Structural elucidation of stress degradation products of ampicillin sodium by liquid chromatography/hybrid triple quadrupole linear ion trap mass spectrometry and liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry

2014 ◽  
Vol 28 (17) ◽  
pp. 1929-1936 ◽  
Author(s):  
Tao Li ◽  
Xuanlin Xu ◽  
Shan Fu ◽  
Juan Zhang ◽  
Kerong Zhang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Ion Trap ◽  
Degradation Products ◽  
Ion Trap Mass Spectrometry ◽  
Linear Ion Trap ◽  
Triple Quadrupole ◽  
Flight Mass Spectrometry ◽  
Stress Degradation ◽  
Quadrupole Linear Ion Trap

scholarly journals Phenolic Compounds in Different Barley Varieties: Identification by Tandem Mass Spectrometry (QStar) and NMR; Quantification by Liquid Chromatography Triple Quadrupole-Linear Ion Trap Mass Spectrometry (Q-Trap)

2010 ◽  
Vol 5 (3) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Kamilla Klausen ◽  
Anne G. Mortensen ◽  
Bente Laursen ◽  
Kim F. Haselmann ◽  
Birthe Møller Jespersen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Secondary Metabolites ◽  
Ion Trap ◽  
Principal Component ◽  
Ion Trap Mass Spectrometry ◽  
Linear Ion Trap ◽  
Triple Quadrupole ◽  
Positive Health ◽  
Quadrupole Linear Ion Trap

Barley (Hordeum vulgare) is an important cereal that has many applications; as a human food, in malt products and as livestock feed. The content of soluble health-promoting fibers, β-glucans, varies substantially among barley varieties. In the present study, the content of secondary metabolites with potential positive health effects in different high- and low-β-glucan barley varieties was studied. Five different flavanols were isolated and identified: (2 R,3 S)-catechin-7- O-β-D-glucopyranoside (1), prodelphinidin B3 (2), procyanidin B3 (3), (+)-catechin (4) and procyanidin B1 (5). Procyanidin B1 has never been reported in barley grains before. The compounds were identified using 1H NMR and quadrupolar time-of-flight mass spectrometry. A quantitative analytical method was developed for prodelphinidin B3, procyanidin B3 and (+)-catechin in liquid chromatography triple quadrupole-linear ion trap mass spectrometry and these compounds were quantified in all varieties, together with four phenolic acids: ferulic acid, vanillic acid, p-coumaric acid and p-hydroxybenzoic acid. Catechin was the compound that was present at the highest concentration in all varieties. The variation, between cultivars, in catechin concentration varied four fold. A Principal Component Analysis indicated no correlation between concentrations of β-glucan and secondary metabolites. Concentrations of catechin and prodelphinidin B3 were strongly correlated, whereas the concentration of procyanidin B3 was not correlated with that of catechin or prodelphinidin B3. Either two different enzymes could be responsible for the dimerization of prodelphinidin B3 and procyanidin B3, or the affinity of the enzyme could be different whether the dimerization is between two catechin units or between units of gallocatechin and catechin.

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