Abstract: A method for determining a combined amount of ?-tocopherol and ?-tocopherol in a sample by tandem mass spectrometry includes subjecting the sample to ionization under conditions suitable to produce one or more ions from the ?-tocopherol and ?-tocopherol detectable by mass spectrometry; and determining the amount of one or more of the ions by tandem mass spectrometry. Tandem mass spectrometry methods of this disclosure involve fragmenting ?-tocopherol and ?-tocopherol ions having a mass to charge ratio of about 416.35±0.80 into one or more fragment ions including a fragment ion having a mass to charge ratio of about 151.00±0.80, wherein the amount of the one or more ions determined is related to the combined amount of ?-tocopherol and ?-tocopherol in the sample.

Abstract: A method for determining a combined amount of ?-tocopherol and ?-tocopherol in a sample by tandem mass spectrometry includes subjecting the sample to ionization under conditions suitable to produce one or more ions from the ?-tocopherol and ?-tocopherol detectable by mass spectrometry; and determining the amount of one or more of said ions by tandem mass spectrometry, wherein tandem mass spectrometry comprises fragmenting ?-tocopherol and ?-tocopherol ions having a mass to charge ratio of about 416.35±0.80 into one or more fragment ions comprising a fragment ion having a mass to charge ratio of about 151.00±0.80, wherein the amount of the one or more ions determined is related to the combined amount of ?-tocopherol and ?-tocopherol in the sample.

Abstract: A method for determining a combined amount of ?-tocopherol and ?-tocopherol in a sample by tandem mass spectrometry includes subjecting the sample to ionization under conditions suitable to produce one or more ions from the ?-tocopherol and ?-tocopherol detectable by mass spectrometry; and determining the amount of one or more of said ions by tandem mass spectrometry, wherein tandem mass spectrometry comprises fragmenting ?-tocopherol and ?-tocopherol ions having a mass to charge ratio of about 416.35±0.80 into one or more fragment ions comprising a fragment ion having a mass to charge ratio of about 151.00±0.80, wherein the amount of the one or more ions determined is related to the combined amount of ?-tocopherol and ?-tocopherol in the sample.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

Abstract: A method for determining a combined amount of ?-tocopherol and ?-tocopherol in a sample by tandem mass spectrometry includes subjecting the sample to ionization under conditions suitable to produce one or more ions from the ?-tocopherol and ?-tocopherol detectable by mass spectrometry; and determining the amount of one or more of said ions by tandem mass spectrometry, wherein tandem mass spectrometry comprises fragmenting ?-tocopherol and ?-tocopherol ions having a mass to charge ratio of about 416.35±0.80 into one or more fragment ions comprising a fragment ion having a mass to charge ratio of about 151.00±0.80, wherein the amount of the one or more ions determined is related to the combined amount of ?-tocopherol and ?-tocopherol in the sample.

Abstract: Provided are methods of detecting the presence or amount of the active form of vitamin B6, pyridoxal 5?-phosphate, in a body fluid sample using tandem mass spectrometry coupled with liquid chromatography.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

Abstract: Provided are methods for determining the amount of total thiamine in a body fluid sample using liquid chromatography and mass spectrometry. Total thiamine is converted to free thiamine by treatment with an acid phosphatase prior to thiamine separation and quantification.

Abstract: Methods are described for measuring the amount of one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample.

Abstract: Provided are methods of detecting the presence or amount of the active form of vitamin B6, pyridoxal 5?-phosphate, in a body fluid sample using tandem mass spectrometry coupled with liquid chromatography.

Abstract: Provided are methods for determining the amount of total thiamine in a body fluid sample using liquid chromatography and mass spectrometry. Total thiamine is converted to free thiamine by treatment with an acid phosphatase prior to thiamine separation and quantification.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

Abstract: Provided are methods of detecting the presence or amount of the active form of vitamin B6, pyridoxal 5?-phosphate, in a body fluid sample using tandem mass spectrometry coupled with liquid chromatography.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

Abstract: Provided are methods of detecting the presence or amount of the active form of vitamin B6, pyridoxal 5?-phosphate, in a body fluid sample using tandem mass spectrometry coupled with liquid chromatography.

Abstract: Methods are described for measuring the amount of one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample.

Abstract: Methods are described for measuring the amount of one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying one or more of vitamin A, ?-tocopherol, and the combination of ?-tocopherol and ?-tocopherol in a sample.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

Abstract: Methods are described for measuring the amount of a vitamin B2 in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying vitamin B2 in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.

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.