Estimating Community Drug Usage Patterns by the Analysis of Waste Water
4. Stability Trials
A mixed drug standard was derivatised and reconstituted in methanol. A portion of this was used for a 14 hour autosampler stability study and another portion was used for storage stability studies at -20°C and 4°C over 6 weeks. Initial observed trends indicate that the amphetamine type stimulants and their analogues are stable under these conditions of testing. This follows a trend observed for silylated illicit drugs which were found to be stable for at least 1 week at -20°C (González-Mariño, et al., 2010).
In Figure 4, methylenedioxymethamphetamine (MDMA), methylbenzodioxolylbutanamine (MBDB),1-(4-Trifluoromethylphenyl) piperazine (4-TFMPP) and 1-(4-Methoxyphenyl) piperazine (4-MPP) show stability over the 14 hour period. The peak area ratio for these analytes did not vary over time. On the other hand, ecgonine methyl ester, cannabinol & Δ9- Tetrahydrocannabinol showed degradation over the 14 hour period evidenced by the reduction in height and peak area ratio of the respective peaks with time. However, further autosampler stability studies over a longer time period (24 hours) will be conducted for further evaluation. Full data is available on request.
In Figure 5, MDMA, MBDB, 4-TFMPP & 4-MPP show stability over a 6 week period at 5°C and -20°C as indicated by their PARs. The results from the stability studies indicate the importance of storing samples at temperatures between -20°C and 5°C. This has been collaborated by published studies which all utilize storage of positive controls or waste water samples at the above temperatures (Kasprzyk-Hordern, et al., 2007; Postigo, et al., 2011)
Figure 4: 14 hour autosampler stability of MDMA, MBDB, 4-TFMP, and 4-MPP
Figure 5: Storage stability of MDMA, MBDB, 4-TFMP, and 4-MPP at 5°C and -20°C.
5. Conclusion
From the preliminary investigations, a GC-MS method capable of simultaneously detecting 31drugs from different classes in a mixed standard as well as from spiked water samples has been developed. This combination of target analytes with geographical location for sampling has not been investigated before. In addition, the use of LLE and GC-MS as analytical tools for the extraction and detection of the investigated illicit drugs in waste water samples has not been reported before.
For improved chromatographic and spectrometric parameters, acylation with PFPA:ethyl acetate was selected over silylation and alkylation. The combination of parameters such as peak shape, retention times, retention indices, and an increase in the number of diagnostic ions with a higher m/z indicate the method is suitable for simultaneous detection of the studied drugs of abuse. Although complete derivatisation was achieved at 80°C for 45 minutes, further optimization to reduce analysis time will need to be conducted.
LLE and SPE methods have been compared to evaluate suitability for the target drugs. For SPE, the method based on strong cationic exchange, Oasis MCX®, has been selected for further optimization studies due to higher recoveries and detection of target analytes over other SPE cartridges. For LLE, the method based on chloroform:ethyl acetate:ethanol has been selected for further optimization studies. Initial indications show better recoveries, repeatability & speed of analysis with LLE over SPE. All internal standards spiked into untreated waste water were detected as a further indication of the suitability of the tested SPE and LLE methods.
Autosampler studies have shown certain drugs to be more stable than others over a 14 hour period. Amphetamine type stimulants such as MDMA, MBDB, 4-TFMPP and 4-MPP, are more stable than drugs such as ecgonine methyl ester and Δ9-Tetrahydrocannabinol. Storage stability studies of the PFPA-derivatised mixed drug standard over a 6 week period have shown stability for the majority of drugs. Hence samples can be safely stored in derivatised form for upto 6weeks before analysis. A point to note is that analysis after derivatisation is
normally done immediately after or within 1 week at the most. However, knowing that the derivatised drugs are stable for a much longer period is of an advantage due to the lack of breakdown products which can interfere with detection especially if the samples need to be re-analysed. There was little observable difference in the PARs between storage at 5°C and - 20°C. Once extraction methods are optimized, stability of the mixed drug standards in untreated waste water will be evaluated to determine storage conditions of the unprocessed sample.
