Quantitation of Trace Residues in Clandestine Laboratory Investigation and Remediation

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dc.contributor.advisor Miskelly, Gordon en
dc.contributor.advisor Elliot, Douglas en
dc.contributor.author Abdullah, Ahmad Fahmi Lim en
dc.date.accessioned 2018-09-09T23:29:26Z en
dc.date.available 2018-09-09T23:29:26Z en
dc.date.issued 2007 en
dc.identifier.uri http://hdl.handle.net/2292/37673 en
dc.description Full text is available to authenticated members of The University of Auckland only. en
dc.description.abstract The number of clandestine methamphetamine laboratories discovered in New Zealand is on the rise, with a total of 211 clandestine laboratories being dismantled in the 2006 calendar year. These laboratories pose a significant danger to the general public due to their physical, chemical and environment hazards. This study has developed methods appropriate for sampling and analysing Iow levels of methamphetamine, pseudoephedrine and iodine under conditions such as could be encountered at a clandestine methamphetamine laboratory. Although analysis of methamphetamine and pseudoephedrine is routine, the application of these analyses to very Iow levels in environmental extracts is not as well developed. The major part of this study looked at the recovery of pseudoephedrine and methamphetamine from glass, stainless steel, and a range of other surfaces likely to be found in a clandestine laboratory (Formica, kitchen top tile, painted metal, varnished wood and floor wood). Analysis of trace-level pseudoephedrine showed interference from carbonyl-containing compounds, expecially formaldehyde. In our hands, standard TFAA derivatisation did not completely react with the pseudoephedrine-formaldehyde coumpound. Therefore, an alternative derivatisation strategy with cyclohexanone was used, which could analyse both pseudoephedrine and pseudoephedrine-formaldehyde. The results show that pseudoephedrine free base has significant volatili• ty at room temperature, wi• th >80% of a 2.5 μg∕/8 0 cm 2 sample being Iost in two days. The pseudoephedrine hydrochloride salt, while Iess volatile, still volatilised to a significant extent, with up to 40% being found on a plate positioned above a surface concentration of 2 μg∕80 cm2. Similar recoveries of pseudoephedrine were observed for most surfaces examined, although surface painted with polyester cross-linked with melamine showed much lower recoveries (<10%) suggesting reaction of pseudoephedrine with the polymer. Our results show that surface wiping with water-dampened filter paper can recover 60-80% of pseudoephedrine immediately after deposition, and at least 50% of the pseudoephedrine still present on a surface after 2 days. Analysis of methamphetamine did not show the interference shown by pseudoephedrine, so a standard TFAA derivatisation could be used. Methamphetamine showed similar volatility to pseudoephedrine, even though it is theoretically predicted to be more volatile. Methamphetamine could be recovered by surface wiping with methanol-dampened filter paper with 60-90% recovery shortly after deposition, and at least 50-60% of the methamphetamine still present on surfaces could be recovered after 2 days. The recovery of methamphetamine and pseudoephedrine were not affected by the presence of iodine in solution or on surfaces using the basic extraction protocol followed by cyclohexanone (pseudoephedrine) or TFAA (methamphetamine) derivatisation, and GC-MS analysis. This means that reliable results for these analytes can be obtained from surfaces showing iodine staining. A reported method for iodine analysis using ΛζτV-dimethylaniline and GC-MS was adapted for trace-level analysis and discrimination of airborne and surface I2 and Γ. This method gave good recoveries (>80%) of airborne iodine, but surface wiping only recovered 20% (filter paper) or 50% (glass fibre filter paper) of the I2 deposited on an inert surface. These recoveries were reproducible, so surface wiping could still give indicative results. Iodine deposited on glass, stainless steel, Formica or kitchen top tile faded rapidly upon the drying of the solvent. No visible stains were visible after 15 min, and only trace levels of total iodine (<200 ng 1/100 cm2) could be recovered by surface wipes after two days at room temperature. This iodine was present as Γ, suggesting that iodine was reduced to iodide even on a cleaned glass surface. A direct trapping and derivatisation strategy was used to analyse airborne iodine. The amount of iodine present in the atmosphere of a glass chamber during evaporation of a 1 mg/mL solution of iodine in methanol peaked at the time of complete solvent evaporation and then decreased rapidly, indicating Ioss 0fI2 to the container wall. Methanolic iodine stains on vinyl slowly released I2 to the air over 32 h suggesting that the iodine absorbed by the vinyl was slowly desorbed. Only trace levels of iodine (mainly present as Γ) were detected from the surface wipes of this stain suggesting that the iodine is not simply adsorbed on this surface but that the iodine is dissolved inside the material. Therefore, for such substrates, a surface wipe may not give adequate indication of iodine staining. The current practice of identifying I2 contamination by visual examination is appropriate, especially for light-coloured surfaces. en
dc.language en en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof PhD Thesis - University of Auckland en
dc.relation.isreferencedby UoA99180410114002091 en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. en
dc.rights Restricted Item. Available to authenticated members of The University of Auckland. en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.title Quantitation of Trace Residues in Clandestine Laboratory Investigation and Remediation en
dc.type Thesis en
thesis.degree.grantor The University of Auckland en
thesis.degree.level Doctoral en
thesis.degree.name PhD en
dc.rights.holder Copyright: The author en


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