The Kendrick analysis for polymer mass spectrometry

Abstract

The mass spectrum of a polymer often displays repetitive patterns with peak series spaced by the repeating unit(s) of the polymeric backbones, sometimes complexified with different adducts, chain terminations, or charge states. Exploring the complex mass spectral data or filtering the unwanted signal is tedious whether performed manually or automatically. In contrast, the now 60‐year‐old Kendrick (mass defect) analysis, when adapted to polymer ions, produces visual two‐dimensional maps with intuitive alignments of the repetitive patterns and favourable deconvolution of features overlaid in the one‐dimensional mass spectrum. This special feature article reports on an up‐to‐date and theoretically sound use of Kendrick plots as a data processing tool. The approach requires no prior knowledge of the sample but offers promising dynamic capabilities for visualizing, filtering, and sometimes assigning congested mass spectra. Examples of applications of the approach to polymers are discussed throughout the text, but the same tools can be readily extended to other applications, including the analysis of polymers present as pollutants/contaminants, and to other analytes incorporating a repetitive moiety, for example, oils or lipids. In each of these instances, data processing can benefit from the application of an updated and interactive Kendrick analysis.

Phytosterols and Novel Triterpenes Recovered from Industrial Fermentation Coproducts Exert In Vitro Anti-Inflammatory Activity in Macrophages

“…Further LC-QTOF analyses showed only one eluting peak, confirming the Gaussian distribution of ions ( Figure S8 ). This agrees with the presence of oligomers, suggesting that this compound can be a polymer [ 33 ]. In fact, since FDR is a by-product of the distillation of β-farnesene (PR 15), this polymer may arise during the process.…”

Advanced analysis of oligomeric proanthocyanidins: latest approaches in liquid chromatography and mass spectrometry based analysis

“…Whereas the mass defect-i.e., the difference between the exact and the nominal mass-is unequal within a homologue series of a polymer, the Kendrick mass defect-i.e., the difference between the exact and nominal Kendrick mass-remains constant. It is necessary to note, that this definition is rather general, but sufficient for PAC analysis, while a more differentiated definition can be found in Fouquet et al (2019) (Fouquet 2019). By attributing ions of every polymer class to a specific KMD, molecular ions can be compared and classified.…”

Mass Spectral Filtering by Mass-Remainder Analysis (MARA) at High Resolution and Its Application to Metabolite Profiling of Flavonoids

“…Besides the MDF process, the Kendrick Mass Defect (KMD) [19] and related methods [20][21][22] (Re-KMD) are applied for the analysis of complex mass spectra, however, it is not widespread in metabolomics.…”