| چکیده انگلیسی مقاله |
2,4,6-trinitrotoluene (TNT) is relatively water soluble compound which can be found in soil and groundwater around places associated with the manufacturing, handling, testing, and disposal of explosive and propellant materials [1, 2]. In the presence of acetone and a base, TNT can form the red-colored Janovsky complexes to produce 2,4,6-trinitrobenzyl anion (TNT-) which can easily monitored in the visible spectrum [3]. Therefore, a rapid flow injection (FI) spectrophotometric method as an effective method involving automation, miniaturization, versatility, greater accuracy, higher speed, lower sample and reagent consumption (few tenths of microliters), lower risk of contamination or analyte loss and inexpensiveness have been attracted great attention, especially in forensic science [3, 5]. This method is developed for the selective determination of TNT in soil samples. The method was based on a derivatization reaction of TNT with sodium sulfite in a basic acetone medium through Janovsky reaction. Besides the many advantages of spectrophotometric technique, some analytes may be hard to measure due to overlapping their bands [4]. Due to the high amount of data obtained and the need of evaluate and interpret these data, chemometrics method using partial least square regression (PLSR) was utilized. PLSR is the one of the multivariate calibration methods that is performed by decomposition of concentration and absorbance matrices in order to identify the unknown variables of the model [6, 7]. Finally, an acetone-water medium of 80% (v/v) acetone was found to be optimal condition for the determination of TNT. The dynamic linear range and limit of detection were 5-100 µg g-1 and 1 µg g-1 for 200 mg soil samples. Quantitative results from the determination of TNT in contaminated soil samples showed the good recoveries in the range of 94.6-106.3%. |
