Abstract

This study is to quantify α-quartz, cristobalite and kaolinite using by FTIR in respirable dust generated in the mining workplace. Various minerals in mines can interfere with peaks when quantifying respirable crystalline silica by FTIR. Therefore, for accurate quantification, it is necessary to remove interfering substances or correct the peaks that cause interference. To confirm the peaks occurring in α-quartz, cristobalite and kaolinite, each standard material was diluted with KBr and scanned in the range of 400 cm1 to 4000 cm1 using by FTIR. As a result of scanning the analytes, it was decided to use the peaks of 797.66 cm1 and 695.25 cm1 for α-quartz, 621.58 cm1 for cristobalite, and 3696.47 cm-1 for kaolinite. When the above materials are mixed, interference occurs at the peak for quantification, which is corrected by the calculation formula. The analysis of the mixture of α-quartz and cristobalite shows the average bias (%) of 2.64 (corrected) at α-quartz (797.66 cm1), 5.61 (uncorrected) at α-quartz (695.25 cm1) and 1.51 (uncorrected) at cristobalite (621.58 cm1). The analysis of the mixture of α-quartz and kaolinite shows the average bias(%) of 1.79(corrected) at α-quartz (797.66 cm1), 3.92 (corrected) at α-quartz (695.25 cm1) and 2.58 (uncorrected) at kaolinite (3696.47 cm1). The analysis of the mixture of cristobalite and kaolinite shows the average bias (%) of 2.15 (corrected) at cristobalite (621.58 cm1), 4.32 (uncorrected) at kaolinite (3696.47 cm1). The analysis of the mixture of α- quartz and cristobalite and kaolinite shows the average bias (%) of 1.93(corrected) at α-quartz (797.66 cm1), 6.47 (corrected) at α-quartz (695.25 cm1) and 1.77 (corrected) at cristobalite (621.58 cm1) and 2.61 (uncorrected) at kaolinite (3696.47 cm1). The experimental results showed that the deviation caused by peak interference by two or three substances could be corrected to less than 6 % of the average deviation. This study showed the possibility of correcting and quantifying when various interfering substances that are difficult to remove are mixed.