Direct Biofluid Analysis Using Hydrophobic Paper Spray Mass Spectrometry

• Published in: Analytical chemistry (Washington) 2016-02, Vol.88 (3), p.1878-1884
• Main Authors: Damon, Deidre E, Davis, Kathryn M, Moreira, Camila R, Capone, Patricia, Cruttenden, Riley, Badu-Tawiah, Abraham K
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Biomarkers; Body Fluids - chemistry; Electrostatics; Humans; Hydrophobic and Hydrophilic Interactions; Liver diseases; Mass spectrometry; Organic chemicals; Point-of-Care Testing; Spectrometry, Mass, Electrospray Ionization - methods; Street Drugs - blood; Street Drugs - urine
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.5b04278

Ambient electrostatic paper spray ionization from a hydrophobic paper occurs when a DC potential is applied to the dry paper triangle. Online liquid/liquid extraction of small organic compounds from a drop of biological fluid present on the dry hydrophobic paper is achieved with an organic spray solvent in under 1 min and utilizes in situ electrostatic-spray ionization for more efficient detection of extracted molecules. Direct analysis of small volumes of biofluids with no sample pretreatment is possible, which is applicable in point-of-care analyses. High sensitivity and quantitative accuracy was achieved for the direct analysis of illicit drugs in 4 μL of raw blood, serum, and whole urine. The study was extended to monitor the activity of alanine transaminase enzyme, a key biomarker for the detection of liver injury in patients (with HIV and tuberculosis) who typically take several medications at once.