Field portable X-Ray fluorescence for rapid analysis Of titanium dioxide on air filters

Field portable X-Ray fluorescence for rapid analysis Of titanium dioxide on air filters. ii ACKNOWLEDGMENTS This study would not have been possible without the help from several different resources. I would like to thank Kent Candee for the access to the field portable x-ray fluorescence analyzer, which was my biggest concern from the beginning of the project. I would also like to thank Pam Kostle for the guidance she provided for sample analysis. I have to thank all my professors, fellow students, and lab group during the last two years for my valuable education. A special thank you goes to my committee members Dr. O'Shaughnessy and Dr. Nonnenmann for their input and for being so accommodating during this final process. Last, but not least, I would like to give the most deserved thank you to Dr. Thomas Peters for serving as my advisor during graduate school and for his constant patience and guidance. iii ABSTRACT Field portable x-ray fluorescence (FPXRF) was evaluated as a method for screening titanium dioxide (TiO 2) on air filters. Mixed cellulose ester (MCE) and polycarbonate (PC) filter types were compared to gravimetric filters to determine if there was a benefit of using one over the other during FPXRF analysis. No significant difference (p-value = 0.92) was found between MCE and PC filters for FPXRF. MCE filters had a higher coefficient of determination (R 2 = 0.97) with the FPXRF analyzer than the PC filters (R 2 = 0.70) when compared to gravimetric filter results. The limit of detection (LOD) and limit of quantitation (LOQ) of the FPXRF analyzer were determined through the analysis of blank filters and filters with low levels of TiO 2 analyte. The LOD for TiO 2 using filter blanks was 7.3 µg/filter, and 25 µg/filter with low levels of TiO 2 analyte. The LOQ was 12.8 µg/filter determined with filter blanks, and from the low level analyte samples was 0.82 µg/filter. Filter samples were collected at varying TiO 2 concentrations and submitted to FPXRF and inductively couple plasma – mass spectrometry (ICP-MS) analysis. Linear regression was used to determine the relationship between the two methods for TiO 2 assessment. A high coefficient of determination (R 2 = 0.90) was found between FPXRF and ICP-MS at lower TiO 2 concentrations while a low coefficient of determination (R 2 = 0.24) was shown for the high TiO 2 concentrations. Statistical analysis was used …