Multi-stage Mass Spectrometry of Poly(vinyl pyrrolidone) and Its Vinyl Succinimide Copolymer Formed upon Exposure to Sodium Hypochlorite

Abstract

e degradation routes of poly(vinyl pyrrolidone) (PVP) exposed to sodium hypochlorite (bleach) have been previously investigated using chemical analyses such as infrared spectroscopy. So far, no reports have proposed mass spectrometry (MS) as an alternative tool despite its capability to provide molecular and structural information using its single stage electrospray (ESI) or matrix assisted laser desorption ionization (MALDI) and multi stage (MS n ) con gurations, respectively. e present study thus reports on the characterization of PVP a er its exposure to bleach by high resolution MALDI spiralTOF-MS and Kendrick mass defect analysis providing clues as to the formation of a vinyl pyrrolidone/vinyl succinimide copolymeric degradation product. A thorough investigation of the fragmentation pathways of PVP adducted with sodium and proton allows one main route to be described-namely the release of the pyrrolidone pendant group in a charge remote and charge driven mechanism, respectively. Extrapolating this fragmentation pathway, the oxidation of vinyl pyrrolidone into vinyl succinimide hypothesized from the single stage MS is validated by the detection of an alternative succinimide neutral loss in lieu of the pyrrolidone release in the ESI-MS n spectra of the aged PVP sample. It constitutes an example of application of multi-stage mass spectrometry for the characterization of the degradation of polymeric samples at a molecular level.

Application of a novel cyclic ion mobility‐mass spectrometer to the analysis of synthetic polymers: A preliminary evaluation

“…The higher m/z species, observed in both the m/z 554.33 product ion spectrum and the composite product ion spectrum, are expected since the precursor ion had already been identified as being multiply charged (4+ charge, as seen in spectrum B, Figure ) and therefore the higher m/z species are ions with the same mass, m , but a lower charge state, z , than the precursor ion: doubly charged in the case of m/z 1085.65 and triply charged in the case of m/z 731.45 illustrated by the inset spectra for the clusters containing those ions in Figures A and B. In these specific cases, the mass difference appears to indicate the removal of sodium cations from the precursor ion rather than fragmentation of the polymer structure itself, as has been noted elsewhere in the literature . This was deduced by calculating the differences between the observed ions after taking account of the charge state: 1085.65 × 2 = 2171.3 ( m 1 ) and 731.45 × 3 = 2194.35 ( m 2 ), Δ m ( m 2 – m 1 ) = 23.05.…”

Ultraviolet photo-oxidation of polyvinylpyrrolidone (PVP) coatings on gold nanoparticles

“…We speculate there is formation of a poly(vinyl succinimide) (PVS) product, which has been observed recently in the literature as a product of PVP 3-mer oxidized through other synthetic methods. 44 Since a PVS reference compound was not commercially available, the FTIR spectrum is presented for PSI as an imide reference and exhibits the two C=O stretching peaks representative of imides, similarly to the two peaks observed for the PVP transformation product.…”

“…Together, the ATR-FTIR and XPS measurements demonstrate oxidation of the amide group in the pyrrolidone ring of PVP to a succinimide group consistent with a PVS chemical structure shown in Figure 3b and consistent with intermediate oxidation products reported previously for pure PVP. 27, 28, 44 For chemical mechanisms, the reader is referred to pure PVP studies proposing oxidation to imides via formation of hydroperoxides. 27–29 PVP does not absorb UV-visible light at wavelengths > 300 nm, so it was previously speculated that impurities in the pure PVP samples initiated photooxidation.…”

Improving the Resolution of Kendrick Mass Defect Analysis for Polymer Ions with Fractional Base Units

“…Data points have been peak-picked from the mass spectra using an automated procedure implemented in mMass with no deisotoping and a relative intensity threshold set at 5%. The accurate mass measurements of ions on the IUPAC scale were converted to KMs, NKMs and KMDs according to Contrary to the previous reports, 20 – 22 , 26 ) the base unit in the present article is a fraction of the repeat unit noted (repeat unit)/ X with the divisor X being an integer ranging from 1 to 10 (10 has been arbitrarily chosen for the sake of simplicity). While the value of X is increasing, the value of NKM is departing from the actual m / z value.…”