Recently there has been increasing interest in using glycerol as a substrate on steam reforming due to the increase of biodiesel production. With the increase of biodiesel production a glut of glycerol has resulted and this would be a more suitable substrate for value added production of hydrogen from reforming. Reforming biorenewable viscous fluids such as glycerol is difficult due to mass transfer limitations associated with vaporizing glycerol to gas phase before steam reforming. This study was to evaluate the feasibility of reforming electrically atomized liquid phase glycerol by means of a technique called electro-spray. It was hypothesized that reforming electrically charged glycerol nanodroplets on an oppositely charged conductive catalyst will increase the reforming performance as opposed to a neutral catalyst-substrate system. Hydrogen yield, selectivity was increased by 20%, 25% respectively when nanodroplets introduced. Exerting an electrical charge to the substrate-catalytic system significantly enhanced the reforming performance irrespective of the physical phase.

The regulations of many food products in the United States have been made and followed very well but unfortunately some products are not put under such rigorous standards as others. This leads to products being sold, that are thought to be healthy, but in reality contain unknown ingredients that may be hazardous to the consumers. With the use of several instrumentations and techniques the detection, characterization and identification of these unknown contaminates can be determined. Both the AZ-100 and the TE2000 inverted microscope were used for visual characterizations, image collection and to help guide the extraction. Direct analyte-probed nanoextraction (DAPNe) technique and nanospray ionization mass spectrometry (NSI-MS) was the technique used for examination and identification of all adulterants. A Raman imaging technique was than introduced and has proven to be a rapid, non-destructive and distinctive way to localize a specific adulterant. By compiling these techniques then applying them to the FDA supplied test samples three major adulterants were detected and identified.

Our group has been studying chiral recognition in gas phase using mass spectrometry for more than 10 years. We are interested in gas phase studies of fundamental interactions because the gas phase avoids complications and masking effects that may arise upon solvation. Therefore, the results of gas phase experiments can be directly compared with those of high-level computational studies. In chapter 2, I studied the roles of hydrogen bonding and pi stacking in gas phase chiral recognition between aromatic crown molecules and aromatic amines. High affinity between host and guest doesn't necessarily result in better recognition. If the affinity is too high, both host enantiomers will bind to the chiral guest very tightly so little discrimination is observed. In order to build an efficient chiral recognition system, we need to select a host and guest that have intermediate binding affinity. Hydrogen bonding is another significant factor that controls the host-guest affinity. In the case of host 1, more hydrogen bonds results in better recognition. We also find that the degree of chiral recognition is greater in the gas phase than in solution. Modeling at the B3LYP/6-31G* level is qualitatively correct, but quantitative agreement with experiment is poor. Inspired by Rekharsky's work which shows successful induced chiral recognition with an achiral host (cucurbituril) in solution, we tested the possibility of applying cucurbiturils as gas phase chiral recognition containers in chapter 5. Conferring chirality on cucurbiturils makes the chiral recognition happen in a restricted space, which might strengthen or hinder the discrimination. By comparing our results with Rekharsky's, we showed the role of solvent in this chiral recognition process. In the gas phase, the enantiodiscrimination does not happen between the "leaving MP" and the "approaching" stronger chiral binder. Because hydrophobic effects are absent in the gas phase, it is possible that the hydrophobic methyl substituent of 2-methylpiperazine and the stronger chiral binder might not be simultaneously included inside the cavity. Therefore, we do not observe enantiodiscrimination in gas phase. The dissociation experiment for the CB[7] ternary complex shows that sec-butylamine binds externally to the CB[7] host. Further, the heterochiral diastereomer is more stable than the homochiral diastereomer. This conclusion is consistent with Rekharsky's result in solution. For more than 15 years, the most common ionization method in our lab has been electrospray ionization. However, ESI is subject to problems with ion suppression, especially when the sample is a mixture or it has a high concentration of salt. The easily ionized molecules tend to scavenge the available charges in the spray solution and dominate the resulting ion population even though other compounds may be present in high abundance. Nanoelectrospray usually yields cold ionization, and analyte suppression can be greatly reduced at nanospray flow rates. Therefore, we constructed a porous polymer monolith (PPM) nanospray emitter similar to that described by Oleschuk et al. and characterized the properties of the PPM emitter. This work is described in chapter 3. Our tests show that this PPM nanospray emitter possesses some special analytical properties: decreased ion suppression, quite stable spray, strong signal intensity and good reproducibility in emitter performance. Chapter 4 deals with the application of the new CRAFTI method to negative ions. CRAFTI stands for cross-sectional areas by Fourier transform ICR. The CRAFTI technique measures collision cross sections, providing a probe of the gas phase conformations of supramolecular complexes. Our preliminary work has shown that CRAFTI is applicable to positive ions, so we further demonstrate the application of the newly-developed method to negative ions in this work. Based on the fact that the experimental cross sections correlate linearly with the theoretical values, we have obtained evidence that CRAFTI is a valid method for negative ions. However, some problems remain. First, we are still working to understand the physical meaning of the CRAFTI cross sections. The absolute values we obtain are generally greater than those obtained from momentum transfer cross section calculations modeled in helium. Second, the precision of the measurements (currently about 2-3%) is still larger than we desire. We need to carefully tune the excitation and isolation amplitudes to make the signal strong and monoisotopic for weak ions. CRAFTI is a very promising and attractive method because FT-ICR provides accurate mass-to-charge measurement along with the cross section measurement. In other words, one technique is sufficient to obtain the shape, size and mass of a molecule simultaneously.

