Research on qualitative analysis of serpentine asbestos using TG-DTA-MS

Qualitative analysis of serpentine asbestos in samples such as construction materials using TG-DTA-MS was researched. Dehydration of crystal water of three types of serpentine mineral was observed by thermo MS iongram of m/z = 18 measured by TG-DTA-MS. The peak of dehydration in the thermo MS iongram of chrysotile, which is a type of asbestos, was between 600 and 650 °C. On the other hand, the peak of dehydration of lizardite and antigorite, which are not asbestos, was between 500 and 600 °C and 700 °C or higher, respectively. The same observation was executed on actual samples the respective asbestos content of which was quantified. The results showed the possibility of distinguishing serpentine minerals contained in actual samples by the temperature range of dehydration. JIS A 1481-2 and 3, which are Japanese standard methods for qualitative and quantitative analysis of asbestos in building material products, prescribe the use of XRD to detect and quantify asbestos. However, it is difficult to distinguish chrysotile from the other two non-asbestos serpentine minerals by XRD, which opens the door to misjudgement, such as erroneous determination of non-asbestos samples as asbestos-containing, and overestimation of asbestos content. Observation of dehydration by thermo MS iongram of m/z = 18 measured by TG-DTA-MS was shown to detect such misjudgments.