title: The use of multiple mass spectral line pairs for enhanced precision in isotope enrichment studies of 15N-labeled amino acids.
abstract: A method for enhancing the precision in the calculation of isotope enrichment for 15N-labeled amino acids is presented. The method utilizes multiple line pairs for the calculation of isotope enrichment. Using multiple line pairs allows the evaluation of calibration curves for nonlinear behavior and permits differentiation among sites containing more than one labeled nitrogen. The increase in precision is related to the number of isotopically shifted line pairs used in calculating the isotopic enrichment and varies with the amino acid of interest.
authors.affiliation: Department of Chemistry, University of Akron, Ohio 44325.
authors.forename: T A
authors.initials: TA
authors.lastname: Lee
authors.forename: T M
authors.initials: TM
authors.lastname: Forrest
authors.forename: G E
authors.initials: GE
authors.lastname: Wilson
authors.forename: J K
authors.initials: JK
authors.lastname: Hardy
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D001412:Bacillus subtilis / Q000032:analysis; D003960:Diaminopimelic Acid; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009587:Nitrogen Isotopes; D015203:Reproducibility of Results
chemical_list: D000596:Amino Acids; D009587:Nitrogen Isotopes; D003960:Diaminopimelic Acid