The novel instrumentation of nanomanipulation coupled to nanospray mass spectrometry and its applications are presented. The nanomanipulator has the resolution of 10nm step sizes allowing for specific fine movement used to probe and characterize objects of interest. Nanospray mass spectrometry only needs a minimum sample volume of 300nl and a minimum sample size of 300attograms to analyze an analyte making it the ideal instrument to couple to nanomanipulation. The nanomanipulator is mounted to an inverted microscope and consists of 4 nano-positioners; these nano-positioners hold end-effectors and other tools used for manipulation. This original coupling has been used to enhance the current abilities of cellular probing and trace fiber analysis. Experiments have been performed to demonstrate the functionality of this instrument and its capabilities. Histidine and caffeine have been sampled directly from single fibers and analyzed. Lipid bodies from cotton seeds have been sampled indirectly and analyzed. The few applications demonstrated are only the beginning of nanomanipulation coupled to nanospray mass spectrometry and the possible applications are numerous especially with the ability to design and fabricate new end-effectors with unique abilities. Future study will be done to further the applications in direct cellular probing including toxicology studies and organelle analysis of single cells. Further studies will be directed in forensic applications of this instrument including gunshot residue sampled from fibers.

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applied as to explore limits of detection, sensitivity, and selectivity of analytes as well as immediacy and efficiency of analysis. The application of nanomanipulation-coupled to nanospray ionization-mass spectrometry toward forensic science based applications is considered as future improvements to trace and ultra-trace analysis.

No description available.

<p> Mass spectrometry imaging (MSI) is an advanced analytical technique that renders spatially defined images of complex label-free samples. Nanospray desorption electrospray ionization (nano-DESI) MSI is an ambient ionization direct liquid extraction technique in which analytes are extracted by means of a continuous liquid flow between two fused-silica capillaries. The droplet generated between the two capillaries is controlled by a delicate balance of solvent flow, solvent aspiration, capillary angles, and distance from the surface. This technique produces reproducible ion images with up to 10 µm resolution and can be used to identify and quantify multiple analytes on a given surface.  This thesis discusses some of the applications of this technique to biological systems, as well as the work done to develop methodology to further improve this technique’s specificity and sensitivity. Herein, applications that push the limits of the current capabilities of nano-DESI are presented, such as the high-resolution imaging of lipid species in skeletal muscle at the single-fiber level, and the quantification of low-abundance drug metabolites.  The second theme of this thesis, developing new capabilities, introduces ion mobility mass spectrometry imaging. This integrated technique increases the selectivity previously possible with MSI. To support these efforts, the work in this thesis has generated data analysis workflows that not only make these experiments possible but also further endeavor to increase sensitivity and combat instrument limitations on mobility resolution. Finally, this thesis present streamlined workflows for tandem MS experiments and modifications to a recently introduced microfluidic variant of the nano-DESI technique. In all, this thesis showcases the current capabilities of the nano-DESI technique and lays the groundwork for future improvements and capabilities.      </p>