## 3 Results and Discussion
### Pesticide Residues in Water Samples
(2012) identified concentrations of various pesticides in surface water samples from Ghana in the range of 0.01-0.04 \(\upmu\)g L\({}^{-1}\) (endosulfan I), 0.01-0.02 \(\upmu\)g L\({}^{-1}\) (4,4-DDT), 0.05-0.15 \(\upmu\)g L\({}^{-1}\) (endrin aldehyde) and 0.11-0.26 \(\upmu\)g L\({}^{-1}\) (endosulfan sulfate) [7]. [PERSON] et al. (2003) identified contamination from the pesticides endo \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Present Study**} & \multicolumn{2}{c}{**[PERSON]-**} & \multirow{2}{*}{**[PERSON] et al., 2014**} & \multirow{2}{*}{**[PERSON] et al., 2013**} & \multirow{2}{*}{**[PERSON]**} \\  & & **[PERSON] et al.,** & & & & **et al., 2003** \\  & & **2012** & & & & \\ \hline \(\upalpha\)-BHC & nd * & - & nd–0.003 & nd–0.003 & nd–0.131 \\ \(\upbeta\)-BHC & nd & - & nd–0.006 & nd–0.009 & nd–0.096 \\ \(\upgamma\)-BHC & nd–0.023 & 0.02–0.08 & nd–0.003 & nd–0.003 & nd–0.081 \\ \(\updelta\)-BHC & nd & 0.01–0.12 & nd–0.010 & - & nd–0.189 \\ Heptachlor & nd–0.108 & 0.02–0.04 & nd–0.012 & nd–0.001 & nd–0.020 \\ Aldrin & nd–0.014 & 0.01–0.02 & - & nd–0.001 & nd–0.101 \\ \(\upgamma\)-Chlordane & nd & 0.01–0.12 & - & nd–0.002 & - \\ \(\upalpha\)-Chlordane & nd & - & - & nd–0.001 & - \\ Endosulfan I & nd–0.005 & 0.01–0.04 & nd–0.010 & nd–0.004 & nd–0.020 \\ \(4,4^{\prime}\)-DDE & nd–0.020 & nd & nd–0.005 & nd–0.001 & nd–0.064 \\ Dieldrin & nd–0.013 & nd & - & nd–0.002 & nd–0.039 \\ Endrin & nd & 0.01–0.03 & - & nd–0.004 & nd \\ Endosulfan II & nd & - & nd–0.013 & - & nd–0.022 \\ \(4,4^{\prime}\)-DDD & nd & - & nd–0.005 & nd–0.001 & nd \\ Endrin aldehyde & 0.030 & 0.05–0.15 & - & - & nd–0.080 \\ Endrin ketone & nd & nd & - & - & nd–0.080 \\ \(4,4^{\prime}\)-DDT & nd & 0.01–0.02 & nd–0.014 & nd–0.010 & nd–0.035 \\ Endosulfan sulfate & 0.009 & 0.11–0.26 & - & - & nd–0.058 \\ Methoxychlor & nd & nd & - & nd–0.018 & nd \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of pesticide contamination concentrations (\(\upmu\)g L\({}^{-1}\)) with the reported data. sulfan I, 4,4\({}^{\prime}\)-DDE, endrin aldehyde, 4,4\({}^{\prime}\)-DDT and endosulfan sulfate in the surface water samples of Northern Greece, with maximum concentrations of 0.020, 0.064, 0.080, 0.035 and 0.058 \(\mu\) L\({}^{-1}\), respectively [19]. However, [PERSON] et al. (2013) reported pesticide contamination from endosulfan I, 4,4-DDE, 4-DDD, 4,4-DDT and methoxychlor in the surface water samples of Lake Chaohu, China with maximum concentrations of 0.004, 0.001, 0.001, 0.010 and 0.018 \(\mu\)g L\({}^{-1}\), respectively [8]. [PERSON] et al. (2014) also reported organochlorine pesticide contamination in the surface water samples of China with maximum concentration of 0.010, 0.005, 0.013 and 0.014 \(\mu\)g L\({}^{-1}\) for endosulfan I, 4, 4-DDE, endosulfan II and 4,4-DDT, respectively [46]. All these studies show that pesticide contamination is a serious threat to human health and the environment. Therefore, efficient analytical and extraction methods are necessary to determine pesticide contamination in environmental samples. The analytical parameters studied with the SPME-GC-ECD method showed good percent recoveries, low detection limits and acceptable linear correlation, making them suitable for application in the analysis of water samples using the solid-phase micro-extraction (SPME) technique. This method allows a significant decrease in the volume of sample extracted, organic solvent consumption, and sample handling time in comparison with classical liquid-liquid extraction (LLE), or solid phase extraction (SPE) that has been commonly used in the analysis of pesticides in waters.