Button Sample Holders for Infrared Spectroscopy

The design features and applications of button sample holders are described. The similarities and contrasts between the button method and the transmission cell and attenuated total reflection techniques are discussed. Different button sample holder analysis methodologies are outlined, and examples are provided for mid-infrared spectroscopy measurements of solids, liquids, and pastes. Results obtained for 10-nonadecanone powder, a vitamin C tablet, a soil sample, and poly(methyl methacrylate) are used to illustrate different solid sample analysis approaches. Time-dependent spectrum variations detected during evaporation of a blood drop are elucidated and spectra obtained from different quantities of liquid chlorobenzene loaded into buttons and transmission cells are characterized. Infrared spectra derived from three toothpaste brands are compared and a sample perturbation study to identify temperature-dependent changes to the structure of poly(bisphenol A carbonate) is provided as an example of variable temperature infrared spectroscopy.