Separation and characterization of unknown impurities in rutin tablets using trap‐free two‐dimensional liquid chromatography coupled with ion trap/time‐of‐flight mass spectrometry

Abstract

RationaleA new high‐performance liquid chromatography method was developed for the determination of impurities in rutin tablets to improve on the method of the official monograph in national drug standards. Five impurities in rutin tablets were characterized using trap‐free two‐dimensional liquid chromatography coupled with ion trap/time‐of‐flight mass spectrometry (2D‐LC/IT‐TOFMS) in both positive and negative ion modes of electrospray ionization.MethodsIn the first dimension, the LC column was a Thermo Acclaim 120™ C18 (4.6 mm × 250 mm, 5 μm), and the mobile phase was composed of 0.1 M sodium dihydrogen phosphate aqueous solution (pH adjusted to 4.4 with phosphoric acid) and acetonitrile (80:20, v/v). In the second dimension, the column was a Shimadzu Shim‐pack GISS C18 (50 mm × 2.1 mm, 1.9 μm), and the mobile phase was composed of 10 mM ammonium formate solution and methanol.ResultsThe structures of five impurities in rutin tablets were deduced based on the MS n data in both positive and negative ion modes, in which two impurities were unknown. Impurity 1, impurity 2 and impurity 3 were proposed as flavonol 3,7‐di‐O‐glycoside, flavonol mono‐O‐triglycoside and quercetin 3‐O‐glycoside, respectively, and impurity 4 and impurity 5 were proposed as kaempferol 3‐O‐rhamnosylglucoside and isorhamnetin 3‐O‐rhamnosylglucoside, respectively.ConclusionsThe method established in this study was simple and reliable for the routine quality control of rutin tablets. The contradiction between non‐volatile salt mobile phase and mass spectrometry was solved by means of a multiple heart‐cutting 2D‐LC approach and on‐line desalination technology. Five impurities were separated and characterized. These results provide a scientific basis for further improving the national drug standard of rutin tablets.

Quality of African moringa ( Moringa stenopetala ) leaf samples by liquid chromatography of phenolics, loss on drying and ash content

“…The deprotonated molecule fragmented into the product ions at m/z 447 following the loss of a rhamnosyl moiety and a predominant ion at m/z 285 (= [M – H − 308] − ) by cleavage of the 3‐O glycosidic bond, indicating the loss of the disaccharide rutinose (combined loss of glucosyl and rhamnosyl moiety). This is characteristic for the flavonol called kaempferol (Farias & Mendez, 2014; Wang et al, 2020). MS 3 of the ion at m/z 285 lost 29 u (H + CO) to m/z 256, with further loss of CO (28 u ) yielding the ion at m/z 228 (Figure 4d).…”

Separation and characterization of impurities and isomers in cefpirome sulfate by liquid chromatography/tandem mass spectrometry and a summary of the fragmentation pathways of oxime‐type cephalosporins

“…Figure 1 shows the chromatogram of cefpirome sulfate in the first dimension. In order to be suited to LC/MS analysis, the mobile phase in the second dimension must be volatile, and 10 mM ammonium formate solution and methanol were selected as the mobile phases 12 …”

“…In order to be suited to LC/MS analysis, the mobile phase in the second dimension must be volatile, and 10 mM ammonium formate solution and methanol were selected as the mobile phases. 12 3.2 | Characterization of cefpirome and impurities in cefpirome sulfate Table 1 presents…”

Metabolites Analysis of Anti-Myocardial Ischemia Active Components of Saussurea involucrata Based on Gut Microbiota—Drug Interaction

“…From the highresolution mass spectra obtained by IT-TOF, we make the following summary of its mass fragmentation pathway. The ion with m/z of 463.0440 was produced by losing 1 rhamnose from the molecular ion ([M − H-C 6 H 10 O 4 ] − , m/z = 463.0440) [32]. The subsequent ion with m/z of 301.0348 was generated from the loss of 1 glucose in the ion of m/z = 463.0440 ([M − H-C 6 H 10 O 4 -C 6 H 10 O 5 ] − , m/z = 301.0348) [33]; the latter continued to lose the B ring on the flavonoid skeleton to generate the ion of [M − H-C 6 H 10 O 4 -C 6 H 10 O 5 -C 7 H 6 O 2 ] − with m/z = 178.9948 [32], and the ion with m/z = 178.9948 continued to lose the C ring to produce an ion with m/z = 151.0035 [32].…”

“…The ion with m/z of 463.0440 was produced by losing 1 rhamnose from the molecular ion ([M − H-C 6 H 10 O 4 ] − , m/z = 463.0440) [32]. The subsequent ion with m/z of 301.0348 was generated from the loss of 1 glucose in the ion of m/z = 463.0440 ([M − H-C 6 H 10 O 4 -C 6 H 10 O 5 ] − , m/z = 301.0348) [33]; the latter continued to lose the B ring on the flavonoid skeleton to generate the ion of [M − H-C 6 H 10 O 4 -C 6 H 10 O 5 -C 7 H 6 O 2 ] − with m/z = 178.9948 [32], and the ion with m/z = 178.9948 continued to lose the C ring to produce an ion with m/z = 151.0035 [32]. Based on peak 4 and its molecular weight and mass spectral fragmentation pathway, and further comparison with the standard, we suspected that peak 4 was rutin.…”