Amine-containing compound analysis methods

A method for analyzing one or more amine-containing compounds in one or more samples comprising:

• labeling each of the one or more amine-containing compounds in the one or more samples, each sample with a different respective isobaric tag from a set of isobaric tags, to form one or more samples of one or more isobarically labeled amine-containing compounds;
• combining at least a portion of each sample of the one or more isobarically labeled amine-containing compounds to produce a combined sample;
• loading at least a portion of the combined sample on a chromatographic column;
• eluting components of the combined sample from the chromatographic column;
• subjecting at least a portion of the eluted components to parent-daughter ion transition monitoring, wherein a transmitted parent ion m/z range includes an m/z value of one or more of the isobarically labeled amine containing compounds and a transmitted daughter ion m/z range includes an m/z value of at least one reporter ion corresponding to at least one of the isobaric tags of the one or more isobarically labeled amine containing compounds;
• measuring the ion signal of one or more of the transmitted reporter ions;
• and
• determining the concentration of one or more of the isobarically labeled amine-containing compounds based at least on a comparison of the measured ion signal of at least one reporter ion corresponding to at least one of the isobaric tags of the one or more isobarically labeled amine-containing compounds to a concentration curve of a standard compound;
• wherein the one or more amine-containing compounds comprise one or more free amino acids, catecholamines, or nitrofuran metabolites.

A method for analyzing one or more amine-containing compounds in one or more samples comprising

• labeling the one or more amine-containing compounds in the one or more samples, each sample with a different respective isobaric tag from a set of isobaric tags, to form one or more samples of one or more isobarically labeled amine-containing compounds;
• combining at least a portion of each sample of the one or more isobarically labeled amine-containing compounds to produce a combined sample;
• subjecting at least a portion of the combined sample to parent-daughter ion transition monitoring using matrix assisted laser desorption ionization, wherein a first transmitted parent ion m/z range includes an m/z value of one or more of the isobarically labeled amine containing compounds and a first transmitted daughter ion m/z range includes an m/z value of at least one reporter ion corresponding to at least one of the isobaric tags of the one or more isobarically labeled amine containing compounds;
• measuring the ion signal of one or more of the transmitted reporter ions;
• and
• determining the concentration of one or more of the isobarically labeled amine-containing compounds based at least on a comparison of the measured ion signal of at least one reporter ion corresponding to at least one of the isobaric tags of the one or more isobarically labeled amine-containing compounds to the measured ion signal corresponding to a standard compound;
• wherein the one or more amine-containing compounds comprise one or more free amino acids, catecholamines, or nitrofuran metabolites.