Milling effects upon quantitative determinations of chrysotile asbestos by the reference intensity ratio method

Abstract

As is well known from literature, the grinding process, which is an unavoidable step in sample preparation, may strongly modify the physical properties of chrysotile through amorphisation. The aim of this work is to establish the proper milling time to apply to the samples before an accurate X-ray powder diffraction quantitative analysis. We have used the RIR (reference intensity ratio) analytical method, based on the measurement of the ratio I/Is between the intensity of the strongest line of an analyte and the intensity of the analytical peak of a standard material, when they are thoroughly mixed 50:50 by weight. We have studied how the RIR value changes as a function of the milling time of the sample and how the accuracy of this quantitative method is affected.

Preparation and Evaluation of a Chrysotile Asbestos-containing Standard Material for Validating X-Ray Diffractometric Quantitation

“…24 In chrysotile asbestos, the diffraction intensities of the chrysotile peaks may be decreased, but the full width at half maximum of the peaks will not be changed by grinding. 12,13 Milling does not affect the crystalline structure of chrysotile asbestos. 12,13 Perlite board powder (30 g) was finely ground using a planetary ball mill.…”

“…12,13 Milling does not affect the crystalline structure of chrysotile asbestos. 12,13 Perlite board powder (30 g) was finely ground using a planetary ball mill. The intensities and the half width of the chrysotile (002) line were measured by varying the grinding time (Fig.…”

“…[4][5][6] In particular, asbestos-containing materials (ACM) were mainly quantified by XRD, as reported in many studies. [7][8][9][10][11][12][13] For phase quantitation, several pure chrysotile materials have been used as calibration standards. In Japan, the JAWE-111 chrysotile standard material issued by the Japan Association for Working Environment Measurement (JAWE), is frequently used.…”

Comparison between Two FT-IR Spectroscopy Analytical Procedures for Micrograms Determination of Asbestos Species in Bulk Materials

“…The Linear Calibration Curve Method (LCM) is commonly used in quantitative chemistry and it has been adopted successfully for the determination of asbestos in bulk materials by means of XRD [4,9]. This analytical procedure can be also used in FT-IR quantitative spectrometry: in this case, the calibration curves are obtained by plotting the intensity of the absorption peak, I M , as a function of the concentration C x (w/w) of the analyte for standard mixtures containing known quantities of a given species of asbestos.…”

Estimation of Purity of Chrysotile Asbestos by X-ray Diffractometry/Rietveld Refinement

“…There are many reports determining chrysotile asbestos concentration quantitatively using a diffractometer. 6,[8][9][10][11][12][13][14][15][16][17] In these studies, asbestos in aerosols was collected using a Ag membrane filter or Zn plate and analyzed using Ag or Zn intensity as a substrate standard to correct the absorption effect. 6,[8][9][10] The amount of asbestos in building materials have been determined by X-ray powder diffractometry with a quantitation limit of 0.5 mass%.…”