Ultraflextreme tof instrument

MALDI MS: The raw samples withdrawn directly from the polymerization mixture were dissolved in a 1/1 W/A mixture to a concentration of 10 mg/mL. Afterward, the samples were mixed with a matrix solution (saturated solution of α-cyano-hydroxycinnamic acid in W/A mixture 1/1 v/v) in a ratio of 1/100 (v/v). One microliter of this mixture was deposited on a polished steel MALDI target. Mass spectra of polymers were measured on an UltrafleXtreme TOF instrument (Bruker, Bremen, Germany), equipped with a 355 nm smart beam-2 laser, capable of 1 kHz pulsing frequency. Mass spectrometer operation and spectra processing were performed by using FlexControl 3.3 software (Bruker, Bremen, Germany). The ionization laser power was adjusted to just above the threshold to produce charged species. More than 10,000 spectra were collected for each sample.
¹H NMR CDLA: The proton NMR spectra were recorded on a Bruker Avance DRX 400 MHz spectrometer equipped with a 5 mm QNP direct detection probe and z-gradients. The spectra were recorded in DMSO-d6, at room temperature. The chemical shifts are reported as δ values (ppm) relative to the solvent residual peak. The obtained spectra coincided with the previously published ones [27 (link)].

The raw samples withdrawn directly from the polymerization mixture were dissolved in a 1/1 water/acetonitrile mixture to a concentration of 10 mg/mL. The liquid chromatography fractions were used as such. Samples were mixed with a matrix solution (saturated solution of α-cyano-hydroxy-cynamic acid in water/acetonitrile mixture) in a ratio of 1/100 (v/v). One microliter of this mixture was deposited on a polished steel MALDI target (Bruker, Bremen, Germany). Mass spectra of polymers were measured on an UltrafleXtreme TOF instrument (Bruker) equipped with a 355-nm smartbeam-2 laser capable of a pulsing frequency of 1 kHz. The mass spectrometer was operated by FlexControl 3.3 software (Bruker). Acquired spectra were processed by FlexAnalysis 3.3 software (Bruker). The ionization laser power was adjusted just above the threshold in order to produce charged species. The mass spectra were collected in an amount above 10,000 spectra for each sample. The fragmentation spectra were obtained in LIFT mode and 20,000 spectra were collected for each MS/MS spectrum. The samples were spiked with the desired cationization agent as 0.1 M solution in water (LiI, NaI, and KCl).

Polymer samples after evaporation of solvent were dissolved in THF to a concentration of 10 mg/mL. Samples were mixed with a matrix solution 1,8,9-antracenetriol or dithranol (Sigma-Aldrich, Merck, Darmstadt, Germany). (10 mg/mL in a ratio of 1/100 (v/v). 1 μL of this mixture were deposited on polished steel MALDI target (Bruker, Bremen, Germany). Mass spectra of polymers were measured on UltrafleXtreme TOF instrument (Bruker, Bremen, Germany), equipped with a 355 nm smartbeam-2 laser capable of pulsing frequency 1 kHz. Mass spectrometer was operated by FlexControl 3.3 software (Bruker, Bremen, Germany). Acquired spectra were processed by FlexAnalysis 3.3 software (Bruker, Bremen, Germany). The ionization laser power was adjusted just above the threshold in order to produce charged species. The mass spectra were collected in amount of above 10,000 spectra. The fragmentation spectra of the selected MS peaks were acquired in LIFT mode, setting the laser power just above the threshold to obtain parent ions fragmentation.