Derivatization of amines for electrochemical detection

Claim 2

A process for the quantitative detection of amines in a fluid sample, comprising: reacting a fluid sample, under a non-reactive atmosphere, with a reactive O-acyl N-hydroxysulfosuccinamide to form an N-acylated derivative of the amine to be detected, wherein said acyl group is selected so as to enhance the separability of said N-acylated amine derivative from polar substances in the remainder of the fluid which may interfere with electrochemical measuring; separating the N-acylated amine derivative from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring; and subjecting the separating N-acylated amine derivative to electrochemical detection coupled to high pressure liquid chromatography.

Claim 3

A process in accordance with claim 1, wherein said fluid sample is a biological fluid.

Claim 4

A process in accordance with claim 1, wherein the acyl group of said reactive O-acyl N-hydroxysulfosuccinamide is selected so as to render said N-acylated amine derivative soluble in an organic solvent, and said separating step comprises extracting the N-acylated amine derivative with a suitable organic solvent.

Claim 5

A process in accordance with claim 1, wherein the acyl group of said reactive O-acyl hydroxysulfosuccinamide is selected so as to render said N-acylated amine derivative isolatable by chromatography from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring, and said separating step is achieved by chromatography.

Claim 6

A process in accordance with claim 1 wherein said reactive O-acyl N-hydroxysulfosuccinamide in water soluble.

Claim 7

In the process for the quantitative detection of electroactive amines in an aqueous fluid sample containing other polar substances, comprising electrochemical detection coupled to high pressure liquid chromatography, the improvement whereby the sensitivity of such process can be substantially increased, comprising the steps of, prior to said detection step: reacting the fluid sample, under a non-reactive atmosphere, with a reactive O-acyl hydroxlamine derivative to form an N-acylated derivative of the electroactive amine to be detected, wherein said reactive O-acyl hydroxylamine derivative is selected to have the property that it is not reactive toward the portion of the electroactive amine to be detected which renders the amine electroactive, and wherein said acyl group is selected so as to render said N-acylated amine derivative soluble in an organic solvent and thereby separable from polar substances in the remainder of the fluid which may interfere with electrochemical measuring; and separating the N-acylated amine derivative from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring by extracting the N-acylated amine derivative with a suitable organic solvent.

Claim 8

In the process for the quantitative detection of electroactive amines in an aqueous fluid sample containing other polar substances, comprising electrochemical detection coupled to high pressure liquid chromatography, the improvement whereby the sensitivity of such process can be substantially increased, comprising the steps of, prior to said detection step: reacting the fluid sample, under a non-reactive atmosphere, with a reactive O-acyl hydroxlamine derivative to form an N-acylated derivative of the electroactive amine to be detected, wherein said reactive O-acyl hydroxylamine derivative is selected to have the property that it is not reactive toward the portion of the electroactive amine to be detected which renders the amine electroactive, and wherein said acyl group is selected so as to render said N-acylated amine derivative soluble in an organic solvent and thereby separable from polar substances in the remainder of the fluid which may interfere with electrochemical measuring; and separating the N-acylated amine derivative from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring by extracting the N-acylated amine derivative with a suitable organic solvent.

Claim 9

A process in accordance with claim 6, further including the step of concentrating the derivative-containing organic solvent solution obtained by said separating step by evaporating a portion of said solvent prior to said detection step.

Claim 10

A process in accordance with claim 6, wherein said O-acyl hydroxylamine derivative is an ester of N-hydroxysuccinamide or an ester of an N-hydroxysulfosuccinamide.

Claim 11

A process in accordance with claim 8, wherein said O-acyl hydroxylamine derivative is a compound of the formula ##STR11## wherein R represents a straight chain alkyl group, a parasubstituted phenol, a hydroquinone, an aniline homolog, an aniline analog, a thiol, an oxidizable thioether, a quinone, a nitroaromatic, a disulfide or --CH 2 NHCONH 2 , and Y is --H or --SO 3 .

Claim 12

A process in accordance with claim 9, wherein R is --CH 3 , --CH 2 CH 3 , --CH 2 NHCONH 2 or ##STR12##

Claim 13

A process in accordance with claim 6, wherein said O-acyl hydroxylamine derivative is an ester of N-hydroxysulfosuccinamide.

