Ag agcl reference electrode

Determination of monosaccharide composition present in the purified CPS was performed, using a Thermo ScientificTMDionex™ ICS-6000 Ion Chromatography system, equipped with a gradient pump, an electrochemical detector with a gold electrode and an Ag/AgCl reference electrode (Thermofisher Scientific, Waltham, MA). A Thermo SceintificTMDionex™ CarboPac PA20 3 × 150 mm analytical column with a guard column was used for separation. Three elution buffers were used, which included 0.45-μm filtered, deionized water with a 18.5-MΩ-cm resistivity, 100-mM NaOH and 100-mM NaOH with 1-M NaOAc, running a custom gradient at 0.5-ml/min for a 30-min collection time. The CPS sample was hydrolyzed using 10-N trifluoro acidic acid (TFA) and heated at 121°C for 2 h to ensure hydrolysis of the polysaccharide to individual monosaccharides. The hydrolyzed sample was then cooled on ice, lyophilized, and suspended in the same initial volume of 0.45-μm filtered, deionized water with an 18.5-MΩ-cm resistivity. The reconstituted sample was subsequently injected onto the HPAEC-PAD system for analysis. Monosaccharide peak identity was verified via known retention times of a standard mixture of known monosaccharide composition. The reference mixture used for this study included glycerol phosphate (GroP), glycerol (Gro), rhamnose (Rha), glucosamine (GlcN), galactose (Gal), and glucose (Glc).

During a feeding cycle, samples were taken for COD, pH and ion chromatographic measurements. Following this, the reactors were refilled at the open circuit potential (OCP). Once the voltage stabilised, the reactors were polarised. During polarisation the change in cell current and voltage, as well as the anode and cathode potentials under polarisation (vs. a Ag/AgCl reference electrode), were recorded continuously using a data acquisition system (ADC 16, Pico Technology Ltd, UK). Polarization curves were recorded starting at OCP using a potentiostat (GillAC, ACM Instruments, UK) at a scan rate of 1 mV s^-1.
Anode and cathode potentials were monitored during cell polarisation using an Ag/AgCl reference electrode (Thermo Scientific, UK) placed in the anode chamber through a capillary using phosphate buffer (100 mM; pH 6.5) as electrolyte. The cathode potential were internal resistance (iR) corrected as the cathode potential had to be measured through the membrane.
The internal resistance was measured by electrochemical impedance spectroscopy using a potentiostat (Gillac, ACM Instruments). Impedance measurements were conducted at OCP over a frequency range of 30000 to 0.1 Hz with a sinusoidal perturbation of 10 mV amplitude.