Browsing by Author "Zhang, Chengsen"

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    Analysis of Biofluids by Paper Spray Mass Spectrometry: Advances and Challenges
    (2016-03) Manicke, Nicholas E.; Bills, Brandon J.; Zhang, Chengsen; Department of Chemistry & Chemical Biology, School of Science
    Abstract Paper spray MS is part of a cohort of ambient ionization or direct analysis methods that seek to analyze complex samples without prior sample preparation. Extraction and electrospray ionization occur directly from the paper substrate upon which a dried matrix spot is stored. Paper spray MS is capable of detecting drugs directly from dried blood, plasma and urine spots at the low ng/ml to pg/ml levels without sample preparation. No front end separation is performed, so MS/MS or high-resolution MS is required. Here, we discuss paper spray methodology, give a comprehensive literature review of the use of paper spray MS for bioanalysis, discuss technological advancements and variations on this technique and discuss some of its limitations.
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    Ionization Suppression and Recovery in Direct Biofluid Analysis using Paper Spray Mass Spectrometry
    (Springer, 2016-04) Vega, Caroline; Spence, Corina; Zhang, Chengsen; Bills, Brandon J.; Manicke, Nicholas E.; Department of Chemistry & Chemical Biology, School of Science
    Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached –90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent.
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    Rapid prototyping using 3D printing in bioanalytical research
    (Future Science, 2017) Zhang, Chengsen; Bills, Brandon; Manicke, Nicholas E.; Chemistry and Chemical Biology, School of Science
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    Targeted Protein Detection using an All-In-One Mass Spectrometry Cartridge
    (ACS, 2017-07) Zhang, Chengsen; Glaros, Trevor; Manicke, Nicholas E.; Chemistry and Chemical Biology, School of Science
    We developed a simple 3D printed cartridge for mass spectrometry (MS) targeted detection of plasma proteins, including post-translational modifications (PTMs). The cartridge uses an integrated antibody enrichment column to preconcentrate the protein target as well as a novel built-in substrate to ionize the protein targets for MS detection. We show several examples of using this cartridge to perform rapid detection of clinically significant proteoforms from plasma samples.