Flow injection liquid-liquid microextraction of CL-15 explosive and its fluorimetry determination in water samples

Abstract

CL-15 or 1,4,5,8-tetranitro-1,4,5,8,tetraazadifurazano-[3,4-c][3,4-H] decalin, is a high energetic explosive. This investigation showed that this compound due to the elimination of an H⁺ from its structure converts to have a sensitive and unique fluorophore center which changes color as pH changes. This behavior introduces a rapid and simple way for its detection. In the present study, a flow injection liquid-liquid microextraction method was developed to preconcentrate and determine by fluorimetry CL-15 explosive. After optimization of the main parameters affecting the FI-LLME process efficiency, the proposed method had a linear range of 0.28–12.06 μg mL⁻¹ with R² = 0.9987, LOD = 0.066 μg mL⁻¹, E_f = 27.8 and %RSD = 5.12%; while optical conditions were: Ex 380 nm, Em 480 nm, medium sensitivity. Other operational conditions such as time of separation, separation coil diameter and organic solvent volume were 1 min, 3 m and 150 μL, respectively. In comparison with conventional analysis methods, this method provides some advantages such as rapidity, cleanliness, and uses only a small volume of organic solvent. Finally, the performance of the method for efficient extraction of analyte from real aqueous samples in the presence of some similar explosives was investigated.