Semi-quantitative powder X-ray diffraction in an instrumental analysis laboratory

CHED 204

Isaac R. Corn, icorn@siue.edu, Masangu Shabangi, mshaban@siue.edu, and Eric J. Voss, evoss@siue.edu. Department of Chemistry, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1652
Although powder X-ray diffraction (PXRD) is widely used for qualitative analysis, quantitative analysis of powders is problematic due to many factors that affect line intensities. In an upper level instrumental analysis laboratory, students have successfully obtained semi-quantitative results using the MDI Jade with Easy-quant software package. Easy-quant is based on the technique of Reference-Intensity-Ratios and peak profiling. In this hands-on experiment, students grind the powders to ensure adequate mixing and small particle size, pack the powders into sample holders, collect PXRD patterns on a Rigaku/MSC MiniFlex+ powder X-ray diffractometer, and analyze the data using Easy-quant. A first unknown is used as an introduction to the technique, and a second unknown challenges students to use deductive and scientific reasoning to identify the compounds and determine the weight percent of each phase. This experiment demonstrates the ease at which non-destructive methods can be used to quantify solid mixtures.
 

General Posters
7:30 PM-9:30 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Chemical Education

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007