6420 triple quad mass spectrometer

The Agilent HPLC–MS/MS system consisted of a 1200 Series liquid chromatography and a 6420 Triple Quad mass spectrometer equipped with an electrospray ionization source (ESI). An Agilent Zorbax SB-Aq C18 column (3.0 × 50 mm, 2.7 μm) was used to separate boscalid and pyraclostrobin and was maintained at 25 °C. The mobile phase was a mixture of 10% aqueous phase (0.2% formic acid in water) and 90% organic phase (pure acetonitrile) flowing at 400 μL/min. The column temperature was 25 °C. The injection volume was 5 μL.
The MS/MS acquisition parameters used for the quantification of the target compounds are provided in Table S1. The desolvation gas temperature was 350 °C, the desolvation gas flow was 10 L/min, and the nebulizer gas (N2) pressure was 45 psi. Analytes were determined in multiple reaction monitoring (MRM) mode.

Total phenolic (TPC) and flavonoid (TFC) contents in the extracts were firstly determined spectrophotometrically as gallic acid and quercetin equivalents, respectively [13 (link)]. Phenolic composition in the extracts was then detected by liquid chromatography–electrospray tandem mass spectrometry (LC–ESI–MS/MS). Analysis was carried out by the Agilent Technologies 1260 Infinity liquid chromatography system hyphenated to a 6420 Triple Quad mass spectrometer. A Poroshell 120 EC-C18 (100 × 4.6 mm I.D., 2.7 µm) column was used. The mobile phases were 0.1%, v/v formic acid solution (Solvent A) and methanol (Solvent B), in gradient elution. Particularly, the gradient elution profile was: 0.00 min 2% B, 3.00 min 2% B, 6.00 min 25% B, 10.00 min 50% B, 14.00 min 95% B, 17.00 min 95% B, and 17.50 min 2% B. The total run time was 18 min. The column temperature was set at 25 °C. The flow rate was 0.4 mL min⁻¹, and the injection volume was 2.0 μL [14 (link),15 (link)]. Furthermore, the tandem MS conditions were an ESI source operated in negative and positive multiple reaction monitoring (MRM) mode, a capillary voltage of −3.5 kV, a gas temperature of 300 °C, a gas flow of 11 L min⁻¹, and a nebulizer pressure of 40 psi. For the quali-quantitative analyses, the single compound was identified by means of retention time, MS, and MS/MS spectra with respect to the standard solution.