N‐alkylpyridinium quaternization for assisting electrospray ionization of sterols in oil by quadrupole‐time of flight mass spectrometry

Abstract

The use of N-alkylpyridinium isotope quaternization method provided an alternative method for identifying the potential illegal cooking oil.

Charged tag founded in N-(1-chloroalkyl)pyridinium quaternization for quantification of fatty aldehydes

“…At the onset of this research, we designed several possible reagents to label fatty aldehydes. Inspired by the N-alkylpyridinium quaternization of fatty alcohols [38][39][40] in our previous work, we designed a three-component reaction that could specifically label fatty aldehydes (Fig 1). Pyridine large excess of reagent (10 µL of SOCl 2 and pyridine, about 10 5 equiv) was added to ensure complete derivatization.…”

“…It is well accepted that chemical addition of permanent charged group onto target compounds could efficiently facilitate their ionization in mass spectrometry [38][39][40][41][42]. A variety of charged derivatization reagents are available for fatty aldehydes, such as the Girard T [43,44] and P reagents [45], containing a quaternary ammonium and a pyridinium moiety, respectively.…”

Simple approach to derivatization of alcohols and phenols for the analysis by matrix(surface)‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

“…Steroid alcohols perform various physiological functions in living organisms and different mass spectrometric methods for their identification, quantification and profiling have been developed. Some recent papers describe new derivatization techniques for use with GC/MS, ESI‐MS, and MALDI‐TOFMS in the analysis of steroid alcohols. Application of non‐derivatization MALDI‐MS with DHB salts as matrices to sterol analysis has been tested as well …”

Coumarins as new matrices for matrix-assisted laser-desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric analysis of hydrophobic compounds

“…Chemical derivatization with quaternary or tertiary reagents is regularly used to enhance ionization efficiency and detection sensitivity in MALDI-MS analysis [17][18][19], but incurs costs in terms of time and complexity. We have also developed a simple N-alkylpyridinium isotope quaternization (NAPIQ) method for improving the detection sensitivity for steroids and fatty alcohols by MALDI-MS analysis [20][21][22]. Furthermore, conventional MALDI matrices, including 2,5-dihydroxybenzoic acid (DHB) and a-cyano-4-hydroxycinnamic acid (CHCA), have hydrophilic properties and low affinity for hydrophobic compounds [23,24].…”