Chemometrics

Leeching of Silver from Silver-Impregnated Food Storage Containers

Food storage containers may contain micro-particles of Ag, which serves as an anti-microbial agent to limit the growth of molds, fungi, and other microorganisms. Students study the leeching ability of three solvents — deionized water, tap water, and acetic acid — by measuring the concentration of silver in the leechate using graphite-furnace atomic absorption spectrophotometry. An analysis of variance is used to evaluate the relative importance of container type, solvent, extraction time, and the application of heat during the extraction.

The full citation is here: Hauri, J. F., Niece, B. K.  J. Chem. Educ. 2011, 88, 1407–1409 and a link to the article is provided below (subscription to the journal required).

http://dx.doi.org/10.1021/ed101042y

To See the World in a Grain of Sand: Recognizing the Origin of the Sand Specimens by DRIFT and Multivariate Exploratory Analysis

Students use DRIFT spectra and multivariate analysis to characterize sands collected from different locations. A principal component analysis shows that the scores for the first and fourth principal component allows students to identify samples collected from different areas. The scores plot distinguishes between samples that are carbonate-rich and that are silicate-rich. For carbonate-rich samples, it is possible to distinguish between those that are dolomite-rich and those that are not; for the silicate-rich samples there is some separation between those samples rich in quartz and those rich in feldspar.

The full citation is here: De Lorenzi Pezzolo, A.  J. Chem. Educ. 2011, 88, 1304–1308 and a link to the article is provided below (subscription to the journal required).

http://dx.doi.org/10.1021/ed9000409