reaction chamber (125L) equipped with a stirring fan and a window for moving the MALDI-MS plate and volatile samples in and out, the sensitivities of 2-hydrazinoquinoline to gaseous aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and n-butyraldehyde) and ketones (acetone, methyl ethyl ketone, and methyl isobutyl ketone) were determined to be at least parts per million (ppm) levels. On the other hand, carboxylic acids (formic acid, acetic acid, propionic acid, and butyric acid) and esters (ethyl acetate, pentyl acetate, isoamyl acetate, and methyl salicylate) could not be detected by 2-hydrazinoquinoline in MALDI-MS. In addition to 2,4-dinitrophenylhydrazine, a common derivatization reagent for analyzing carbonyl compounds quantitatively in gas chromatography and liquid chromatography, the dissolution of 2-hydrazinoquinoline in an acidic solution, such as trifluoroacetic acid, was essential for its function as a reactive matrix for MALDI- MS.

Rapid Determination of Six Low Molecular Carbonyl Compounds in Tobacco Smoke by the APCI-MS/MS Coupled to Data Mining

“…To overcome the quantitative difficulties, more structure information should be obtained to distinguish acetone/propionaldehyde and butanone/butyraldehyde. Due to the different functional groups or positions in the molecule, the analysis of carbonyl isomers could be performed by chromatography coupled with derivatization [24, 25]. However, derivatization methods usually involved multistep sample preparation and long analytical period.…”

MALDI Matrices for the Analysis of Low Molecular Weight Compounds: Rational Design, Challenges and Perspectives

“…Several other hydrazide-or hydrazine-containing compounds were also reported as reactive matrices for gaseous aldehydes containing carbonyl groups (e. g., formaldehyde, acetaldehyde and propionaldehyde) [91] as well as for ketones (e. g., acetone, methyl ethyl ketone, and methyl isobutyl ketone). [92] Analytes carrying amino functions can be targeted by pyrylium cations, six-membered aromatic heterocycles containing a positively charged oxygen atom. Pyrylium reacts with primary amines to yield the corresponding pyridinium cations, a conversion which often takes place already at room temperature under mild conditions.…”

“…DNHP converts the aldehydes into the corresponding hydrazones, which are easily identified, lowering the detection limit and giving mass spectra with low background noise. Several other hydrazide‐ or hydrazine‐containing compounds were also reported as reactive matrices for gaseous aldehydes containing carbonyl groups (e. g., formaldehyde, acetaldehyde and propionaldehyde) [91] as well as for ketones (e. g., acetone, methyl ethyl ketone, and methyl isobutyl ketone) [92] …”

Biofluid Metabolic Profiling for Lung Cancer Screening via Reactive Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

“…Carbonyl compounds such as aldehyde and ketone molecules are difficult to be ionized and analyzed by MS. As reported previously, 2-HQ acts as a reactive matrix that can be used in both positive and negative ion mode for MALDI−MS analysis of carbohydrates and gaseous carbonyl compounds. 23,24 In the present study, derivative analysis of aldehyde and ketone molecules in serum and urine samples from LC patients and healthy controls (HCs) has been achieved using 2-HQ as the reactive MALDI matrix. In addition, various metabolites such as organic acids, alkaloids, and lipids can also be directly detected simultaneously.…”