High‐Sensitivity Analysis of Chrysotile Asbestos Collected From the Working Environment on a Metal Plate Using a Desktop X‐Ray Diffractometer

Chrysotile asbestos was detected at controlled concentrations in the work environment. When a truck‐etched membrane filter was used as the substrate, the chrysotile detection limit was 0.15 μg. To achieve analysis at the control concentration level (0.15 f mL −1 ≧ 1.7 × 10 −6 μg L −1 ) in the work environment, approximately 180,000 L of air must be collected on a 25‐mm‐diameter track‐etched membrane filter. This analysis is practically difficult considering the collection time required. Using a tungsten plate, the detection limit for chrysotile was 30 ng, which was one‐tenth the chrysotile detection limit of the track‐etched membrane filter. Furthermore, experiments in which chrysotile was detached from the membrane filter showed a recovery rate of over 40% on the tungsten plate. Combining these results, chrysotile detection at the management concentration level was possible through X‐ray diffraction after collecting ~45,000 L of air (10 L min −1 for 75 min) on the filter.