Lc ms pak filter

Chemical reagents were obtained from Sigma-Aldrich (St. Louis, MO, USA), Steraloids Inc. (Newport, RI, USA), and TRC Chemicals (Toronto, ON, Canada). All standards were accurately weighed and prepared in water, methanol, sodium hydroxide solution, or hydrochloric acid solution to obtain individual stock solutions of 5.0 mg/mL. Appropriate amounts of each stock solution were mixed to create stock calibration solutions. Analytical-grade formic acid (Optima™ LC/MS grade) was obtained from Sigma-Aldrich. Methanol, acetonitrile, and isopropanol of Optima™ LC-MS grade were purchased from Thermo Fisher Scientific (Fair Lawn, NJ, USA). Ultrapure water was produced by a Mill-Q Reference system equipped with an LC-MS Pak filter (Millipore, Billerica, MA, USA). Enzyme-linked immunosorbent assay (ELISA) kits to test for Rotavirus, Coronavirus, and Cryptosporidium antigens in calf feces were obtained from IDEXX (Westbrook, ME, USA).

Formic acid was of analytical grade and obtained from Sigma-Aldrich (St. Louis, MO, USA). Methanol (Optima LC-MS grade), acetonitrile (Optima LC-MS grade), and isopropanol (Optima LC-MS grade) were purchased from Thermo Fisher Scientific (FairLawn, NJ, USA). Sable isotope-labeled internal standards and the derivatization regents, 3-nitrophenylhydrazine (3-NPH) and N-(3-(dimethylamino)propyl)-N′-ethylcarbodiimide (EDC)·HCl were purchased from Sigma-Aldrich (St. Louis, MO, USA). Ultra-pure water was produced by a Milli-Q system equipped with a LC-MS Pak filter (Millipore, Billerica, MA, USA).
All of the standards were purchased from TRC Chemicals (Toronto, ON, Canada), Sigma-Aldrich (St. Louis, MO, USA) and Steraloids Inc. (Newport, RI, USA). They were accurately weighed and dissolved in appropriate solutions to obtain individual stock solutions at the concentration of 5.0 mg mL^− 1. Appropriate amount of each stock solution was mixed to get stock calibration solutions.

All of the standards of the target metabolites were obtained from Sigma–Aldrich (St. Louis, MO, USA), Steraloids Inc. (Newport, RI, USA), and TRC Chemicals (Toronto, ON, Canada). All the standards were accurately weighed and prepared in water, methanol, sodium hydroxide solution, or hydrochloric acid solution to obtain individual stock solutions with a concentration of 5.0 mg/mL. An appropriate amount of each stock solution was mixed to create stock calibration solutions.
Formic acid was of optima grade and obtained from Sigma-Aldrich (St. Louis, MO, USA). Methanol (optima LC–MS), acetonitrile (optima LC–MS), and isopropanol (optima LC–MS) were purchased from Thermo-Fisher Scientific (Fair Lawn, NJ, USA). Ultrapure water was produced by a Mill-Q Reference system equipped with a LC–MS Pak filter (Millipore, Billerica, MA, USA).

Methanol was purchased from Sigma-Aldrich (St. Louis, MO, USA). Methyl chloroformate, acetonitrile, and isopropyl alcohol were obtained from Thermo Fisher Scientific (Fairlawn, NJ, USA). All standard chemicals required for the measurement of other microbial metabolites were obtained from Sigma-Aldrich, Steraloids Inc. (Newport, RI, USA), and TRC Chemical (Toronto, ON, Canada). Ultrapure water was obtained using a Mill-Q Reference system equipped with an LC-MS Pak filter (Millipore, Billerica, MA, USA) (Online Resource 1). In order to analyze changes in the composition of metabolites related to the gut microbiota composition, we conducted ultra-performance liquid chromatography-tandem mass spectrometry analysis to measure the metabolite content.

Methoxyamine HCl, fatty acid methyl ester (C7–C30, FAMEs) standards, pyridine, and anhydrous sodium sulfate were obtained from Sigma-Aldrich (St. Louis, MO, USA). MSTFA (N-methyl-N(trimethylsilyl)trifluoroacetamide) with 1% (vol/vol) trimethylchlorosilane (MSTFA, with 1% TMCS), methanol (Optima LC-MS), acetonitrile (Optima LC-MS), hexane, dichloromethane, chloroform, and acetone were purchased from Thermo-Fisher Scientific (FairLawn, NJ, USA). Ultrapure water was produced by a Mill-Q Reference system equipped with a LC-MS Pak filter (Millipore, Billerica, MA).

Metabolite compound standards were obtained from Sigma-Aldrich (St. Louis, MO, USA), Steraloids Inc. (Newport, RI, USA) and TRC Chemicals (Toronto, ON, Canada). The stock solution for each compound was prepared by dissolving the individual standard in water, methanol, sodium hydroxide, or hydrochloric acid at a concentration of 5.0 mg/mL, and calibration stock solution was made by mixing appropriate amount of each stock solution. Optima LC/MS grade formic acid was obtained from Sigma-Aldrich (St. Louis, MO, USA), and Optima LC/MS grade methanol, acetonitrile, and isopropanol were purchased from Thermo-Fisher Scientific (FairLawn, NJ, USA). Ultrapure water was produced by a Mill-Q Reference system equipped with a LC-MS Pak filter (Millipore, Billerica, MA, USA).