Methods for detecting vitamin c by mass spectrometry

Abstract

Provided are methods for determining the amount of vitamin C in a sample using mass spectrometry. The methods generally involve ionizing vitamin C in a sample and detecting and quantifying the amount of the ion to determine the amount of vitamin C in the sample.

That which is claimed is: 
     
         1 . A method for determining an amount of ascorbic acid (vitamin C) in a sample, the method comprising:
 (i) extracting vitamin C by high turbulence liquid chromatography;   (ii) ionizing vitamin C in the sample by atmospheric pressure chemical ionization (APCI) in negative ion mode to generate at least one vitamin C ion with a mass/charge ratio of 114.85±0.50 and/or 86.85±0.50 that is detectable by mass spectrometry;   (iii) determining the amount of the at least one said vitamin C ion by tandem mass spectrometry;   wherein the amount of vitamin C in the sample is determined from the amount of vitamin C ion(s) from step (iii).   
     
     
         2 . The method of  claim 1 , wherein the method further comprises high performance liquid chromatography (HPLC). 
     
     
         3 . The method of  claim 1 , wherein the amount of vitamin C in the sample is determined using a calibration standard curve. 
     
     
         4 . The method of  claim 1 , wherein the ions are detected by multiple reaction monitoring (MRM). 
     
     
         5 . A method for determining an amount of ascorbic acid (vitamin C) in a sample, the method comprising:
 (i) purifying vitamin C in the test sample by high turbulence liquid chromatography (HTLC) followed by high performance liquid chromatography (HPLC);   (ii) ionizing vitamin C in the sample by atmospheric pressure chemical ionization (APCI) in negative ion mode to generate at least one vitamin C ion with a mass/charge ratio of 114.85±0.50 and/or 86.85±0.50 that is detectable by mass spectrometry;   (iii) determining the amount of the at least one said C ion by tandem mass spectrometry;   wherein the amount of vitamin C in the sample is determined from the amount of vitamin C ion(s) from step (iii).   
     
     
         6 . The method of  claim 5 , wherein the amount of vitamin C in the sample is determined using a calibration standard curve. 
     
     
         7 . The method of  claim 5 , wherein the ions are detected by multiple reaction monitoring (MRM).