Lc ms grade methanol

Ascorbic acid (AA), [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt (ABTS), 2,2′-azobis (2-methylpropionamidine) dihydrochloride (ABAP), 2′,7′-dichlorofluorescein diacetate (DCFH-DA), Folin-Ciocalteau's reagent, Hanks' balanced salt solution (HBSS), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), potassium persulfate, and phenolic standards (apigenin, benzoic acid, caffeic acid, cinnamic acid, p-coumaric acid, ferulic acid, gallic acid, phydroxybenzoic acid, luteolin, mangiferin, protocatechuic acid, syringic acid, vanillic acid, vanillin) were purchased from Sigma-Aldrich (Gillingham, UK). β-Carotene was obtained from Extrasynthese (Genay, France). Acetonitrile, acetone and methanol (LC-MS grade) were purchased from Biosolve B.V. (Valkenswaard, The Netherlands) and acetic and formic acid from VWR International B.V. (Roden, The Netherlands). RPMI, fetal bovine serum (FBS), phosphate buffered saline (PBS), L-glutamine solution (200 mM), trypsin-EDTA solution (170,000 U/l trypsin and 0.2 g/l EDTA) and penicillin-streptomycin solution (10,000 U/mL penicillin and 10 mg/mL streptomycin) were purchased from Lonza (Verviers, Belgium). All other materials and solvents were of analytical grade unless indicated otherwise.

The individual mycotoxin solid calibration standards (1 mg) of AFB1, AFB2, AFG1, AFG2 and zearalanone (ZAN) (internal standard) were obtained from Sigma Aldrich (Bornem, Belgium). All mycotoxin solid standards were dissolved in methanol (1 mg/mL), and were storable for a minimum of 1 year at -18 °C. The working solutions of AFB1, AFB2, AFG1, AFG2 and ZAN (10 ng/µl) were prepared in methanol, stored at -18 °C, and renewed monthly. Water was obtained from a Milli-Q ® SP Reagent water system from Millipore Corp. (Brussels, Belgium). Disinfectol ® (denaturated ethanol with 5 % ether) was supplied by Chem-Lab (Zedelgem, Belgium).
Methanol (LC-MS grade) was purchased from BioSolve (Valkenswaard, the Netherlands), while acetonitrile (Analar Normapur) and ammonium acetate were obtained from VWR International (Zaventem, Belgium). Acetic acid (glacial, 100 %) was supplied by Merck (Darmstadt, Germany). MultiSep ® 228 AflaPat columns were purchased from Romer Labs (Tulln, Austria).
Protease (Aspergillus oryzae, 500 U/g), α-amylase (Aspergillus oryzae, 30 U/mg) and cellulase (Aspergillus niger, 0.3 U/mg) were purchased from Sigma Aldrich (Bornem, Belgium), as TFMSA (≥ 99 %) and KOH (≥ 99 %). sodium acetate buffer (SAB) was prepared with sodium acetate (27.21 g, ≥ 99 % from Sigma Aldrich), glacial Acetic acid (6 mL) and Milli-Q water (994 mL), and the pH was adjusted to 5.0 with NaOH (10 M).

Cortisone and cortisol standards were purchased from Cerilliant (Round Rock, USA), item numbers C-130 and C-106. 13 C 3 -Cortisol and 13 C 3 -Cortisone were obtained from IsoSciences (Ambler, USA), item numbers S14466-0.1 and S14465-0.1. LC-MS grade methanol (catalogue number (CN):13684101), acetonitrile (CN:12401), formic acid (CN:0006914131BS) were purchased from Biosolve (Valkenswaard, The Netherlands). Ammonium fluoride were obtained from Sigma-Aldrich (CN: 338869-25G) (St Louis, USA), ammonium hydroxide from Merck (CN: 5.33003.0050) (Darmstadt, Germany). Ultra-pure water was produced in house by Q-POD Ultrapure Remote Dispenser from Merck Millipore (Burlington, USA).

LC-MS-grade methanol, 2-propanol, water, formic acid and HPLCgrade chloroform was purchased from Biosolve (Valkenswaard, The Netherlands). LC-MS grade ammonium formate and sodium hydroxide were from Sigma-Aldrich Chemie GmbH (St Louis, USA), butanol and hydrochloric acid were from Merck Millipore (Billerica, USA). C18-lysoSM and C18-lysoGb3 were from Avanti (Albaster, USA). 13 C 5 -sphinganine, 13 C 5 -sphingosine, 13 C 5 -GlcSph and 13 C 5 -lysoGb3 were synthesized at the Department of Bio-organic Synthesis of the Leiden Institute of Chemistry, Leiden University [10] . The label was incorporated in C5, 6, 7, 8, and 9 of the sphingosine backbone (see Fig. 1). C18-sphingosine, C18-sphinganine, C18-GlcSph, C18lactosylsphingosine and C17-lysoSM were obtained from Avanti. C17-dihydroceramide (C17-dhCer) was synthesized in house (see Scheme 1); C17-sphinganine, C18-ceramide (Cer), C18glucosylceramide (GlcCer) and Lactosylceramide (LacCer) were purchased from Avanti and C18-globotriaosylceramide (Gb3) from Matreya (State College, USA).

Paracetamol (pharmaceutical secondary standard), Paracetamol sulfate (potassium salt), Paracetamol β-D-glucuronide, formic acid (FA), the internal standard (IS) Paracetamol-D4, calcium chloride, sodium phosphate dibasic (anhydrous), sodium phosphate monobasic (monohydrate) and bovine serum albumin were purchased from Sigma-Aldrich (Diegem, Belgium). LC-MS grade methanol was obtained from Biosolve (Valskenswaard, The Netherlands). Ultrapure water (18.2 MΩ resistivity) was generated in-house by a Synergy® Water Purification System (Merck Millipore, Overijse, Belgium). Potassium chloride and magnesium chloride (hexahydrate) were obtained from Merck (Darmstadt, Germany) and sodium chloride from VWR International (Radnor, PA, USA). Glucose was obtained from Acros Organics (Geel, Belgium). 10 µL VAMS devices (brand name Mitra™) were purchased from Neoteryx (Torrance, CA, USA).