MATRIX-ISOLATION MICROSAMPLING PROCEDURES IN QUANTITATIVE FOURIER-TRANSFORM INFRARED SPECTROMETRY

Techniques for microsampling in infrared spectroscopy by matrix isolation are described. In the matrix isolation of liquid or solid compounds, the sample is vaporized and then diluted with a large excess of a matrix gas; the resulting gaseous mixture is deposited on a cold surface for spectroscopic examination as a solid. Detailed descriptions of the apparatus and procedures employed in the preparation of matrix-isolated samples for qualititive and quantitative analyses by Fourier transform infrared spectrometry are presented. Systems for ″microsampling″ (detection limits for specific compounds approximately equals 0. 5 to 1 mu g) and ″ultramicrosampling″ (detection limits approximately equals 50 to 100 ng) matrix isolation spectroscopy are described. Detection limits and Beer's law behavior for polycyclic aromatic hydrocarbons microsampled by matrix isolation are discussed.