Effects of Fine-Fraction Pre-Treatment for Laser Diffraction Particle Size Analysis
Document Type
Oral Presentation
Campus where you would like to present
SURC Ballroom B/C/D
Start Date
21-5-2015
End Date
21-5-2015
Keywords
Geology, Sediment Analysis, Laser Diffraction
Abstract
Pretreatment of sediment samples for particle-size analysis can be costly and time consuming. Here we present results of how various levels of pretreatment affect laser diffraction results. For this study, we subjected 35 sub-samples from seven different stratigraphic layers of the Sanders archaeological site (45KT315) in central Washington State to different combinations of pretreatment (removal of organic and inorganic carbon using 30 percent H2O2 and 1N HCl, respectively, and ultrasonic dispersion). Fully treated samples were presumed to be most accurate and were used as the test control. As expected, completely untreated samples exhibited excess coarse-sized particles (i.e., most negatively skewed). Other results demonstrate inter- and intra-sample variations that are likely due to differences in physical and chemical properties of each sample. No clear patterns emerge that lead us to conclude anything other than full pretreatment is required for best results.
Recommended Citation
Johnson, Matt and Walton, Lauren, "Effects of Fine-Fraction Pre-Treatment for Laser Diffraction Particle Size Analysis" (2015). Symposium Of University Research and Creative Expression (SOURCE). 103.
https://digitalcommons.cwu.edu/source/2015/posters/103
Poster Number
49
Department/Program
Resource Management
Additional Mentoring Department
Anthropology & Museum Studies
Additional Mentoring Department
McNair Scholars
Effects of Fine-Fraction Pre-Treatment for Laser Diffraction Particle Size Analysis
SURC Ballroom B/C/D
Pretreatment of sediment samples for particle-size analysis can be costly and time consuming. Here we present results of how various levels of pretreatment affect laser diffraction results. For this study, we subjected 35 sub-samples from seven different stratigraphic layers of the Sanders archaeological site (45KT315) in central Washington State to different combinations of pretreatment (removal of organic and inorganic carbon using 30 percent H2O2 and 1N HCl, respectively, and ultrasonic dispersion). Fully treated samples were presumed to be most accurate and were used as the test control. As expected, completely untreated samples exhibited excess coarse-sized particles (i.e., most negatively skewed). Other results demonstrate inter- and intra-sample variations that are likely due to differences in physical and chemical properties of each sample. No clear patterns emerge that lead us to conclude anything other than full pretreatment is required for best results.
Faculty Mentor(s)
Patrick Lubinski, Ian Buvit