Analytical grade acetonitrile

Anhydrous glucose and rutin were purchased from Sigma-Aldrich (St. Louis, MO, USA). Astragaloside IV was purchased from the National Institutes for Food and Drug Control (Beijing, China). In addition, ferulic acid was purchased from Acros Organics (Geel, Belgium) and ligustilide was purchased from Grand Chemical (Bangkok, Thailand). n-Butylidenephthalide was purchased from Alfa Aesar (Ward Hill, MA, USA). Purified water was prepared while using the Barnstead Easypure II water purification system (Thermo Scientific, Waltham, MA, USA). Analytical-grade acetonitrile was obtained from Honeywell (Morris Plains, NJ, USA), methanol was obtained from Avantor Performance Materials (Center Valley, PA, USA), and acetic acid and phosphoric acid were obtained from Merck (Darmstadt, Germany) (Table 1).

Alpha-cyclodextrin, N,N′-carbonyldiimidazole (CDI), imidazole, and ammonium dihydrogen phosphate were purchased from Sigma Aldrich (St. Louis, MO, USA). Milli Q water was generated using an Ultramatic Wasserlab purification system (Pamplona, Spain). For pH adjustment, 37% hydrochloric acid and 85% ortho-phosphoric acid (Scharlab, Madrid, Spain) were used. Analytical grade acetonitrile was purchased from Honeywell (Charlotte, NC, USA). Bentonites and zeolites were kindly provided by Nurel S.A. (Zaragoza, Spain).

Analytical-grade acetonitrile (ACN), methanol (MeOH), acetone (Ac), and formic acid (FA, HCOOH) were purchased from Honeywell (Morristown, NJ, USA). Nitric Acid (65% v/v) was acquired from Merck KGaA (Darmstadt, Germany). Ultrapure water was produced in the laboratory using a Milli-Q Gradient A10 apparatus (Millipore, Molsheim, France). Salts for extraction based on the AOAC QuEChERS method [33] (link) were purchased from Agilent Technologies (Palo Alto, CA, USA).
All mycotoxin standards were supplied by Trilogy (Washington, USA), except zearalenone, employed as internal standard (IS), that was purchased from Sigma-Aldrich (Augsburg, Germany). Certified standard stock mix solutions of pesticides included in the multi-annual EU plan [15] were purchased from CPA Chem (Stara Zagora, Bulgaria) and individual certified standards of a selection of pesticides outside the programme (purity 95.19–99.9%) were acquired from Dr. Ehrenstorfer (Augsburg, Germany) and Sigma-Aldrich. Pure standards for all elements were purchased in acid solution (5% HNO₃, 100 mg/L, CPA Chem, Stara Zagora, Bulgaria).
Working solutions were prepared for all the standards: a) mycotoxins at 1 µg/mL each in MeOH; b) pesticides, including POPs, at 0.833 µg/mL in ACN and; c) elements at 2 µg/mL each in 2% Nitric Acid.