Ics as dv 50

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)].

Carbohydrate analysis was performed on an ICS3000 DP liquid chromatography system (Dionex, Sunnyvale, CA, USA) equipped with a quaternary gradient pump (Dionex). The carbohydrates were separated on a CarboPac® PA100 pellicular anion-exchange column (4 mm×250 mm; Dionex) at 30 °C. An ICS AS-DV 50 autosampler (Dionex) was used for sample injection (injection volume for each sample was 25 μL). The mobile phase, consisting of 600 mM sodium hydroxide (A), 500 mM sodium acetate (B) and ultrapure water (C), was used according to the following linear gradient (flow rate, 0.7 mL/min): 0–5 min, 15% A, 85% C; 5.0–5.1 min, 15% A, 2% B, 83% C; 5.1–12.0 min, 15% A, 2% B, 83% C; 12.0–12.1 min, 15% A, 4% B, 81% C; 12.1–20.0 min 15% A, 4% B, 81% C; 20.0–20.1 min 20% A, 20% B, 60% C; 20.1–30.0 min 20% A, 20% B, 60% C. Before the analysis, the system was preconditioned with 15% A and 85% C for 15 min. The pulsed amperometric detector consisted of gold as the working electrode and Ag/AgCl as the reference one. Data were collected using Chromeleon software (20 ) and exported to Excel for further analysis.

For the quantification of sugars and sugar alcohols the HPAEC-PAD system was used. Carbohydrates were analyzed in pollen samples on a Carbo PacPA10 pellicular anion-exchange column (4 × 250 mm; Dionex, Sunnyvale, CA, USA) at 30 °C. Each sample (25 µL) was injected with an ICS AS-DV 50 autosampler (Dionex, Sunnyvale, CA, USA). Carbohydrates were eluted with a flow rate set to 0.7 mL/min, in gradient prepared from 600 mM sodium hydroxide (eluent A), 500 mM sodium acetate (eluent B), and ultrapure water (eluent C). The gradient program was as follows: 0.0–20.0 min, 15% A; 20.1–30.0 min, 20% A; 0.0–5.0 min, 0% B; 5.1–12.0 min, 2% B; 12.1–20.0 min, 4% B; and 20.1–30.0 min, 20% B. The calibration of carbohydrates was performed with standard solutions of sugars and sugar alcohols. Table 1 provides data on limit of detection (LOD), limit of quantification (LOQ), and recovery (R, %).