PolyTools 2.0

PolyTools can directly use peak lists created with flexAnalysis or other Bruker programs, or from other sources. PolyTools will automatically determine the monomer, end groups and cation that produced the measured mass spectrum. If isotopes are resolved in the peak list, lines belonging to the isotope distribution are identified and can be reduced to a monoisotopic series. For every series, the average molecular weights M_n and M_w, the dispersity Đ_M and degree of polymerization are determined and suggestions for the end groups are made. New stick spectra calculated from all these data are displayed, together with the experimental spectrum for comparison.

Further, in PolyTools version 2.0, a new Kendrick plot function is implemented to give users a graphical overview of peak series observed in a spectrum, and to be helpful to organize and interpret peak series in spectra especially of complex mixture samples.     

From dissolving of the sample until PolyTools displays the results characterizing the analyzed polymer takes only a few minutes. Therefore, PolyTools in combination with the mass spectrometric analysis with a MALDI time of flight mass spectrometer is the ideal combination for getting fast and reliable information on incoming goods. Average molecular weights M_n and M_w as well as the observed end group combination can directly be compared with the reference compound.   

Complex mixtures of polymers like the non-ionic surfactant Tween requires a different visualization of the spectra: a simple simulation of found oligomeric ion series is not sufficient in this case. PolyTools offers the possibility to show the spectra in the form of Kendrick Mass Defect (KMD) plots and resolution enhanced KMD plots. For mass spectra obtained on instruments with a low resolving power or from the higher mass range where only oligomeric resolution can be achieved, PolyTools contains the remainders of Kendrick Mass (RKM) plot. This can be applied to increase the mass tolerance compared to regular and resolution enhanced KMD plots. Even mass range over 10 kDa or TOF/TOF spectra can be reasonably visualized.

For the end group analysis PolyTools 2.0 offers two plots using the remainder of Nominal Kendrick Mass (RNKM): KMD - RNKM and RKM – RNKM. As a part of PolyTools 2.0 the PolymerTable editor allows the convenient setup of monomer units, end groups and cations in tables that serve as databases for the spectrum interpretation in PolyTools 2.0. 

In an MS experiment intact, oligomeric species are detected. The observed masses are composed of a certain number of monomer units, the ionizing cation, and the masses of the two end-groups. Therefore, a single end group analysis cannot be obtained this way. An MS/MS experiment can provide this information as every fragment only carries one singe end group [1].  

Another application where MS/MS can give a deeper insight into the structure of a polymer sample is the determination of the block length in a block copolymer [2].

[1] Knop et al.; Systematic MALDI‐TOF CID Investigation on Different Substituted mPEG 2000; Macromol. Chem. Phys. 2010, 211, 677–684

[2] Weidner et al.; A novel software tool for copolymer characterization by coupling of liquid chromatography with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; Rapid Commun. Mass Spectrom. 2007; 21, 2750–2758