Amine-containing compound analysis methods

Abstract

The present teachings provide methods for analyzing one or more amine-containing compounds in one or more samples using isobaric labels and parent-daughter ion transition monitoring (PDITM). In various embodiments, the methods comprise the steps of: (a) labeling one or more amine-containing compounds with different isobaric tags from a set of isobaric tags, each isobaric tag comprising a reporter ion portion; (b) combining at least a portion of each of the isobarically labeled amine-containing compounds to produce a combined sample; (c) subjecting at least a portion of the combined sample to PDITM; (d) measuring the ion signal of one or more of the transmitted reporter ions; and (e) 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 the corresponding reporter ion to one or more measured ion signals of a standard compound.

1 . A method for analyzing one or more of amine-containing compounds in one or more samples comprising the steps of: 
 providing a standard compound;    labeling the standard compound with an isobaric tag from a set of isobaric tags;    labeling one or more amine-containing compounds each with a different isobaric tag from the set of isobaric tags;    combining at least a portion of the isobarically labeled standard compound with at least a portion of each of the isobarically labeled amine-containing compounds to produce a combined sample;    loading at least a portion of the combined sample on a chromatographic column;    subjecting at least a portion of the eluent from the chromatographic column to parent-daughter ion transition monitoring wherein, 
 a first transmitted parent ion m/z range includes a m/z value of one or more of the isobarically labeled amine containing compounds and a first transmitted daughter ion m/z range includes a m/z value of at least one reporter ion corresponding to at least one of the isobaric tags of the isobarically labeled amine containing compounds; and  
 a second transmitted parent ion m/z range includes a m/z value of one or isobarically standard compound and a second transmitted daughter ion m/z range includes a 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 the corresponding reporter ion to the measured ion signal of a reporter ion corresponding to the isobarically labeled standard compound.    
     
     
         2 . The method of  claim 1 , wherein one or more of the samples comprise a physiological fluid.  
     
     
         3 . The method of  claim 1 , wherein one or more of the samples comprise one or more of a agricultural product, animal product, animal feed, a food for human consumption, and a beverage for human consumption.  
     
     
         4 . The method of  claim 1 , wherein the one or more amine-containing compounds comprise substantially the same amine-containing compound from two or more samples.  
     
     
         5 . The method of  claim 1 , wherein the one or more amine-containing compounds comprise one or more amino acids.  
     
     
         6 . The method of  claim 5 , wherein the one or more amine-containing compounds comprise one or more isomers of the same amino acid.  
     
     
         7 . The method of  claim 5 , wherein the one or more amine-containing compounds comprise one or more post translational modifications of the same amino acid.  
     
     
         8 . The method of  claim 1 , wherein the one or more amine-containing compounds comprise one or more amine-containing compounds contained in a protein or polypeptide.  
     
     
         9 . The method of  claim 8 , wherein the protein or polypeptide comprises one or more cytochrome P450 isoforms.  
     
     
         10 . The method of  claim 1 , wherein the one or more amine-containing compounds comprise one or more catecholamines or nitrofuran metabolites.  
     
     
         11 . The method of  claim 10 , wherein the catecholamines comprise one or more of epinephrine, norepinephrine, and L-dopa.  
     
     
         12 . The method of  claim 10 , wherein the nitrofuran metabolites comprise one or more of 3-amino-2-oxazolidinone, 5-morpholinomethyl-3-amino-oxazolidinone, semicarbazide, and 1-aminohydantoin.  
     
     
         13 . The method of  claim 1 , wherein the step of subjecting at least a portion of the eluent from the chromatographic column to parent-daughter ion transition monitoring comprises using one or more of a triple quadrupole, quadrupole/time-of-flight mass spectrometer, linear ion trap mass spectrometer, or a tandem time-of-flight mass spectrometer.  
     
     
         14 . The method of  claim 1 , wherein the step of subjecting at least a portion of the eluent from the chromatographic column to parent-daughter ion transition monitoring comprises mixing the combined sample in a matrix and using matrix assisted laser desorption ionization to produce ions for the parent-daughter ion transition monitoring.  
     
