Ekspert ultra lc100 xl

Flavonoids were identified using an ABSciex triple Quad 4500 mass spectrometer equipped with an electrospray (TurboV) interface coupled to an Eksigent Ekspert Ultra LC100 with an Ekspert Ultra LC100-XL autosampler system (AB/Sciex Concord, ON, Canada). Chromatographic separation occurred using a gradient elution with (A) 0.1% formic acid and (B) methanol as the mobile phase as follows: 0–1 min, 15% B; 1–17 min, 15–100% B; 17–21 min 100–100% B; 21–22 min, 100–15% B; and 22–25 min, 15–15% B. The instrument was operated using an injection volume of 50 μL, a flow rate of 0.5 mL/min, and an end-capped column (LiChrospher 100 RP-18; 125 mm × 4 mm i.d., 5 μm; Merck, Darmstadt, Germany) maintained at 50 °C. Calibration curves for quantification were constructed using commercially available standards. Table 1 shows the parameters used for compound identification.

To separate and quantify products of alanine VvROMT variants reactions, we used an Eksigent Ekspert Ultra LC100-XL (AB/Sciex, Concord, ON, Canada) coupled with a TripleQuadTM 4500 mass spectrometer system. The chromatographic separation was carried out using the column Inersil ODS-4 (3 μm, 2.1 × 100 mm) (GL Sciences) at 40 °C and a gradient elution of 0.1% formic acid in water (A) and acetonitrile (B) as a mobile phase. The gradient was programmed as follows: 0–2 min, 30% B; 2–4 min, 50% B; 4–5.5 min, 70% B; and 5.5–6.5 min, 30% B. The injection volume was 10 µL, and the flow rate was kept at 0.5 mL/min.
For MS/MS analysis, detection conditions were the following: electrospray ionization (ESI) in negative mode and a multiple reaction monitoring (MRM) mode were selected. The optimized parameters applied to each compound are presented in (Table S5). The quantification of substrate and products was carried out according to a calibration curve with the standards resveratrol, pinostilbene, and pterostilbene, in a concentration range between 0.05 to 3.5 mg L⁻¹ (Figure S3) dissolved directly in 80 % (v/v) of acetonitrile. An example of the transition chromatogram is shown in Figure S4. Samples were prepared in quadruplicates.