Detection and determination of chrysotile in talc USP

Our plain-English summary of Detection and determination of chrysotile in talc USP, by H.A. Rose (Journal of Pharmaceutical Sciences, 1974).

The study

• Author: H.A. Rose
• Journal: Journal of Pharmaceutical Sciences
• Published: 1974;63(2):268-9
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This 1974 laboratory paper described a method, developed by the author, for detecting and measuring chrysotile asbestos as an impurity in talc USP (talc meeting the United States Pharmacopeia standard), which the article notes is widely used as a dusting powder and in capsule contents. No people were studied. The test relied on chrysotile taking up (adsorbing) a dye, bromcresol purple, while talc did not. The dye left in solution was then measured with a spectrophotometer. Known small amounts of chrysotile (about 3 mg and 6 mg) were added to 200-mg talc samples, and the chrysotile already in the talc was worked out from the resulting graph. In a typical run on talc spiked with 0.5% chrysotile, the assay indicated 1.1 mg chrysotile in a 200-mg sample, or 0.55%. A second chrysotile sample gave substantially the same adsorption behavior as the first. The author concluded that the assay is useful at least at the level of 0.5% chrysotile. The author noted that the test does not detect amphibole asbestos such as tremolite, and that all precision tests were done on spiked samples.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory analytical method development: a dye-adsorption and spectrophotometric test for chrysotile in talc, using known additions of chrysotile to the sample (an internal standard approach). No human subjects.
• Who was studied: Samples of talc USP, some with accurately weighed additions of chrysotile (about 3 mg and about 6 mg). The precision tests were done on spiked samples. The work came from the Analytical Development Department, Eli Lilly and Company, Indianapolis; the paper was received in 1973.
• Exposure: Chrysotile as a contaminant of talc. Chrysotile samples were supplied by the Johns Manville Research Center and by Indiana University. Amphibole asbestos such as tremolite was not covered by the test.
• Main results:
  • The chrysotile content of the talc was found by plotting absorbance against the amount of chrysotile added and extending the line back to a baseline set by the blank.
  • In a typical determination on talc spiked with 0.5% chrysotile, the assay indicated 1.1 mg chrysotile in a 200-mg sample, or 0.55%.
  • A second chrysotile sample, obtained to rule out a peculiarity of the first, gave substantially the same dye adsorption behavior.
• The authors' conclusion: The author concluded that the assay is useful at least at the level of 0.5% chrysotile in talc USP, and that its internal standard method removes the need for a standard calibration curve.
• Limitations the authors state:
  • The test detects chrysotile but not amphibole types of asbestos such as tremolite.
  • All precision tests were done on spiked samples, with a limited number of determinations.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Chrysotile, Talc.

Related studies

• Mineralogical features associated with cytotoxic and proliferative effects of fibrous talc and asbestos on rodent tracheal epithelial and pleural mesothelial cells — A.G. Wylie, H.C. Skinner, et al. (1997)
• Identification and quantitation of asbestos in talc — A.N. Rohl, A.M. Langer (1974)
• Characterization of talc and associated minerals — D.H. Hamer, F.R. Rolle, et al. (1976)
• Evaluation by electron microscopy techniques of asbestos contamination in industrial, cosmetic, and pharmaceutical talcs — L. Paoletti, S. Caiazza, et al. (1984)
• Talc dust pneumoconiosis — A. Berner, B. Gylseth, et al. (1981)
• Asbestos in talc — A.N. Rohl (1974)

Browse return to medical research.