Trinh M Nguyen

US Patent:

7309608, Dec 18, 2007

Filed:

Sep 30, 2003

Appl. No.:

10/675763

Inventors:

Hoa Duc Nguyen - Orange CA, US
Trinh Duc Nguyen - Anaheim CA, US
Duc Tien Nguyen - Westminster CA, US

International Classification:

G01N 33/00

US Classification:

436128, 436 56, 436111, 436173, 436175

Abstract:

A method of identification and quantitative analysis of aldehydes and/or ketones in a sample by mass spectrometry using stable isotope labeled oxime internal standards or stable isotope labeled hydrazone internal standards is provided. Stable isotope labeled oxime internal standards are synthesized by reaction of an authentic sample of aldehydes and/or ketones with a stable isotope labeled alkoxylamine reagent while stable isotope labeled hydrazone internal standards are synthesized by reaction of an authentic sample of aldehydes and/or ketones with a stable isotope labeled alkylhydrazine reagent. A non labeled version of the stable isotope labeled reagent is used to convert aldehydes and/or ketones in the sample to the non labeled version of the stable isotope labeled oxime or hydrazone internal standards.

US Patent:

7439074, Oct 21, 2008

Filed:

Sep 30, 2003

Appl. No.:

10/675765

Inventors:

Hoa Duc Nguyen - Orange CA, US
Trinh Duc Nguyen - Anaheim CA, US
Duc Tien Nguyen - Westminster CA, US

International Classification:

G01N 24/00
G01N 33/14

US Classification:

436173, 436 24

Abstract:

Method of identification and quantitative analysis of alcohol(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said alcohol with a stable isotope labeled reagent, and is added to a sample containing said alcohol. Said alcohol in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said alcohol are made from a plot of ion ratio of said converted alcohol to said internal standard versus alcohol concentration.

US Patent:

7494822, Feb 24, 2009

Filed:

Sep 30, 2003

Appl. No.:

10/675764

Inventors:

Hoa D. Nguyen - Orange CA, US
Trinh D. Nguyen - Anaheim CA, US
Duc T. Nguyen - Westminster CA, US

International Classification:

G01N 24/00
G01N 33/00

US Classification:

436173, 436129

Abstract:

Method of identification and quantitative analysis of carboxylic acid(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said carboxylic acid with a stable isotope labeled reagent, and is added to a sample containing said carboxylic acid. Said carboxylic acid in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said carboxylic acid are made from a plot of ion ratio of said converted carboxylic acid to said internal standard versus carboxylic acid concentration.

US Patent:

20050014279, Jan 20, 2005

Filed:

Jul 14, 2003

Appl. No.:

10/619709

Inventors:

Hoa Nguyen - Orange CA, US
Trinh Nguyen - Anaheim CA, US
Duc Nguyen - Fountain Valley CA, US

International Classification:

A61M036/14
G01N033/00

US Classification:

436106000

Abstract:

Method of identification and quantitative analysis of primary and/or secondary amine(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said amine with a stable isotope labeled reagent, and is added to a sample containing said amine. Said amine in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said amine are made from a plot of ion ratio of said converted amine to said internal standard versus amine concentration.

US Patent:

20050079544, Apr 14, 2005

Filed:

Oct 13, 2003

Appl. No.:

10/684249

Inventors:

Hoa Nguyen - Orange CA, US
Trinh Nguyen - Anaheim CA, US
Duc Nguyen - Westminster CA, US

International Classification:

G01N033/53
G01N033/543

US Classification:

435007100, 436518000

Abstract:

Method of automated metabolic stability analysis of library of compounds by mass spectrometry using stable isotope labeled internal standards is provided. Said internal standards are prepared in situ by reaction of an authentic sample of said library compounds with a stable isotope labeled reagent. In an automated fashion, cytochrome P450 enzyme systems are added to said library compounds; said reactions are terminated after certain periods of time by addition of an organic solvent containing equal amounts of said labeled internal standards; said terminated enzyme reactions are treated with a non-labeled version of said stable isotope labeled reagent to convert remaining library compounds to compounds of identical structures, except the labeled atoms, as those of said labeled internal standards; said conversion reactions are extracted and the extracts are analyzed by isotope dilution mass spectrometry to determine the percentage of library compounds remaining after enzyme reactions.

US Patent:

20070010023, Jan 11, 2007

Filed:

Jul 12, 2006

Appl. No.:

11/486415

Inventors:

Hoa Nguyen - Orange CA, US
Trinh Nguyen - Anaheim CA, US
Duc Nguyen - Fountain Valley CA, US

International Classification:

G01N 33/00

US Classification:

436111000

Abstract:

Method of identification and quantitative analysis of primary and/or secondary amine(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said amine with a stable isotope labeled reagent, and is added to a sample containing said amine. Said amine in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said amine are made from a plot of ion ratio of said converted amine to said internal standard versus amine concentration.

US Patent:

20070010024, Jan 11, 2007

Filed:

Jul 12, 2006

Appl. No.:

11/486416

Inventors:

Hoa Nguyen - Orange CA, US
Trinh Nguyen - Anaheim CA, US
Duc Nguyen - Fountain Valley CA, US

International Classification:

G01N 33/00

US Classification:

436111000

Abstract:

Method of identification and quantitative analysis of primary and/or secondary amine(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said amine with a stable isotope labeled reagent, and is added to a sample containing said amine. Said amine in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said amine are made from a plot of ion ratio of said converted amine to said internal standard versus amine concentration.

US Patent:

20070010025, Jan 11, 2007

Filed:

Jul 12, 2006

Appl. No.:

11/486417

Inventors:

Hoa Nguyen - Orange CA, US
Trinh Nguyen - Anaheim CA, US
Duc Nguyen - Fountain Valley CA, US

International Classification:

G01N 33/00

US Classification:

436111000

Abstract:

Method of identification and quantitative analysis of primary and/or secondary amine(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said amine with a stable isotope labeled reagent, and is added to a sample containing said amine. Said amine in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said amine are made from a plot of ion ratio of said converted amine to said internal standard versus amine concentration.