Claim 14

A process in accordance with claim 11, wherein said ester of N-hydroxysulfosuccinamide is water soluble.

Claim 15

A process in accordance with claim 6, further including the steps of adding to the fluid sample, prior to said reacting step, a known quantity of an analog or homolog of said electroactive amine having essentially the same reactivity as said amine towards said O-acyl hydroxylamine derivative, thereby serving as an internal standard.

Claim 16

A process in accordance with claim 13, wherein the fluid of said fluid sample is a biological fluid.

Claim 17

A process in accordance with claim 6, wherein the fluid of said fluid sample is a biological fluid.

Claim 18

In the process for the quantitative detection of non-electroactive amines in an aqueous fluid sample containing other polar substances, comprising derivatizing said amines with an electroactive group and detecting said derivatized amine by electrochemical detection coupled to high pressure liquid chromatography, the improvement whereby such non-electroactive amines can be quantitatively detected in the fluid sample at substantial sensitivity, comprising the steps of, prior to said detecting step: reacting the fluid sample, under a non-reactive atmosphere, with a reactive O-acyl hydroxylamine derivative to form an N-acylated derivative of the non-electroactive amine to be detected, wherein said reactive O-acyl hydroxlamine derivative is selected to have the property that it is not reactive toward hydroxyl groups, and wherein said acyl group is selected so as to render said N-acylated amine derivative soluble in an organic solvent and thereby separable from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring and to render said N-acylated amine derivative electroactive; and separating the N-acylated amine derivative from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring by extracting the N-acylated amine derivative with a suitable organic solvent.

Claim 19

In the process for the quantitative detection of non-electroactive amines in an aqueous fluid sample containing other polar substances, comprising derivatizing said amines with an electroactive group and detecting said derivatized amine by electrochemical detection coupled to high pressure liquid chromatography, the improvement whereby such non-electroactive amines can be quantitatively detected in the fluid sample at substantial sensitivity, comprising the steps of, prior to said detecting step: reacting the fluid sample, under a non-reactive atmosphere, with a reactive O-acyl hydroxylamine derivative to form an N-acylated derivative of the non-electroactive amine to be detected, wherein said reactive O-acyl hydroxlamine derivative is selected to have the property that it is not reactive toward hydroxyl groups, and wherein said acyl group is selected so as to render said N-acylated amine derivative soluble in an organic solvent and thereby separable from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring and to render said N-acylated amine derivative electroactive; and separating the N-acylated amine derivative from polar substances in the remainder of the fluid sample which may interfere with electrochemical measuring by extracting the N-acylated amine derivative with a suitable organic solvent.

Claim 20

A process in accordance with claim 16, further including the step of concentrating the derivative-containing organic solvent solution obtained by said separating step by evaporating a portion of said solvent prior to said detection step.

Claim 21

A process in accordance with claim 16, wherein said O-acyl hydroxylamine derivative is an ester of N-hydroxysuccinamide or an ester of an N-hydroxysulfosuccinamide.

Claim 22

A process in accordance with claim 18, wherein said O-acyl hydroxylamine derivative is a compound of the formula ##STR13## wherein R represents a straight chain alkyl group, a parasubstituted phenol, a hydroquinone, an aniline homolog, an aniline analog, a thiol, an oxidizable thioether, a quinone, a nitroaromatic, a disulfide or --CH 2 NHCONH 2 , and Y is --H or --SO 3 .

Claim 23

A process in accordance with claim 19, wherein R is --CH 3 , --CH 2 CH 3 , --CH 2 NHCONH 2 or ##STR14##

Claim 24

A process in accordance with claim 16, wherein said O-acyl hydroxylamine derivative is an ester of N-hydroxysulfosuccinamide.

Claim 25

A process in accordance with claim 21, wherein said ester of N-hydroxysulfosuccinamide is water soluble.

Claim 26

A process in accordance with claim 16, further including the steps of adding to the fluid sample, prior to said reacting step, a known quantity of an analog or homolog of said non-electroactive amine having essentially the same reactivity as said amine towards said O-acyl hydroxylamine derivative, thereby serving as an internal standard.

Claim 27

A process in accordance with claim 23, wherein the fluid of said fluid sample is a biological fluid.

Claim 28

A process in accordance with claim 16, wherein the fluid of said fluid sample is a biological fluid.