Biogenic amine assay using HPLC-ECD
First Claim
1. A method for the assaying of low concentrations of an oxidizable or reducible biogenic amine or derivative or metabolite thereof, comprising the steps of:
- (a) preparing a sample of at least one said compound, said sample being suitable for quantitative analysis;
(b) injecting said sample into a high pressure liquid chromatography apparatus to thereby form a chromatogram, said apparatus including;
(1) a chromatography column containing a quantity of microparticulate material as a stationary phase;
(2) a mobile phase passing through said stationary phase, said mobile phase comprising the following components;
(a) from about 50 mM to about 250 mM of a buffer having a pH of from about 2 to about 8;
(b) from about 0.1 mM to about 10.0 mM of a chelating agent;
(c) from about 0.1 mM to about 10.0 mM of an alkyl sulfonate, said alkyl sulfonate having from about 4 to about 14 carbon atoms; and
(d) from about 0.1% to about 10% by volume methanol in water solution;
(3) an injector for injecting said sample;
(4) a pump for pumping said mobile phase through said stationary phase; and
(5) a guard column positioned upstream of said chromatography column;
(c) eluting said compounds from said chromatography column;
(d) passing said eluted compounds through an electrochemical detector cell thereby producing a current output from said detector;
(e) measuring and integrating the current output from said electrochemical detector to obtain a quantitative analysis of said compound; and
(f) maintaining a substantially constant base line noise at a sensitivity of said electrochemical detector cell sufficient to measure the quantity of said compound present in resting, human plasma by maintaining all portions of said apparatus contacting said mobile phase and said stationary phase substantially residue-free, wherein the signal to noise ratio of said current output is at least 2 to 1.
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Abstract
A method for assaying compounds belonging to the group biogenic amines and including catecholamines, indoleamines, their metabolites and derivatives, and other small molecular weight compounds using a boric acid extraction method followed by high pressure liquid chromatographic separation in conjunction with electrochemical detection. The method utilizes high purity chemical and liquid components, a microparticulate-silica bonded phenyl stationary phase in the chromatography column and special cleaning and maintenance measures for the various components of the assaying apparatus which result in reduced baseline noise and allow the electrochemical cell to be operated at a sensitivity of one nanoamp or less full scale deflection on a continuous basis.
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Citations
60 Claims
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1. A method for the assaying of low concentrations of an oxidizable or reducible biogenic amine or derivative or metabolite thereof, comprising the steps of:
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(a) preparing a sample of at least one said compound, said sample being suitable for quantitative analysis; (b) injecting said sample into a high pressure liquid chromatography apparatus to thereby form a chromatogram, said apparatus including; (1) a chromatography column containing a quantity of microparticulate material as a stationary phase; (2) a mobile phase passing through said stationary phase, said mobile phase comprising the following components; (a) from about 50 mM to about 250 mM of a buffer having a pH of from about 2 to about 8; (b) from about 0.1 mM to about 10.0 mM of a chelating agent; (c) from about 0.1 mM to about 10.0 mM of an alkyl sulfonate, said alkyl sulfonate having from about 4 to about 14 carbon atoms; and (d) from about 0.1% to about 10% by volume methanol in water solution; (3) an injector for injecting said sample; (4) a pump for pumping said mobile phase through said stationary phase; and (5) a guard column positioned upstream of said chromatography column; (c) eluting said compounds from said chromatography column; (d) passing said eluted compounds through an electrochemical detector cell thereby producing a current output from said detector; (e) measuring and integrating the current output from said electrochemical detector to obtain a quantitative analysis of said compound; and (f) maintaining a substantially constant base line noise at a sensitivity of said electrochemical detector cell sufficient to measure the quantity of said compound present in resting, human plasma by maintaining all portions of said apparatus contacting said mobile phase and said stationary phase substantially residue-free, wherein the signal to noise ratio of said current output is at least 2 to 1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 59)
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57. A method for the assaying of low concentrations of an oxidizable or reducible compound comprising the steps of:
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(a) preparing a sample of at least one of said compounds, said sample being suitable for quantitative analysis; (b) injecting said sample into a high pressure liquid chromatography apparatus to thereby form a chromatogram, said apparatus including; (1) a chromatography column containing a quantity of microparticulate material as a stationary phase; (2) a mobile phase passing through said stationary phase, said mobile phase comprising the following components; (a) from about 50 mM to about 250 mM of a buffer having a pH of from about 2 to about 8; (b) from about 0.1 mM to about 10.0 mM of a chelating agent; (c) from about 0.1 mM to about 10.0 mM of an alkyl sulfonate, said alkyl sulfonate having from about 4 to about 14 carbon atoms; and (d) from about 0.1% to about 10% methanol in water solution; (3) an injector for injecting said sample; (4) a pump for pumping said mobile phase through said stationary phase; and (5) a guard column positioned upstream of said chromatography column; (c) eluting said compounds from said chromatography column; (d) passing said eluted compounds through an electrochemical detector cell thereby producing a current output from said detector; (e) measuring and integrating the current output from said electrochemical detector to obtain a quantitative analysis of said compound; and (f) maintaining a sensitivity of said electrochemical detector cell at about 1 nanoamp or less full scale deflection by maintaining all portions of said apparatus contacting said mobile phase and said stationary phase substantially residue-free, wherein the signal to noise ratio of said current output is at least about 2 to 1. - View Dependent Claims (58, 60)
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Specification