OR/17/011 Summary
| White, D, Williams, P J, Civil, W, and Lapworth, D J. 2017. A field based method for pre-concentration of micro organics using solid phase extraction. British Geological Survey Internal Report, OR/17/011. |
British Geological Survey (BGS) have been researching micro-organic pollutants for many years in the UK (Gooddy et al 2004[1], Stuart et al 2012[2], White et al 2016[3]) and overseas (Sorensen et al 2015[4]). A hindrance to the research, especially overseas, has been the need to transport large volumes of water back to the laboratory and the worry of degradation during transportation prior to LCMS or GCMS analysis. The first step in the LCMS analytical procedure is the solid phase extraction of the micro-organic contaminants onto a small cartridge. This report details the field trial where by BGS, working in conjunction with NLS, carried out the pre-concentration step of sample processing in the field. NLS provided pre-conditioned sorbent Oasis® HLB cartridges supplied in sealed Corning centristar centrifuge tubes. Water samples were run through the cartridges by the field team using a small peristaltic pump prior to sending to NLS for semi-quantative broad screen LCMS analysis. To check the repeatability and the stability of this method the sorbed samples were analysed in duplicate and replicate analysis was carried out over set periods after storage for up to a month. The results from the duplicate replicates are compared to results from the original water sample analysed immediately after sampling. Laboratory and field equipment blanks were included in the trial to check for any contamination introduced by the sampling method and extraction process.
Preliminary results demonstrate that for a large range of compounds, and different types of matrices, this method was able to preserve samples for up to a month. Once the procedure had been validated, it was used to investigate the occurrence of micro-pollutants in a rural groundwater, estuarine waters and a range of surface waters receiving treated sewerage outflows.
The work was funded under the BGS Development Capabilities programme, and was also supported by the BGS Groundwater Science programme under the Groundwater Protection team. Analytical aspects of this work was undertaken in collaboration with Wayne Civil based at Star Cross National Science Laboratory (NLS).
References
- ↑ Gooddy, D, Stuart, M, Lapworth, D, Chilton, P J, Bishop, S, Cachandt, G, Knapp, M, and Pearson, T. 2005. Pesticide pollution of the Triassic Sandstone aquifer of South Yorkshire. Quarterly Journal of Engineering Geology and Hydrogeology, Vol. 38,1, 53–63.
- ↑ Stuart, M E, Lapworth, D J, Crane, E J, and Hart, A. 2012. Review of risk from potential emerging contaminants in UK groundwater. Science of the Total Environment, 416, 1–21.
- ↑ White, D, Lapworth, D J, Stuart, M E, and Williams, P J. 2016 Hydrochemical profiles in urban groundwater systems: new insights into contaminant sources and pathways in the subsurface from legacy and emerging contaminants. Science of the Total Environment, 562. 962–973.
- ↑ Sorensen, J P R, Lapworth, D J, Nkhuwa, D C W, Stuart, M E, Gooddy, D C, Bell, R A, Chirwa, M, Kabika, J, Liemisa, M, Chibesa, M, and Pedley, S. 2015 Emerging contaminants in urban groundwater sources in Africa. Water Research, 72. 51–63. 10.1016/j.watres.2014.08.002