High precision and spatial analysis of platinum, palladium, and rhodium in catalytic converters by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry

Persistent Link:
http://hdl.handle.net/10150/282792
Title:
High precision and spatial analysis of platinum, palladium, and rhodium in catalytic converters by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry
Author:
Pennebaker, Frank Martin, 1970-
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The accuracy and precision of catalytic converter analysis using conventional analytical methodology such as fire assay, x-ray fluorescence, atomic absorption and ICP-AES are typically in the range of ±7-10% RSD. Due to the high cost of noble metals, methods of analysis with increased accuracy and precision are desired to evaluate the loading of noble metals onto converter bricks. The investigations described in this work have resulted in a better understanding of many of the inherent problems and have contributed new approaches for sample dissolution and analysis using array detector based Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). These methods are shown to be accurate and precise for the analysis of Pt, Pd, and Rh in catalytic converters. Catalytic converters are difficult to dissolve by conventional acid methodology. While carius, tubes have previously been employed to dissolve small weights of sample, complete dissolution of increased amounts of sample, as needed for high precision ICP-AES analysis, has been hindered by the insufficient oxidation potential of the acids in the carius tube. In this work, the addition of ferric chloride is shown to increase the dissolving power of the carius tube method and specifically targets Pt, Pd and Rh for dissolution. Simultaneous collection of analyte wavelengths and simultaneous background correction, as performed with multichannel array detector ICP-AES instrumentation, have enhanced sensitivity and precision in catalytic converter analysis when compared to single channel instrumentation. The studies described within this dissertation demonstrate that flicker noise has been effectively eliminated through the use of multichannel array based ICP-AES instrumentation. With proper line selection and the use of the high-resolution system, Pt, Pd and Rh in catalytic converters can be analyzed with precision of 1-1.5%. ICP-AES accuracy has been confirmed through isotope dilution ICP-MS employing new methodology to avoid Zr isobaric interferences.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Analytical.; Engineering, Automotive.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Denton, M. Bonner

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleHigh precision and spatial analysis of platinum, palladium, and rhodium in catalytic converters by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometryen_US
dc.creatorPennebaker, Frank Martin, 1970-en_US
dc.contributor.authorPennebaker, Frank Martin, 1970-en_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe accuracy and precision of catalytic converter analysis using conventional analytical methodology such as fire assay, x-ray fluorescence, atomic absorption and ICP-AES are typically in the range of ±7-10% RSD. Due to the high cost of noble metals, methods of analysis with increased accuracy and precision are desired to evaluate the loading of noble metals onto converter bricks. The investigations described in this work have resulted in a better understanding of many of the inherent problems and have contributed new approaches for sample dissolution and analysis using array detector based Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). These methods are shown to be accurate and precise for the analysis of Pt, Pd, and Rh in catalytic converters. Catalytic converters are difficult to dissolve by conventional acid methodology. While carius, tubes have previously been employed to dissolve small weights of sample, complete dissolution of increased amounts of sample, as needed for high precision ICP-AES analysis, has been hindered by the insufficient oxidation potential of the acids in the carius tube. In this work, the addition of ferric chloride is shown to increase the dissolving power of the carius tube method and specifically targets Pt, Pd and Rh for dissolution. Simultaneous collection of analyte wavelengths and simultaneous background correction, as performed with multichannel array detector ICP-AES instrumentation, have enhanced sensitivity and precision in catalytic converter analysis when compared to single channel instrumentation. The studies described within this dissertation demonstrate that flicker noise has been effectively eliminated through the use of multichannel array based ICP-AES instrumentation. With proper line selection and the use of the high-resolution system, Pt, Pd and Rh in catalytic converters can be analyzed with precision of 1-1.5%. ICP-AES accuracy has been confirmed through isotope dilution ICP-MS employing new methodology to avoid Zr isobaric interferences.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Analytical.en_US
dc.subjectEngineering, Automotive.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorDenton, M. Bonneren_US
dc.identifier.proquest9912094en_US
dc.identifier.bibrecord.b39122542en_US
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