Doctor of Philosophy
This dissertation describes the development of a novel 3D printed fluorescence detector and a 3D printed chemiluminescence detector. The 3D printed fluorescence detector is used as a component of the haloacetic acid rapid-response (HAA-RR), a commercial system for the analysis of haloacetic acids (HAAs) in drinking water. The 3D printed chemiluminescence detector was used in the development of a free-available chlorine (FAC) analyzer and a lead (II) analyzer.The 3D printed fluorescence detector was developed for the specific application of the nicotinamide chemistry used in the HAA-RR. The detector is simple, rugged and inexpensive. The detector was compared to a commercially available Waters 474 dual monochromator detector. An MDL, accuracy and precision study was performed using the fluorescent reagent nicotinamide with the detectors in series. In addition, signal-to-noise ratios for the detectors were compared. The 3D printed fluorescence detector performed comparably, if not better, than the Waters detector. The 3D printed fluorescence detector may be used for any application requiring quantitative fluorescence detection by changing the excitation and emission filters.The first commercial automated analyzer for HAAs analysis in drinking water was developed. The HAA-RR is a commercial version of a previously reported, laboratory-grade analyzer. Components of the HAA-RR are discussed such as the post-column reagent delivery system and a low-cost, low-pressure gradient system. The 3D printed fluorescence detector is used as a detector in the HAA-RR system. MDL, accuracy and precision studies for the HAA-RR are compared to the laboratory-grade analyzer. Results of HAAs analysis from a beta test at the Lebanon, TN water treatment plant are presented where multiple methods of calibration were performed and compared. A side-by-side comparison study of the HAA-RR and the United States Environmental Protection Agency method 552.3 is presented for the analysis of HAAs for the Lebanon, TN water treatment plants quarterly compliance monitoring. Also, parameters were investigated and established to be used as daily quality control (QC) monitors for the HAA-RR. The parameters selected for the QC monitoring were: retention time, capacity factor and peak width at 50 % maximum height for the internal standard, (2-bromobutanoic acid) and the retention time of the unretained component. A (FAC) analyzer was developed using gas-diffusion flow injection analysis and detection with a 3D printed chemiluminescence detector. The FAC analyzer is able to detect microgram per liter concentrations of FAC in the presence of milligram per liter concentrations of chlorine dioxide with a sample preparation step. Multiple different fits of the FAC calibration were evaluated, and a base 10 log-log fit was the most fitting. An MDL, accuracy and precision study was performed over FAC concentrations of 1.0 to 16.0 mg L-1, with a check standard at 2.0 mg L-1. The USEPA estimated MDL of the FAC analyzer is 0.07 mg L-1. The FAC analyzer was used for the analysis of real-world samples of commercially-available chlorine dioxide, reporting no detected concentration of FAC.Preliminary development of a flow-injection system for the detection of lead (II) in drinking water is presented. The lead (II) analyzer uses luminol-hydrogen peroxide chemiluminescence for the detection of lead (II) ion with a 3D printed chemiluminescence detector. Optimization of the reagent concentrations was carried out, along with a linearity study and a preliminary MDL, accuracy and precision study. The preliminary study of the method reported poor precision high mean percent recovery for the check standard due to the check standard of 15 g L-1 Pb2+ ion being near the MDL of 16 g L-1 Pb2+. The preliminary studies of the lead (II) analyzer are promising, and proof-of-concept was demonstrated.
Dissertation or thesis originally submitted to ProQuest
Snow, Robyn Ann, "Development and Application of 3D Printed Detectors for Environmental Analysis" (2019). Electronic Theses and Dissertations. 2965.