Acquity ultra performance lctm system

An ACQUITY Ultra Performance LC^TM system (Waters, Milford, MA, USA) linked to a PDA 2996 photodiode array detector (Waters) was used for ultra-high-performance liquid chromatography (UPLC) analysis, following the method of Pane et al. [27 (link)]. The acquisition and processing of the relative data, as well as the control of the instruments was performed through the Empower software. The extracts and standards (which were previously dissolved in methanol to have different concentrations ranging from 0.001 to 5 mM) were filtered (0.45 μm; Waters, Milford, MA, USA) before analysis. The analyses were carried at 30 °C using a reversed phase column (BEH C₁₈, 1.7 μm, 2.1 × 100 mm; Waters). The mobile phase consisted of solvent A (7.5 mM acetic acid) and solvent B (acetonitrile) at a flow rate of 250 μL min^‒1. A gradient elution was employed, starting with 5% B for 0.8 min, then 5–20% B over 5.2 min, isocratic 20% B for 0.5 min, 2%30% B for 1 min, isocratic 30% B for 0.2 min, 30–50% B over 2.3 min, 50–100% B over 1 min, and isocratic 100% B for 1 min, 5–100% B over 0.5 min, and finally the column was equilibrated under the initial conditions for 2.5 min. The pressure ranged from 6000 to 8000 psi. The injection volume was 5 μL. The effluent was introduced into an LC detector (scanning range: 210–400 nm, resolution: 1.2 nm).

Polyphenol profile of the different cultivars of apricot was evaluated by ultra-high-performance liquid chromatography (UPLC) analysis using the ACQUITY Ultra Performance LC^TM system (Waters, Milford, MA, USA) connected to a PDA 2996 photodiode array detector (Waters). The connected Empower software (Waters) allowed the control of the instruments and the acquisition and processing of the relative data. The analysis was performed following the methods described by Pane et al. [21 (link)]. Extracts and standards were dispersed in methanol; then they were filtered using microfilter units Whatman 0.45 μm (Waters, Milford, MA, USA). Running conditions = Injection volume: 5 μL. Mobile phase: solvent A (7.5 mMol acetic acid) and solvent B (acetonitrile); flow rate: 250 μL min⁻¹; column: reversed-phase column (BEH C18, 1.7 μm, 2.1 × 100 mm Waters); temperature: 30 °C. Each analysis was performed with a gradient elution (0.8 min: 5% B for; 5.2 min: from 5% to 20% B; 0.5 min: 20% B; 1 min: from 20 to 30% B; 0.2 min: 30% B; 2.3 min: from 30% to 50% B; 1 min: from 50% to 100% B; 1 min:100% B; 0.5 min to reach 5% B from 100% B. Then, the column was restored to the initial conditions for 2.5 min. Quantification of polyphenols were made based on linear curves of the standards.