Determination of trace elements in hair for monitoring environmental and occupational exposure
type: CreativeWork
description: Hair has a number of advantages over more conventional sample types, such as serum, whole blood and urine, as an indicator of the intake and exposure to trace elements. While the analysis of these conventional sample types can only be used as a measure of recent exposure, hair, in contrast, can provide an historical record of exposure episodes. Furthermore the levels of trace elements in hair are higher than in blood and as a result small changes in intake are magnified. In addition, the collection of hair samples is non-invasive and the samples are easy to store. However, the difficulty in differentiating surface bound contamination from trace elements incorporated into the hair matrix complicates the interpretation of the hair analysis results. A review of the literature showed that a variety of washing procedures to remove external contamination have been proposed but as yet no standardised procedures are available. In this study, methods for the pretreatment and determination of antimony, arsenic, cadmium, chromium, lead, mercury and selenium in human hair by ICP-MS were developed. Chemical speciation of mercury and methyl mercury in hair was also achieved using LC-ICP-MS. For the digestion of hair samples the optimum method for these elements was found to be a digestion mixture of nitric acid and hydrogen peroxide. Certified reference materials CRM 397 and CRM 07601 were digested using this method and the values obtained were seen to be in good agreement with the certified values. Investigations of various washing procedures to remove external contaminants showed that in unexposed hair samples cadmium, lead and mercury were significantly removed from hair using a 0.1M HCl wash, with 87%, 73% and 5% respectively being washed off. Whilst the removal of antimony, arsenic and chromium from unexposed hair was more efficient with 1% v/v sodium lauryl sulphate, with 43%, 40% and 13% of each element respectively being washed off. Selenium could not be removed from the …
abstract: Hair has a number of advantages over more conventional sample types, such as serum, whole blood and urine, as an indicator of the intake and exposure to trace elements. While the analysis of these conventional sample types can only be used as a measure of recent exposure, hair, in contrast, can provide an historical record of exposure episodes. Furthermore the levels of trace elements in hair are higher than in blood and as a result small changes in intake are magnified. In addition, the collection of hair samples is non-invasive and the samples are easy to store. However, the difficulty in differentiating surface bound contamination from trace elements incorporated into the hair matrix complicates the interpretation of the hair analysis results. A review of the literature showed that a variety of washing procedures to remove external contamination have been proposed but as yet no standardised procedures are available. In this study, methods for the pretreatment and determination of antimony, arsenic, cadmium, chromium, lead, mercury and selenium in human hair by ICP-MS were developed. Chemical speciation of mercury and methyl mercury in hair was also achieved using LC-ICP-MS. For the digestion of hair samples the optimum method for these elements was found to be a digestion mixture of nitric acid and hydrogen peroxide. Certified reference materials CRM 397 and CRM 07601 were digested using this method and the values obtained were seen to be in good agreement with the certified values. Investigations of various washing procedures to remove external contaminants showed that in unexposed hair samples cadmium, lead and mercury were significantly removed from hair using a 0.1M HCl wash, with 87%, 73% and 5% respectively being washed off. Whilst the removal of antimony, arsenic and chromium from unexposed hair was more efficient with 1% v/v sodium lauryl sulphate, with 43%, 40% and 13% of each element respectively being washed off. Selenium could not be removed from the …
author: Mawhinney, Jacqueline
language: en
date published: 2000-01
date modified: 2026-07-24T06:31:00Z
provider: Sheffield Hallam University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Sheffield Hallam University