Dionex ics 3000

A tailings pond water sample (designated TPW) was collected from a Syncrude test pit (GIS 57.0380885, −111.5407123) courtesy of Warren Zubot (Syncrude). The test pit was excavated in 1993 and filled with aged recycled water from the Mildred Lake Settling Basin (MLSB). A second tailings pond water sample (designated 2m) was supplied by L. Gieg (University of Calgary) and collected at a water depth of 2 m from a Suncor tailings pond (GIS 56.9923073, −111.4979146).
For ion chromatography, environmental samples were diluted 10-fold in MilliQ water and filtered through a GF/F filter (Whatman) by vacuum. Samples were analyzed using an ICS-3000 Dionex. For cation analysis, the eluent was 20 mM methyl sulfonic acid run at a flow rate of 1 ml min⁻¹ for 30 mins on a Dionex Ionpac 4-mm column (column temperature, 30°C). The eluted cations were detected with a CSRS 300 4-mm Suppressor onto a conductivity cell detector. For the anion analysis, the eluent was MilliQ water and 100 mM KOH. Potassium hydroxide was run on a gradient with a flow of 0.25 ml min⁻¹. This was run through an Ionpac AS 18 2-mm column onto a conductivity cell detector. For total organic carbon (TOC) analysis, samples were measured using a Shimadzu TOC-VCHS pyrolyser fitted with an SSM 5000A solid sample module and running TOC-Control V software v. 2.00.

As reported by previous study, short chain fatty acid (SCFA) concentrations in ileal digesta were detected by using an ion chromatographic method (Liu et al., 2017 (link)). About 0.5 g of ileal digesta sample was mixed with 8 ml of distilled water, and after 30 min of ultrasonic treatment, the mixture was centrifuged at 8,000 × g for 10 min to achieve the supernatant. We filtered the diluted supernatant using a 0.22 μm filter and finally injected the supernatant into a high-performance ion chromatograph (ICS 3000 Dionex, United States). SCFAs were separated by an AG11 guard column and an AS11 analytical column under the gradient condition (0–5 min, 0.8–1.5 mm; 5–10 min, 1.5–2.5 mm; and 10–15 min, 2.5 mm); the flow rate was 1.0 ml/min. The gradient was carried out with potassium hydroxide.

Ileal and colonic digesta samples (0.5 g) were weighed into a 10 mL polypropylene tube and 8 mL of deionized water was added. After using an ultrasonic bath for 30 min, the mixture was centrifuged at 8000 rpm for 10 min. The suspension was diluted (1:50) with water and filtered through a 0.22 μm filter. A 25 µL sample solution was extracted and analyzed for the VFA, including acetic acid, propionic acid, and butyric acid by a HPLC (ICS-3000 Dionex, Sunnyvale, CA, USA), as described by Liu et al. [15 (link)].

The system for ion chromatography, DIONEX ICS 3000 (Dionex, Sunnyvale, CA, USA), consisting of a quaternary pump (Dionex, Sunnyvale, CA, USA), was equipped with autosampler ICS AS-DV 50 (Dionex, Sunnyvale, CA, USA) and coupled to a pulsed amperometric detector with a gold-working electrode and Ag/AgCl reference electrode. Carbohydrates were separated on a Carbo Pac^®PA100 high-performance anion-exchange column (4 × 250 mm) (Dionex, Sunnyvale, CA, USA) set to 30 °C. The mobile phase consisted of 600 mM sodium hydroxide, 500 mM sodium acetate, and ultrapure water, and the composition was changed during the time of analysis, as reported in detail in our previous work [41 (link)].

Samples for carbohydrate and acid-insoluble lignin content analysis were prepared using a standard NREL two-stage acid hydrolysis protocol [28 ]. Acid hydrolysis generates soluble sugars and acid-insoluble lignin residues, where the later was dried overnight at 105 °C in an oven (Heratherm oven, Thermo Scientific, MA, USA) and weighed to obtain the acid-insoluble lignin (Klason lignin) content. The soluble sugars were analyzed for carbohydrate constituents by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) (Dionex ICS-3000, Dionex, Sunnyvale, CA, USA). Separation of soluble sugars was achieved utilizing a CarboPac-PA1 2 × 250 mm analytical column equipped with a CarboPac PA1 2 × 50 mm guard column (both from Dionex, Sunnyvale, CA), operated at 30 °C, with Milli-Q water as a mobile phase with a flow rate of 0.250 mL/min. The total run time was 35 min. External calibration curves were established using the standard solutions of arabinose, galactose, glucose, mannose, and xylose. The standard solutions were prepared from their corresponding monosaccharide (> 99%) obtained from Sigma-Aldrich.

Volatile acids, such as formic acid, acetic acid, propionic acid, and so on, were analyzed via ion-exchange chromatography on a DIONEX ICS-3000 (Dionex Corporation, Sunnyvale, CA, United States). Briefly, the samples after fermented with three starters were filtered through Dionex OnGuard^TM II RP and H cartridge (Thermo, Sunnyvale, CA, United States) to remove interfering substances and was loaded into the instrument according to the instructions (Zhang and He, 2010 ). Volatile acids in samples were the sum of the content of each acid calculated with the standard solution.