     
         15 . The method of  claim 14 , wherein the one or more amine-containing compounds comprises one or more of lysine, an isomer of lysine, and a post translationally modified lysine, and the matrix comprises a cyano-4-hydroxy cinnamic acid (CHCA).  
     
     
         16 . The method of  claim 14 , wherein the one or more amine-containing compounds comprises one or more of argininee, an isomer of arginine, and a post translationally modified arginine, and the matrix comprises a dihydroxybenzoic acid (DHB).  
     
     
         17 . The method of  claim 1 , wherein the step of determining the concentration of one or more of the isobarically labeled amine-containing compounds comprises determining the absolute concentration of one or more of the isobarically labeled amine-containing compounds.  
     
     
         18 . A method for analyzing one or more of amine-containing compounds in one or more samples comprising the steps of: 
 labeling one or more amine-containing compounds each with a different isobaric tag from a set of isobaric tags;    combining at least a portion of each of the isobarically labeled amine-containing compounds to produce a combined sample;    loading at least a portion of the combined sample on a chromatographic column;    subjecting at least a portion of the eluent from the chromatographic column to parent-daughter ion transition monitoring wherein, the transmitted parent ion m/z range includes a m/z value of one or more of the isobarically labeled amine containing compounds and the transmitted daughter ion m/z range includes a m/z value of at least one reporter ion corresponding to at least one of the isobaric tags of the isobarically labeled amine containing compounds; and    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 the corresponding reporter ion to a concentration curve of a standard compound.    
     
     
         19 . The method of  claim 18 , where the concentration curve of the standard compound is generated by: 
 (a) providing a standard compound having a first concentration;    (b) labeling the standard compound with an isobaric tag from a set of isobaric tags;    (c) loading at least a portion of the isobarically labeled standard compound on a chromatographic column;    (d) subjecting at least a portion of the eluent from the chromatographic column to parent-daughter ion transition monitoring wherein, the transmitted parent ion m/z range includes a m/z value of the isobarically labeled standard compound and the transmitted daughter ion m/z range includes a m/z value of a reporter ion corresponding to the isobaric tag of the isobarically labeled standard compound;    (e) measuring the ion signal of the transmitted reporter ions;    (f) repeating steps (a)-(e) for one or more different standard compound concentrations; and    (g) generating a concentration curve for the standard compound based at least on the measured ion signal of the transmitted reporter ions at two or more standard compound concentrations.    
     
     
         20 . The method of  claim 18 , wherein the step of determining the concentration of one or more of the isobarically labeled amine-containing compounds comprises determining the absolute concentration of one or more of the isobarically labeled amine-containing compounds.  
     
     
         21 . A method for analyzing one or more of amine-containing compounds in one or more samples comprising the steps of: 
 labeling one or more amine-containing compounds each with a different isobaric tag from a set of isobaric tags;    combining at least a portion of each of the 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 a m/z value of one or more of the isobarically labeled amine containing compounds and a first transmitted daughter ion m/z range includes a m/z value of at least one reporter ion corresponding to at least one of the isobaric tags of the 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 the corresponding reporter ion to the measured ion signal of a standard compound.    
     
     
         22 . The method of  claim 21 , wherein the one or more amine-containing compounds comprises one or more of lysine, an isomer of lysine, and a post translationally modified lysine, and the matrix comprises a cyano-4-hydroxy cinnamic acid (CHCA).  
     
     
         23 . The method of  claim 21 , wherein the one or more amine-containing compounds comprises one or more of argininee, an isomer of arginine, and a post translationally modified arginine, and the matrix comprises a dihydroxybenzoic acid (DHB).  
     
     
         24 . The method of  claim 21 , wherein the step of determining the concentration of one or more of the isobarically labeled amine-containing compounds comprises determining the absolute concentration of one or more of the isobarically labeled amine-containing compounds.