Rapid Screening Technique for Detection of Asbestos Fibers in Water Samples

摘要

A rapid screening method is presented that will allow samples containing less than a pre-defined concentration of asbestos fibers to be rejected from further analysis, allowing more detailed transmission electron microscopy characterization to be confined to those samples that have high fiber concentrations. Alignment of asbestos fibers in magnetic fields, combined with measurements of the scattered light from the aligned dispersions, was investigated. A fixed-fiber alignment method and a dynamic method of fiber measurement were studied. The dynamic fiber method proved to be the more sensitive method. Detection limits of 0.5 million fibers per liter (MFL) and 5 MFL were achieved for crocidolite and chrysotile, respectively. These detection limits were achieved directly from the water sample without any preconcentration steps. The scattered light measurement techniques were applied to the determination of the fiber concentrations in drinking water samples from three sources, and the results were consistent with those obtained independently by transmission electron microscopy.