Analysis of underivatized oligosaccharides by liquid chromatography/electrospray ionization tandem mass spectrometry with post‐column addition of formic acid

Abstract

Underivatized oligosaccharides were analyzed by electrospray ionization (ESI) using a linear ion trap mass spectrometer in the negative ion mode with post-column addition of an aqueous solution of formic acid. Under these conditions all oligosaccharides showed the presence of the corresponding formate adduct [M + HCOO](-) with high intensity and easy subsequent low-energy collision-induced dissociation (CID) fragmentation using successive MS(n) experiments. A careful examination of the mass spectra obtained from these MS(n) experiments pointed out some significant differences useful to identify and quantify the single components in mixtures of coeluted disaccharides. This new sensitive and rapid method was successfully applied to the quantification of oligosaccharides in some juices minimizing sample handling.

Chemical profile, antioxidant, and enzyme inhibitory properties of two Scutellaria species: S. orientalis L. and S. salviifolia Benth

“…Compound 1 was characterized as a disaccharide. Typical fragment ions from hexoses are observed at m / z 179, 161, 143, 131, 119, and 113 . Compounds 6 , 8 , 16 , and 19 also displayed MS fragment ions typical of hexoside moieties, but they could not be fully characterized, so they are tentatively characterized as saccharide derivatives.…”

Anomeric discrimination and rapid analysis of underivatized lactose, maltose, and sucrose in vegetable matrices by U‐HPLC–ESI‐MS/MS using porous graphitic carbon

“…The aim of this work was the setting and optimization of a selective and practical LC–MS method for the analysis of lactose in vegetable matrices, in the presence of the other common interfering disaccharides maltose and sucrose. Prompted by recent work where good sensitivity was obtained in negative ion mode by monitoring the formate adduct [M + HCOO] − , obtained by post‐column addition of formic acid/ammonium formate,17 we set out similarly but aimed at avoiding post‐column additions. Particularly, we aimed at improving the chromatography with respect of more conventional approaches, so as to achieve complete resolution of the disaccharides.…”

“…Unfortunately, however, it does not allow determining the actual content of each disaccharide when they are present in a mixture, in the absence of good chromatographic resolution. Co‐elution of lactose and maltose or lactose and sucrose is often encountered,16, 17 and many discussions regarding the separation of disaccharides by liquid chromatography can be found in the literature. Most of them involve the use of aminic‐phase columns, which, however, do not allow the separation of anomeric forms of reducing sugars17, 18 and suffer from important pH effects.…”

“…Co‐elution of lactose and maltose or lactose and sucrose is often encountered,16, 17 and many discussions regarding the separation of disaccharides by liquid chromatography can be found in the literature. Most of them involve the use of aminic‐phase columns, which, however, do not allow the separation of anomeric forms of reducing sugars17, 18 and suffer from important pH effects. Besides the use of cyclodextrins‐based special columns,19, 20 which often require complex elution techniques, the use of columns based on porous graphitic carbon (PGC) allows the separation of disaccharides, including their anomeric forms, working in conditions of reversed‐phase HPLC with post‐column derivatization and fluorescence detection 21…”

High Triterpenic Acids Production in Callus Cultures from Fruit Pulp of Two Apple Varieties

“…As reported in Fig. , both spectra exhibited three zones: the first, from m/z 150 to 350, showed quasi‐molecular ions at m/z 179 [M‐H] − , 215 and 217 [M + Cl] − and 225 [M + HCOO] − derived from a monosaccharide (glucose and/or fructose), and at m/z 341 [M‐H] − from sucrose as confirmed by MS n experiments (Verardo et al , ). The [M‐H] − ions at m/z 455, 469, 471, 485 and 487 characterised the second zone of the spectra.…”