Patent ID: 8569071

Claim:
A method for analyzing one or more amine-containing compounds in one or more samples comprising: providing a standard compound; labeling the standard compound with an isobaric tag from a set of isobaric tags to form an isobarically labeled standard compound; labeling the one or more amine-containing compounds in the one or more samples, each sample with a different respective isobaric tag from the 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 the isobarically labeled standard compound and 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 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; and a second transmitted parent ion m/z range includes an m/z value of the isobarically labeled standard compound and a second transmitted daughter ion m/z range includes an m/z value of a reporter ion corresponding to the isobaric tag of the isobarically labeled standard compound; 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 of the reporter ion corresponding to the isobaric tag of the isobarically labeled standard compound; wherein the one or more amine-containing compounds comprise one or more free amino acids, catecholamines, or nitrofuran metabolites.