degradation of OPEs in water-isopropanol (50:50) extracts of swabs used for sample collection from different surfaces .It was shown that such mixture provides the best extraction of various types of inorganic and organic explosives [20]. However, as a result of elevated viscosity of this mixture the FIA system in this study need to operate at pressures higher than those normally provided by peristaltic pumps .Also, initial experiments using peristaltic pumps demonstrated poor stability of the silicone tubing when in contact with solutions of isopropanol, hydrochloric acid and sodium hydroxide requiring the frequent replacement of the tubing and leading to poor reproducibility of data. For this reason a pneumatic FIA-CL system consisting of five pressure lines equipped with precision low pressure regulators(maximum operating pressure0.2MPa) was constructed as shown in Fig. 1.