Milli q water advantage a 10 water system

The following compounds were obtained commercially from the sources given in parentheses: formic acid, sodium hydroxide (Merck, Darmstadt, Germany), histamine, ethanolamine, 2-phenylethylamine, putrescine, β-alanine, tyramine, spermine, spermidine, trichloroacetic acid (Sigma-Aldrich, Taufkirchen, Germany), benzoyl chloride (VWR, Darmstadt, Germany), [2H4]-histamine, [2H4]-putrescine (CDN Isotopes, Quebec, Canada), [13C2]-ethanolamine, [13C3,15N]-β-alanine (Sigma-Aldrich, St. Louis, MO, USA), [2H4]-phenylethylamine (Dr. Ehrenstorfer, Augsburg, Germany). The purity of all amines was checked by LC-MS and NMR experiments as described by Mayr and Schieberle, 2012 (link). Deuterated solvents were obtained from Euriso-Top (Gif-Sur-Yvette, France). Solvents used for HPLC-MS/MS analysis were of LC-MS grade (Honeywell, Seelze, Germany); all other solvents were of HPLC grade (Merck Darmstadt, Germany). Water used for HPLC separation was purified by means of a Milli-Q water advantage A 10 water system (Millipore, Molsheim, France). [2H4]-spermine, [2H2]-tyramine and [2H4]-spermidine were synthesized and purified as reported earlier (Mayr and Schieberle, 2012 (link)). Standard flyfood consisted of the following ingredients: agar, corn flour, soy flour, yeast, malt, molasses, nipagin, ethanol, phosphoric acid.

The following compounds were obtained commercially: formic acid, ethanol (Merck, Darmstadt, Germany); solvents were of HPLC grade (Merck Darmstadt, Germany). Water used for chromatography was purified by means of a Milli-Q water advantage A 10 water system (Millipore, Molsheim, France). The black peppercorn samples were purchased from the German retail market. The Capsaicin, Capsazepine, ethylene glycol tetraacetic acid (EGTA), dimethyl sulfoxide (DMSO), HC-030031, and piperine were purchased from Sigma–Aldrich (Steinheim, Germany). The stock solutions of 100 mM were diluted in DMSO and were made for all the employed sensory active chemical compounds. These were stored at –20°C. The aliquots were then diluted to obtain the desired concentrations.

The following compounds were obtained commercially from the sources given in parentheses: formic acid, chloroform (HPLC grade) (Merck, Darmstadt, Germany); acetonitrile (MS grade, J. T. Baker, Deventer, Netherlands); (CD₃)₂CO was obtained from Euriso-Top (Gif-Sur-Yvette, France). Water for UHPLC separation was purified by means of a Milli-Q water advantage A 10 water system (Millipore, Molsheim, France).