Further work towards method development will include optimization of derivatisation conditions, optimization of SPE and LLE methods using untreated waste water, optimization of instrumental parameters using SIM and splitless injection, and linearity. Upon validation, the analytical method will be applied to raw untreated waste water in order to determine the usage pattern of drugs within a particular community.
Acknowledgements
The author acknowledges the Department of Life Sciences at Anglia Ruskin University for financial support on this project. Special thanks also goes to Rick Mister and Rosie Felton from Anglian Water for supplying water samples. I would also like to thank Joanne Hooson and Kevin Bright for their ongoing technical support. Also acknowledged is Chipo Kuleya for her collaboration on the early phases of the method development.
References
Babushok, V.I., et al., 2007. Development of a database of gas chromatographic retention properties of organic compounds. Journal of Chromatography A, 1157, pp.414–421. Blau, K. and Halket, J. eds., 1993. Handbook of Derivatives for Chromatography. 2nd Ed.
Chichester: John Wiley & Sons Ltd.
Boles, T.H. and Wells, M.J.M, 2010. Analysis of amphetamine and methamphetamine as emerging pollutants in wastewater and wastewater-impacted streams. Journal of Chromatography A, 1217, pp.2561-2568
Bones, J., Thomas, K.V., Paull, B., 2007. Using environmental analytical data to estimate levels of community consumption of illicit drugs and abused pharmaceuticals. Supplementary Material (ESI) for the Journal of Environmental Monitoring, 9(7), pp. 701-7.
Castiglioni, S. et al., 2008. Mass spectrometric analysis of illicit drugs in wastewater and surface water. Mass Spectrometry Reviews, 27(4), pp.378-94.
Fatta, D., Nikolaou, A., Achilleos, A., Meriç, S., 2007. Analytical methods for tracing pharmaceutical residues in water and wastewater. Trends in Analytical Chemistry, 26(6), pp.515-533
González-Mariño, I., Quintana, J.B., Rodríguez, I., Cela, R., 2010. Determination of illicit drugs in water by solid-phase extraction, derivatisation and gas chromatography-ion trap- tandem mass spectrometry. Journal of Chromatography A, 1217(11), pp.1748-60.
Heath, E., et al., 2010. Second interlaboratory exercise on non-steroidal anti-inflammatory drug analysis in environmental aqueous samples. Talanta, 81, pp. 1189-1196.
Jjemba, P.K., 2008. Pharma-Ecology: The Occurrence and Fate of Pharmaceuticals and Personal Care Products in the Environment. [e-book] New Jersey: John Wiley & Sons. Available through : Anglia Ruskin University Library <http://libweb.anglia.ac.uk> [Accessed 20 August 2011].
Kasprzyk-Hordern, B., Dinsdale, R.M., Guwy, A.J., 2007. Multi-residue method for the determination of basic/ neutral pharmaceuticals and illicit drugs in surface water by solid- phase extraction and ultra performance liquid chromatography–positive electrospray ionisation tandem mass spectrometry. Journal of Chromatography A, 1161, pp.132-145.
Kasprzyk-Hordern, B., Dinsdale, R.M., Guwy, A.J., 2009a. Illicit drugs and pharmaceuticals in the environment-forensic applications of environmental data. Part 1: Estimation of the usage of drugs in local communities. Environmental Pollution, 157(6), pp.1773-7.
Kasprzyk-Hordern, B., Dinsdale, R.M., Guwy, A.J., 2009b. Illicit drugs and pharmaceuticals in the environment-forensic applications of environmental data, Part 2: Pharmaceuticals as chemical markers of faecal water contamination. Environmental Pollution, 157(6), pp.1778-86.
Lavagnini, I., et al., 2006. Quantitative Applications of Mass Spectrometry. Chichester: John Wiley & Sons Ltd.
