Lc ms grade methanol and water

Scotch Whisky samples were provided by the Scotch Whisky Research Institute (SWRI). A total of 85 authentic Scotch Whisky samples were analyzed, consisting of a mixture of malts and blends. The main sample set was the SWRI standard sample set from 2014 (n_malts = 24, n_blends = 28). Further samples were sourced from subsets of previous years’ standard sample sets (i.e., 2010 (n_malts = 23, n_blends = 1) and 2012 (n_malts = 8, n_blends = 1). The sample sets were curated by the SWRI to represent the majority of Scotch Whisky sold as UK or export case sales; 2014 (73.15% of total sales), 2012 (71.2% of total sales), and 2010 (67.4% of total sales) [51 , 54 , 55 ]. In this work, malts refer to both single malt and blended malts, whilst blends refer to blended whisky. There are no single or blended grain whiskies in the sample set, as these represent a very small percentage of products on the market. A malt new-make spirit sample was also analyzed. Samples are referred to by an anonymized reference label of the format SYY-XXXX, where YY refers to the sample set year and XXXX is a unique identifier for the sample in that year. LC-MS grade methanol and water were purchased from Sigma Aldrich, Dorset, UK. Samples (30 μL) were diluted 1:10 in methanol:water (50:50) immediately prior to direct infusion into the ESI source. The dilution ratio was optimized to minimize potential carryover effects.

Formic acid, acetic acid, LC-MS grade methanol and water, and HPLC grade acetone and buffer solutions were obtained from Sigma Chemical Co. (St. Louis, MO, USA).

Folin–Ciocalteu reagent, DPPH, ABTS, TPTZ, potassium persulfate, gallic acid, Trolox and the other standards were purchased from Sigma-Aldrich (St. Louis, MO, USA). LC-MS grade methanol and water, glacial acetic acid, iron chloride hexahydrate, sodium carbonate and ethanol for the extraction were purchased from Merck KGaA (Darmstadt, Germany). Vanillic acid (≥97%), rutin (≥95%), catechin (≥99%), chlorogenic acid (≥95%), ferulic acid (≥99 %), cyanidin-3-O-glucoside (Cy-3-glu) (≥98%), ascorbic acid (>99%), quercetin (≥95%) and geraniol (≥98.5%) standards were also purchased from Sigma-Aldrich (St. Louis, MO, USA).

Folin–Ciocalteu (F-C) reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,4,6-tri (2-pyridyl)-1,3,5-triazine (TPTZ), gallic acid and Trolox were purchased from Sigma-Aldrich (St. Louis, MO, USA). Ethanol, water and methanol HPLC grade, glacial acetic acid, iron chloride hexahydrate and sodium carbonate were purchased from VWR (Radnor, PA, USA). Vanillic acid, quercetin, rutin, chlorogenic acid, ferulic acid and catechin standards were also purchased from Sigma-Aldrich (St. Louis, MO, USA). LC-MS grade methanol and water, acetonitrile, sorbic acid (E-200), 5-fluorouracil and sodium acetate were purchased from Merck KgaA (Darmstadt, Germany).
Vaccinium myrtillus dry leaves were purchased from Bidah Chaumel (Murcia, Spain). They proceed from an organic field located in Huelva (Spain), and were collected in June 2022. Fresh leaves were air dried in dark conditions at room temperature in order to reach a moisture of 10.5%. They were grounded to an average particle size of 0.8 mm and stored at −20 °C until the extraction.