Extraction methods for assessing the bioaccessibility of potentially toxic elements in urban airborne particulate matter by inductively coupled plasma mass spectrometry

  • Jawad Ali Hussein ALPOFEAD

Student thesis: Doctoral Thesis

Abstract

Inhaled particulate matter (PM), containing bioaccessible potentially toxic elements (PTE) has attracted attention due to potential human health risk. This study was to develop and assess the suitability of simplified bioaccessibility extraction test (SBET) and the stomach phase of unified bioaccessibility method (UBMSG) to measure bioaccessible PTE in PM10 collected on filter dynamic measurement system (FDMS) filters used worldwide. Analytes were As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn and measured by ICP-MS.The SBET and UBMSG were miniaturised for application to PM10. Reducing sample mass and reagents volume by a factor of 10 for the SBET and by a factor of 6 for UBMSG, and presence of the FDMS filter did not affect PTE extractabilities. Bioaccessible PTE in blank FDMS filters were generally low, except for Zn. Washing acrodisc® syringe filters immediately before use with 80 mL of glycine reduced the concentration of Cu and Zn in procedural SBET blanks from 119 and 1520 to 0.129 and 14.5 μg L-1, respectively.New closed-loop and single-pass dynamic models for the SBET and UBMSG either coupled or not with ICP-MS were successfully applied to determine bioaccessible PTE in real and simulated PM10 samples. Accuracy of models was ascertained by mass balance, and verified by Z-scores, which were generally acceptable. For single-pass models, rapid mobilization was observed for PTE, except for Cr.Finally, a new artificial mucus fluid was applied sequentially with the SBET and UBMSG (gastric fluid only) to measure bioaccessible PTE in inhaled PM10. Bioaccessible PTE concentrations, which were underestimated for As, Cr, Cu, and Pb, and overestimated for Cd, Fe, Ni and Zn using ingestion route alone, were more accurately determined. Extraction methods that are more similar to real body processes were successfully created to determine bioaccessible PTE in PM10 that are inhaled and subsequently ingested.
Date of Award1 Nov 2016
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorChristine Davidson (Supervisor) & David Littlejohn (Supervisor)

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