Levine, B. ed., 2006. Principles of Forensic Toxicology. 2nd Ed. Washington, DC: American Association of Clinical Chemistry.
Mari, F., et al., 2009. Cocaine and heroin in waste water plants: a 1-year study in the city of Florence, Italy. Forensic Science International,189(1-3), pp. 88-92.
Measham, F., Moore, K., Newcombe, R., Welch, Zoe., 2010. Tweaking, bombing, dabbing and stockpiling: the emergence of mephedrone and the perversity of prohibition. Drugs and Alcohol Today, 10(1), pp.14-22.
Meyer, M.R., Wilhelm, J., Peters, F.T., Maurer, H.H., 2010. Beta-keto amphetamines: studies on the metabolism of the designer drug mephedrone and toxicological detection of mephedrone, butylone, and methylone in urine using gas chromatography-mass spectrometry. Analytical & Bioanaytical Chemistry 397, pp.1225–1233.
Moffat, A.C., Osselton, M.D., Widdop, B., and Watts, J., eds., 2011. Clarke‘s Analysis of Drugs and Poisons. 4th Ed. London: Pharmaceutical Press.
Nödlera, K., Licha, T., Bester, K., Sauter,M., 2010. Development of a multi-residue analytical method, based on liquid chromatography–tandem mass spectrometry, for the simultaneous determination of 46 micro-contaminants in aqueous samples. Journal of Chromatography A, 1217, pp. 6511–6521.
Peters, T.F., et al., 2003. Screening for and validated quantification of amphetamines and of amphetamine- and piperazine-derived designer drugs in human blood plasma by gas chromatography/mass spectrometry. Journal of Mass Spectrometry, 38, pp.659-676. Postigo, C., López de Alda, M.J, Barceló, D., 2011. Evaluation of drugs of abuse use and
trends in a prison through wastewater analysis. Environment International, 37, pp.49–55. Raikos, N., et al., 2009. Development of a Liquid-Liquid Extraction Procedure for the
Analysis of Amphetamine in Biological Specimens by GC-FID. The Open Forensic Science Journal, 2, pp.12-15.
Sebok, A., et al.,2009. Multiresidue analysis of pollutants as their trimethylsilyl derivatives by gas chromatography-mass spectrometry. Journal of Chromatography A, 1216, pp2288- 2301.
Staack, R.F., 2007. Piperazine designer illicit drugs. Lancet, 369, pp.1411.
Staack, R.F., Maurer, H.H., 2004. New designer drug 1-(3,4- methylenedioxybenzyl)piperazine (MDBP): studies on its metabolism and toxicological detection in rat urine using gas chromatography/mass spectrometry. Journal of Mass Spectrometry, 39, pp255–261.
Telepchak, M. J. August, T. F. and Chaney, G. eds., 2004. Forensic Science and Medicine: Forensic and Clinical Applications of Solid Phase Extraction. New Jersey: Humana Press Inc.
Tsutsumi, H., et al., 2005. Development of simultaneous gas chromatography–mass spectrometric and liquid chromatography–electrospray ionization mass spectrometric determination method for the new designer drugs, N-benzylpiperazine (BZP), 1-(3- trifluoromethylphenyl) piperazine (TFMPP) and their main metabolites in urine. Journal of Chromatography B, 819, pp. 315–322.
analysis/WDR2011/World_Drug_Report_2011_ebook.pdf [Accessed 20 August 2011]. van Nuijs ALN., et al., 2010. Illicit drug consumption estimations derived from wastewater
analysis: A critical review. Science of the Total Environment, doi:10.1016/j.scitotenv.2010.05.030.
Verenitech, S.S., Lowe, C.J., Mazumder, A., 2006. Determination of acidic drugs and caffeine in municipal wastewaters and receiving waters by gas chromatography-ion trap tandem mass spectrometry. Journal of Chromatography A, 1116, pp193-203.