Abstract: A method for screening newborns using electrospray tandem mass spectrometry. The method improves the current protocols that use tandem mass spectrometry by assuring accurate and consistent results at the clinical level through enhanced quality controls and quality assurance protocols as applied to the scan profiling and sample preparation of blood spots from newborns. Specific additives are used in precise concentrations of internal standards, employing detailed controls adapted to distinguish twenty metabolites, which are scanned and vigorously compared to known spectra results. Revealing peaks, metabolite concentration, and scan intensities in the quality assurance steps are then compared to a range of thresholds to determine whether or not the sample is contaminated, drug-ridden, diagnosable, or unacceptable. All spectra results and quality assurance flags are organized in spreadsheet form and exported to a database where values are compiled and stored for daily output results and trend analysis.

Abstract: Measuring thyroxine levels from dried blood samples using mass spectrometry. A test sample is provided that was obtained by treating a dried blood sample with an extraction solution. The test sample also includes an isotopically enriched thyroxine standard. The test sample is scanned using a mass spectrometer to produce one or more mass spectra and the level of thyroxine in the test sample is determined by comparing a peak in the one or more mass spectra that corresponds to thyroxine with a peak in the one or more mass spectra that corresponds to isotopically enriched thyroxine. The level of thyroxine in the dried blood sample is optionally determined based on the extraction efficiency of the extraction solution. Thyroxine levels may be measured in combination with amino acid and/or carnitine levels. Compositions and kits for practicing the method are also provided.

Abstract: A method for screening newborns using electrospray tandem mass spectrometry. The method improves the current protocols that use tandem mass spectrometry by assuring accurate and consistent results at the clinical level through enhanced quality controls and quality assurance protocols as applied to the scan profiling and sample preparation of blood spots from newborns. Specific additives are used in precise concentrations of internal standards, employing detailed controls adapted to distinguish twenty metabolites, which are scanned and vigorously compared to known spectra results. Revealing peaks, metabolite concentration, and scan intensities in the quality assurance steps are then compared to a range of thresholds to determine whether or not the sample is contaminated, drug-ridden, diagnosable, or unacceptable. All spectra results and quality assurance flags are organized in spreadsheet form and exported to a database where values are compiled and stored for daily output results and trend analysis.

Abstract: A method for interpreting data that is produced after a group of amino acids and acylcarnitines are derivatized from blood spots taken from newborn babies and scanned by a tandem mass spectrometer. Concentration levels of each metabolite, which are directly proportional to the butyl ester fragment after derivatization, are compared to threshold flags for determining a significance of any deviation of the metabolite relative to the flag threshold. The threshold flags are diagnostic limits to the data retrieved from each blood spot. The data includes metabolite concentrations and molar ratios of metabolites with other metabolites. Samples are labeled normal for a disease if the concentration of any of the metabolite concentrations or molar ratio concentration do not deviate from the flag threshold, but, in contrast, the sample must be further evaluated if a value is elevated or deficient to some degree.

Abstract: A method for interpreting data that is produced after a group of amino acids and acylcarnitines are derivatized from blood spots taken from newborn babies and scanned by a tandem mass spectrometer. Concentration levels of each metabolite, which are directly proportional to the butyl ester fragment after derivatization, are compared to threshold flags for determining a significance of any deviation of the metabolite relative to the flag threshold. The threshold flags are diagnostic limits to the data retrieved from each blood spot. The data includes metabolite concentrations and molar ratios of metabolites with other metabolites. Samples are labeled normal for a disease if the concentration of any of the metabolite concentrations or molar ratio concentration do not deviate from the flag threshold, but, in contrast, the sample must be further evaluated if a value is elevated or deficient to some degree.

Abstract: A method for interpreting data that is produced after a group of amino acids and acylcarnitines are derivatized from blood spots taken from newborn babies and scanned by a tandem mass spectrometer. Concentration levels of each metabolite, which are directly proportional to the butyl ester fragment after derivatization, are compared to threshold flags for determining a significance of any deviation of the metabolite relative to the flag threshold. The threshold flags are diagnostic limits to the data retrieved from each blood spot. The data includes metabolite concentrations and molar ratios of metabolites with other metabolites. Samples are labeled normal for a disease if the concentration of any of the metabolite concentrations or molar ratio concentration do not deviate from the flag threshold, but, in contrast, the sample must be further evaluated if a value is elevated or deficient to some degree.

Abstract: A method for interpreting data that is produced after a group of amino acids and acylcarnitines are derivatized from blood spots taken from newborn babies and scanned by a tandem mass spectrometer. Concentration levels of each metabolite, which are directly proportional to the butyl ester fragment after derivatization, are compared to threshold flags for determining a significance of any deviation of the metabolite relative to the flag threshold. The threshold flags are diagnostic limits to the data retrieved from each blood spot. The data includes metabolite concentrations and molar ratios of metabolites with other metabolites. Samples are labeled normal for a disease if the concentration of any of the metabolite concentrations or molar ratio concentration do not deviate from the flag threshold, but, in contrast, the sample must be further evaluated if a value is elevated or deficient to some degree.

Abstract: Disclosed herein are methods for diagnosing carnitine deficiency in patients and quantifying that deficiency such that carnitine concentrations can be easily and accurately tracked within a given patient over time. Particular embodiments disclosed herein pertain to methods for diagnosing and quantifying the level of carnitine deficiency in patients undergoing dialysis procedures. The diagnosing and quantifying methods allow high throughput and low cost handling while providing high sensitivity and accuracy analysis such that the methods can be used frequently to monitor patient status, diagnose carnitine deficiency, and manage appropriate therapies to treat carnitine deficiency.

Abstract: Disclosed herein are methods for diagnosing carnitine deficiency in patients and quantifying that deficiency such that carnitine concentrations can be easily and accurately tracked within a given patient over time. Particular embodiments disclosed herein pertain to methods for diagnosing and quantifying the level of carnitine deficiency in patients undergoing dialysis procedures. The diagnosing and quantifying methods allow high throughput and low cost handling while providing high sensitivity and accuracy analysis such that the methods can be used frequently to monitor patient status, diagnose carnitine deficiency, and manage appropriate therapies to treat carnitine deficiency.

Abstract: A method for interpreting data that is produced after a group of amino acids and acylcarnitines are derivatized from blood spots taken from newborn babies and scanned by a tandem mass spectrometer. Concentration levels of each metabolite, which are directly proportional to the butyl ester fragment after derivatization, are compared to threshold flags for determining a significance of any deviation of the metabolite relative to the flag threshold. The threshold flags are diagnostic limits to the data retrieved from each blood spot. The data includes metabolite concentrations and molar ratios of metabolites with other metabolites. Samples are labeled normal for a disease if the concentration of any of the metabolite concentrations or molar ratio concentration do not deviate from the flag threshold, but, in contrast, the sample must be further evaluated if a value is elevated or deficient to some degree.

Abstract: A method for screening newborns using electrospray tandem mass spectrometry. The method improves the current protocols that use tandem mass spectrometry by assuring accurate and consistent results at the clinical level through enhanced quality controls and quality assurance protocols as applied to the scan profiling and sample preparation of blood spots from newborns. Specific additives are used in precise concentrations of internal standards, employing detailed controls adapted to distinguish twenty metabolites, which are scanned and vigorously compared to known spectra results. Revealing peaks, metabolite concentration, and scan intensities in the quality assurance steps are then compared to a range of thresholds to determine whether or not the sample is contaminated, drug-ridden, diagnosable, or unacceptable. All spectra results and quality assurance flags are organized in spreadsheet form and exported to a database where values are compiled and stored for daily output results and trend analysis.