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ABSTRACT In this paper we describe the use of electrospray-assisted pyrolysis ionization/mass spectrometry (ESA-Py/MS) to selectively ionize trace polar compounds that coexist with large amounts of nonpolar hydrocarbons in synthetic polymer, crude oil, amber, humic substances, and rubber. Samples of different origins are distinguished rapidly by their ESA-Py mass spectra without prior separation or chemical pretreatment. During ESA-Py analysis, the samples in their solid or liquid states were pyrolyzed at 590 ¢XC using a commercial Curie-point pyrolytical probe; the gaseous pyrolysates were transferred into a glass reaction cell; the polar compounds (M) in the pyrolysates were then ionized in the form of protonated molecules (MH+), through their reactions with the charged species in the ESI plum. Although the major components of the pyrolysates are nonpolar hydrocarbons, their lack of functional groups that can receive a proton in the ESA-Py source results in no hydrocarbon ion signals being produced; thus, the ions detected in ESA-Py mass spectra all result from trace polar component in the pyrolysates.

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Um Proteine und Peptide ohne Verluste in der Trennleistung mit Hilfe der Kapillarelektrophorese zu analysieren, wurde der Innenkanal von fused silica Kapillaren mit 2-Hydroxyethylmethacrylat (HEMA) nach dem Prinzip der radikalischen Atomtransferpolymerisation beschichtet. Durch die Variation einiger Reaktionsparameter konnten dabei vier HEMA-Beschichtungen erhalten werden. Mit diesen wurden dann nach den Methoden der Kapillarzonenelektrophorese bei pH 3 und pH 9 und der isoelektrischen Fokussierung Vergleichsmessungen durchgeführt. Die Detektion erfolgte dabei teilweise mit einem Elektrosprayionisations-Flugzeit-Massenspektrometer. Es stellte sich heraus, dass sich die entwickelten Kapillarbeschichtungen im Bezug auf Trenneffizienz wie auch Stabilität im basischen Bereich teilweise stark voneinander unterschieden. Die Betrachtung der Polymerschichten mit Hilfe der Atomkraftmikroskopie zeigte, dass die Morphologie der HEMA-Beschichtung stark vom gewählten Reaktionsmedium abhängig ist.

In der vorliegenden Arbeit wird die Synthese von Carbosiloxandendrimeren der dritten Generation durch repetitive Alkoholyse-Hydrosilylierungs-cyclen auf dem divergenten Syntheseweg beschrieben. Im Mittelpunkt der Arbeit stand jedoch die Funktionalisierung dieser Dendrimere mit einer Vielzahl metallorganischer (Ferrocenyl-, Übergangsmetallcarbonyl-verbindungen) bzw. organischer (stickstoffhaltige Ligandsysteme) Einheiten. Zudem wird die Darstellung amphiphiler und bifunktionaler Carbosiloxandendrimere vorgestellt. Die neu synthetisierten Verbindungen wurden analytisch umfassend charakterisiert, wobei die 29Si-{1H}-NMR-Spektroskopie sowie die Massenspektrometrie einen besonderen Stellenwert einnehmen.

Reading to learn becomes a difficult task for children if they have not become proficient at comprehending written text. It was hypothesized that, for some children, reading difficulties may have been averted had they been reared in homes or participated in early childhood settings where literacy-based activities, interactions, or materials were prevalent. The purpose of this study was to examine the impact that training early childhood educators in research based early literacy instructional strategies (within the HeadsUp! Reading curriculum HUR) had on the development of early reading skills in the preschool children they taught. Further examination also identified the impact that providing teachers with a Literacy Coach (LC) to mentor them in their application of the strategies had on early literacy development. The HUR class, LC positions, and additional resources provided to teachers partaking in this early childhood educator training were funded by the Early Learning Opportunities (ELO) grant. To examine the impact that teacher participation in the ELO grant had on childrens early literacy development, a hierarchical linear modeling (HLM) was conducted with childrens early literacy development measured at two points in time by the Individual Development and Growth Indicators (IGDI). After examining these indicators within a three-level model, change over time was documented. Specifically, age and race emerged as significant predictors of rates of literacy skill acquisition with older students and White students demonstrating higher rates of literacy development. Household socioeconomic status (SES) of children also accounted for significant amounts of variance in literacy development with higher rates of growth found in children from higher household SES.

