Dionex ics 5000 capillary hpic system

The monomeric sugar composition of the extracts was determined according to Demuth et al. (15 (link)) by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) after hydrolysis with trifluoracetic acid. The 10-mg sample materials were hydrolyzed with 2.5 ml 2 M TFA for 4 h at 100°C. The HPAEC-PAD separation was based on a procedure by Hardy et al. (31 (link)) and Rohrer et al. (32 (link)) with modifications. A Dionex™ ICS-5000+ Capillary HPIC™ System with a Dionex™ CarboPac™ PA1 IC column (Thermo Fischer Scientific AG, Basel, Switzerland) maintained at 26°C was used. The injection volume was 10 μl and the flowrate was 1 ml/min. Eluent (A) consisted of water and eluent (B) had 200 mM of NaOH. The gradient started with 92% (A) for 20 min. After 20 min, the gradient was changed to 100% (B) for 10 min, and finally re-equilibrated for 8 min with 92% (A). For the pulsed amperometric detection, replaceable gold electrodes were used in waveform A adapted from the Dionex technical note 21. All samples were measured in quintuplicates. L-(+)-arabinose and D-(+)-xylose as well as D-(+)-glucose and D-(+)-galactose were externally calibrated using a 13-point calibration from 1.25 to 100 μg/ml with 10 μg/ml of D-(–)-sorbitol as internal standard. Data processing was done in Chromeleon 7 (Thermo Fischer Scientific AG, Basel, Switzerland).

Anion exchange chromatography-tandem mass spectrometry was performed using a Dionex ICS-5000+ Capillary HPIC system (Thermo Scientific) coupled to a Q Exactive hybrid quadrupole-Orbitrap mass spectrometer (Thermo Scientific) as described (Walsby-Tickle et al., 2020 (link)).