Paper-Based Ambient Ionization Mass Spectrometry Techniques for Regulatory, Environmental, and Agricultural Challenges Public Deposited

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  • March 19, 2019
  • Reeber, Steven
    • Affiliation: College of Arts and Sciences, Department of Chemistry
  • Sample collection techniques based on the use of a paper substrate have been used in a variety of applications, perhaps most notably in neonatal screening using dried blood spots. These techniques provide a simple and inexpensive way of collecting material for later chemical analysis. The utility of paper-based sample collection is dramatically enhanced by combining it with ambient ionization techniques for mass spectrometry, generating gas phase ions directly from the paper substrate without the sample preparation and separations typically employed. These ions may then be analyzed by a mass spectrometer to detect the compounds of interest. In this work, two ambient ionization methods are explored for the ionization of samples collected on paper substrates. Paper spray ionization is an ambient ionization technique in which a spray of charged droplets is generated from a piece of paper cut to a sharp point. A custom paper spray ion source has been designed and built, and used to explore the potential of paper spray ionization-mass spectrometry for pesticide residue analysis applications. Additionally, the first commercial paper spray ion source has recently been released. An evaluation unit was characterized and compared to the custom paper spray ion source. Using this commercial system, automated methods were developed and used for analysis of pesticides in a variety of matrices, including residual impurity analysis of pesticide formulations. These formulations are highly challenging matrices that typically require sample clean-up and the use of separation techniques; using paper spray ionization a simple dilution in acetonitrile was sufficient to enable analysis. In addition to paper spray ionization, a novel ionization technique was developed to ionize compounds collected on paper matrices. This technique, nib-based electrospray ionization (nibESI) avoids the need to cut the paper to a sharp point by generating the electrospray from a sharpened fountain pen nib. This technique is characterized and applied to the analysis of therapeutic drugs and nicotine in a variety of different matrices including serum and saliva
Date of publication
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Rights statement
  • In Copyright
  • Hicks, Leslie
  • Glish, Gary
  • Dempsey, Jillian
  • Papanikolas, John
  • Jorgenson, James
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2016

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