There is need for a method of blood analysis that enables monitoring of critical analytes and provides meaningful and actionable medical assessment. By utilizing dried blood spot (DBS) cards remote and self-testing are enabled. Other attributes are, a smaller amount of blood is required and can be shipped by the patient for analysis, which can occur over international borders. DBS enables analytes in whole blood or serum to be quantified with small amounts of sample in an analytically controlled manner. Sampling of blood for DBS analysis is also simple and can be completed by the patient at home by finger or heel pricks for young children. The current study uses the technique of laser-enhanced ionization coupled to a quadrupole time-of-flight (QTOF) mass spectrometer to analyze the biomedically important peptide, glutathione (GSH). The ratio between GSH and oxidized glutathione (GSSG) is of significant importance in this study, since this ratio is a biomarker for the proper functioning of the immune and detoxification systems in human body. Laser ionization using matrix-assisted laser desorption-ionization (MALDI) can also be applied in the quantification of peptides and other analytes in DBS card analyses. Accurate quantification has not been achieved in laser enhanced ionization previously as it has attempted to use calibration curves which cannot account for the variation in sample arriving at the mass spectrometer. This is being achieved in this research without calibration curves by utilizing speciated isotope dilution mass spectrometry (SIDMS), which eliminates the use of calibration curves and allows the isotopic standards to be the calibration additive with the matrix. This is covered in EPA method 6800 update V, 2013 for Environmental Human Health assessment. The quantification of GSG enables a more robust understanding for physicians to track their patients’ metabolic conditions and eventually will enable improved treatment. The analytical methods will be focused on in this presentation demonstrating these new bioanalytical measurement advances.

Laser-enhanced ionization–mass spectrometry for dried blood spot quantification of a biomedically important analyte

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.