Abstract: This disclosure provides methods for quantifying individual amino acids in various bodily fluids obtained from a human patient. Also provided are reference ranges for normal amino acid levels in the various bodily fluids (e.g., blood plasma, urine, cerebrospinal fluid, and saliva) and for various age groups (e.g., neonates, infants, children, and adults).

Abstract: A method for determining an amount of one or more underivatized very long chain fatty acids (VLCFA) selected from the group consisting of docosanoic acid, tetracosanoic acid, and hexacosanoic acid in a sample by mass spectrometry includes (a) subjecting the sample containing an amount of one or more VLCFA to an ionization source to generate one or more underivatized VLCFA ions detectable by mass spectrometry; (b) determining an amount of the one or more underivatized VLCFA ions by mass spectrometry; and (c) determining the amount of the one or more underivatized VLCFA in the sample from the amount of the one or more underivatized VLCFA ions determined in step (b).

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Abstract: A method for determining the amount of testosterone in each of at least two human samples by a single tandem mass spectrometry assay includes subjecting each of a plurality of human samples to a different derivatizing agent to generate a differently derivatized testosterone in each of the plurality of samples, wherein the derivatization agents comprise hydroxylamine chloride and methoxylamine chloride; combining the plurality of samples to form a multiplex sample; and quantifying the amount of testosterone in each sample by mass spectrometry by measuring the amount of a precursor ion having a mass-to-charge ratio of 304.18±0.5 and/or 318.21±0.5 and measuring the amount of a fragment ion having a mass-to-charge ratio of 112.05±0.5, 124.05±0.5, 126.07±0.5, 138.07±0.5, and/or 152.08±0.5.

Abstract: Provided herein are methods for high throughput quantitation of testosterone utilizing at least two different derivatizing agents of different masses. In another aspect, provided herein are methods for determining the amount of testosterone in each of a plurality of human samples with a single mass spectrometric assay by subjecting each of a plurality of human samples to a different derivatizing agent to generate a differently derivatized testosterone in each of the plurality of samples; combining the plurality of samples to form a multiplex sample; and quantifying the amount of testosterone in each sample by mass spectrometry.

Abstract: A method for determining the amount of chromogranin A (CgA) in a sample includes: (a) purifying CgA in the sample; (b) adding an internal standard; (c) ionizing CgA and the internal standard to produce one or more CgA ion(s) and one or more internal standard ion(s) detectable by mass spectrometry; (d) determining the amount of the ion(s) from step (c) by mass spectrometry; and (e) correlating the amount of CgA in the sample to the amount of ion(s) measured in step (d).

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Abstract: Provided herein are methods for high throughput quantitation of testosterone utilizing at least two different derivatizing agents of different masses. In another aspect, provided herein are methods for determining the amount of testosterone in each of a plurality of human samples with a single mass spectrometric assay by subjecting each of a plurality of human samples to a different derivatizing agent to generate a differently derivatized testosterone in each of the plurality of samples; combining the plurality of samples to form a multiplex sample; and quantifying the amount of testosterone in each sample by mass spectrometry.

Abstract: Provided herein are methods for high throughput quantitation of testosterone utilizing at least two different derivatizing agents of different masses. In another aspect, provided herein are methods for determining the amount of testosterone in each of a plurality of human samples with a single mass spectrometric assay by subjecting each of a plurality of human samples to a different derivatizing agent to generate a differently derivatized testosterone in each of the plurality of samples; combining the plurality of samples to form a multiplex sample; and quantifying the amount of testosterone in each sample by mass spectrometry.

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: This disclosure provides methods for quantifying individual amino acids in various bodily fluids obtained from a human patient. Also provided are reference ranges for normal amino acid levels in the various bodily fluids (e.g., blood plasma, urine, cerebrospinal fluid, and saliva) and for various age groups (e.g., neonates, infants, children, and adults).

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Abstract: This disclosure provides methods for quantifying individual amino acids in various bodily fluids obtained from a human patient. Also provided are reference ranges for normal amino acid levels in the various bodily fluids (e.g., blood plasma, urine, cerebrospinal fluid, and saliva) and for various age groups (e.g., neonates, infants, children, and adults).

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: Provided herein are methods for high throughput quantitation of testosterone utilizing at least two different derivatizing agents of different masses. In another aspect, provided herein are methods for determining the amount of testosterone in each of a plurality of human samples with a single mass spectrometric assay by subjecting each of a plurality of human samples to a different derivatizing agent to generate a differently derivatized testosterone in each of the plurality of samples; combining the plurality of samples to form a multiplex sample; and quantifying the amount of testosterone in each sample by mass spectrometry.

Abstract: The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.