Chapter one introduces the historical background, development and need for monitoring techniques utilising absorbent tube sampling methods and highlights the rapid increase in environmental awareness that has occurred as technology has advanced. A short summary covering the sources of volatile organic compounds (VOCs) is included. Chapter two presents a synopsis of the experimental methods and theory associated with adsorbent tube sampling and analysis. The application of both passive and active sampling techniques has been discussed with the emphasis on maintaining sampling and analytical integrity. Chapter three covers the key sources of error in both sampling and analysis and defines statistical terms that are used in analytical science. The measurement and calculation of tube dimensions, diffusion coefficients, mass uptake rates, limit of detection and quantification are presented. Chapter four outlines the findings from an inter-laboratory calibration exercise to investigate external calibration methods at low nanogram levels. The use of certified reference materials and preparation of standards is discussed. Chapters five and six assess the likely errors to be encountered when using passive sampling techniques for long term environmental monitoring, and cover aspects of sampling accuracy, bias and precision. Particular attention is devoted to assessing changes in the mass uptake rate and back diffusion during passive sampling. Chapters seven to ten detail research related to the application of adsorbent tube trapping for the sampling and analysis of VOCs in soil gases. Work has focused on enhancing both the qualitative and quantitative information that can be obtained from soil gas surveys by the use of heated sampling techniques to increase the recovery of less volatile compounds. The feasibility of an indoor test facility to simulate soil and soil gas contamination is also discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:636143 |
| Date | January 1995 |
| Creators | Bradshaw, N. M. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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