Lcms 8040 tandem mass spectrometer

All chemicals used in the synthesis studies were obtained from Merck Chemicals (Merck KGaA, Darmstadt, Germany) or Sigma-Aldrich Chemicals (Sigma-Aldrich Corp., St. Louis, Mo., USA). The MP90 digital melting point apparatus (Mettler Toledo, OH, USA) was used to determine the melting points (MPs) of the resulting compounds, which were presented uncorrected. Bruker 300-MHz and 75-MHz digital Fourier transform (FT) NMR spectrometers (Bruker Bioscience, Billerica, MA, USA) in dimethyl sulfoxide (DMSO-d₆) were used to record the ¹H NMR and ¹³C NMR spectra, respectively. In the NMR spectra, splitting patterns were determined as follows: s, singlet; d, doublet; t, triplet; dd, double doublet; m, multiplet. Coupling constants (J) are reported in units of Hertz (Hz). An IRAffinity-1S Fourier transform IR (FTIR) spectrometer (Shimadzu, Tokyo, Japan) was used to record the IR spectra of the compounds. Mass spectra were recorded on an LCMS-8040 tandem mass spectrometer (Shimadzu, Kyoto, Japan) by means of electrospray ionization (ESI). Silica gel 60 F254 thin-layer chromatography (TLC; Merck KGaA, Darmstadt, Germany) was used to control the purity of the obtained compounds.

Analysis of amino acids and acylcarnitines in the NS DBS was performed using the flow injection method with an LCMS-8030 tandem mass spectrometer (Shimadzu, Kyoto, Japan). The second-tier measurement of MMA and tHcy in DBS was performed using liquid chromatography–mass spectrometry with an LCMS-8040 tandem mass spectrometer (Shimadzu). Cutoff values for MMA and tHcy were 1 μmol/L and 5 μmol/L, respectively.