26 May / June 2014
which has resulted in run-off into local aquatic ecosystems [8,9]. This can have a dramatic effect on this particular ecosystem and thus, monitoring of the water around these sites will help to ensure that the over usage of agrochemicals does not occur. It is often the case that these chemicals are used too widely throughout the year with little benefit to the crop. Careful management of the use of the agrochemicals will ensure that both a minimal effect on the environment as well as ensuring an effective crop protection regime is employed.
Figure 2. Diagram of single valve system using two pumps, reprinted with kind permission from ref 10.
It is, therefore, necessary to develop analytical technologies which can identify and quantify a wide range of aquatic pollutants and as this will allow the determination of the environmental fate of these contaminants, and thus reduce pollution and aid the usage of agrochemicals. A comprehensive assessment of the aquatic fate and effects of organic micropollutants is greatly hindered by the need to develop compound- specific methodologies prior to sampling and analysis. A data-driven workflow will be presented, which couples high-resolution, accurate-mass mass spectrometry and highly sensitive online solid phase extraction (SPE) coupled to liquid chromatography analysis, ensuring complete characterisation of organic pollutants in aquatic environments.
Figure 3. Representative TIC from non-targeted screening of SPE extracts from Pond 5 sample (left) and wastewater composite sample (right)
Table 2. Compounds identified by non-targeted screening
Compound Atraton Atrazine
Atrazine-2-hydroxy Carbamazepine Carbendazim DEET
Fluridone
Hydrocortisone Mefluidide Metolcarb Metoprolol Promecarb Propanolol Pyroquilon
Sulfamethoxazole Temazepam Trimethoprim
Sample(s) Ponds 25, 43
Ponds 5, 25, 43, WWTP, WW Comp. Pond 25
WWTP, WW Comp. WWTP
Ponds 5, 25, 43, WWTP, WW Comp. Ponds 25, 43
WWTP, WW. Comp. Ponds 5, 25 WWTP
WWTP, WW Comp. WW Comp.
WWTP, WW Comp.
Ponds 5, 25, WWTP, WW Comp. WW Comp. WW Comp.
WWTP, WW Comp.
WWTP = Wastewater treatment plant lagoon WW Comp = Wastewater composite
In this work, water samples were collected from a coastal golf course community and screened for the presence of trace organic contaminants by initially using a non-targeted HPLC-HRMS workflow. The occurrence of identified and confirmed contaminants was then quantitatively assessed by a more targeted high-throughput online SPE LC/ MS method. The coupling of SPE with LC allows for a greater robustness of the assay and also allows for sample pre-concentra- tion which will allow for the improvements in the sensitivity of the assay. This will aid the development of mathematical models to describe the fate of micropollutants within an aquatic environment.
Experimental Sample Collection
Surface water, groundwater, and wastewater effluent samples were collected from Kiawah Island, SC (Figure 1), a coastal golf course community where turf-grass management chemicals are extensively applied and reclaimed wastewater is used for irrigation. Golf course and storm water runoff was collected in ponds, which are connected in series and communicate tidally with a neighbouring estuary.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48
