APPLICATION OF DIFFUSE-REFLECTANCE INFRAR ED-SPECTROSCOPY FOR THE QUANTITATIVE-DETERMINATION OF INORGANIC-COMPOUNDS .1. OPTIMIZATION OF SAMPLE PREPARATION

Optimization of sample preparation for diffuse reflectance IR spectros copy has been carried out in order to obtain reproducible results and linear calibration curve between the Kubelka-Munk function and the sam ple concentration. The optimum conditions for sample preparation were found to be as follows: 1. The quantity of the sample is just enough t o fill the sample cup perfectly and the mass of the sample is controll ed within +/- 2%. 2. The sample packing is performed using 1 MPa press ure for 1 min. 3. The sample thickness is greater than or equal to 2 m m and thus the criterion of ''infinite sample thickness'' is practical ly fulfilled.