This dissertation includes molecular and phytochemical investigations of the harmful, bloom-forming alga, Prymnesium parvum, including analysis of known polyketide metabolites as a function of salinity and growth. Initially, the development of molecular and phytochemical tools was necessary for the detection and quantification of P. parvum and its associated toxins. Suites of oligonucleotides and molecular beacons were designed for conventional and quantitative multiplex PCR to amplify four species- and gene-specific products simultaneously that were used for the detection and quantitation of P. parvum. This built-in redundancy provided increased confidence in reactions with the positive confirmation of four discrete products. Techniques were also developed for the chemical enrichment of toxins produced by P. parvum. Until now, isolation of “prymnesins” has never been reproduced. Polyketide prymnesins possess unique spectral properties that were used to generate an LC-MS fingerprint that comprised 13 ion species. Preliminary investigations using chemifluorimetric methods were also capable of detecting prymnesins in the pico- and nano-molar range. Environmental samples were tested as an independent assessment of these methods. Lastly, the roles of polyketide prymnesins were analyzed with respect to total hemolytic activity (HA) as a function of culture age and salinity. Variation in HA of supernatants was statistically significant relative to both variables (p << 0.05). Salinity was inversely related to HA wherein cultures growing in 5-25 psu were 150-200% more hemolytic. Total HA was inversely related to culture age during the first three weeks, but positively related to it during the next three weeks. Interestingly, no hemolysis was detected in fractions containing prymnesins from culture supernatants and the majority of hemolysins remained in the aqueous phase. Prymnesins extracted from cells varied significantly over the 6-week observation period (p << 0.05); HA was positively correlated during the first half and inversely related during the last half of the study. Salinity was directly related to HA from cell extracts, but these effects were not significantly different until the last three weeks. These investigations suggest that polyketide prymnesins are present at much lower quantities than previously believed, and they may not be the key compounds associated with hemolysis due to P. parvum. / text

Although some physiological effects of toxic metal poisoning have been known for centuries, the specific chemical interactions between biological molecules and mercury(I), mercury(II) or lead(II) are not well understood. To date, only thirteen crystal structures of inorganic mercury-amino acid complexes and six crystal structures of lead-amino acid complexes have been reported with varying degrees of characterization. In order to improve our understanding of the coordination chemistry of mercury and lead in biological environments, a systematic method for the isolation of inorganic metal-amino acid complexes from acidic aqueous solutions has been developed. With this method we have prepared five new lead-amino acid complexes (with L-valine, L-isoleucine, L-phenylalanine, and L-arginine) and four new mercury-amino acid complexes (with L-alanine, D-alanine, L-proline, and N-methyl-L-alanine). These metal-amino acid complexes have been comprehensively characterized in the solid state, solution state and gas phase. The development of this isolation technique in conjunction with the exploration of a number of characterization techniques for studying metal-amino acid interactions greatly enhances the known methods by which metal-biological molecule systems are studied.

Using experimental techniques along with computational fluid dynamics and electrodynamic simulations the performance of the first of three focusing elements in an electrospray macromolecular patterning system was assessed. The performance of this element, the ion funnel, was analyzed by varying the parameters and electric field applied to the system including electrospray emitter to atmosphere-vacuum interface capillary distance, temperature of the desolvating heater, injection rate of solution and the voltage applied to the jet disruption element. Results indicated that processes involved in injecting larger droplets into the chamber resulted in a less effective transmission of the ions through the funnel. Droplet diameter was increased by increasing flow rate and was decreased by increasing the desolvation heater. Varying the voltage applied to the jet disrupting element indicated a peak transmission voltage, when using a 20 mil interface capillary,of 175 V and when using the 30 mil capillary of 180 V. Numerical simulations were in agreement with these values although the widths of these transmission curves were much narrower than the experimental curves.

Pharmaceutical and personal care products (PPCPs) triclosan and nonylphenol, were investigated throughout wastewater treatment in a publicly owned treatment works (POTW). Both compounds react quickly upon chlorination under laboratory conditions, transforming into mono and dichlorinated species. A novel quantitative analytical method employing mass spectrometry was demonstrated on Delaware POTW wastewater samples. Specific transformation products were not detected and the concentration of precursor analytes was not found to be statistically different after treatment. Under tertiary chlorination conditions, transformation products are not produced. ESI-MS was used to explore triply charged, highly hydrated lanthanide ions and charge reduction was directly observed in the MS collision cell. This process proceeded via proton transfer, proved by a strong correlation between the minimum number of water molecules required to stabilize the Ln3+ and the first hydrolysis constant (R2=0.92). The effect of different solvents on the surface activity of ions under electrospray ionization (ESI) was investigated using dilute ionic liquids and the relative surface activity of a given pair of ions could be reversed by moving from a relatively polar solvent to a relatively non-polar one. / Graduate