Determination of 2,4,6-Trinitrotoluene in Soil Samples Using a Paired EmitterDetector Diode-Based Photometer

This paper reports on developing a low-cost but efficient PEDD-based photometer. The photometer consists of a white LED as the emitter diode, an RGB LED as the detector diode (for the first time), and a multimeter for recoding the signal. The developed PEDD-based photometer was utilized for the determination of 2,4,6-trinitrotoluene (TNT) in soil samples. A Meisenheimer complex of TNT with NaOH in acetonitrile was used as a probe to monitor the presence of residual TNT in soil samples. The calibration curve in the soil sample was linear in the concentration range of 0.86 to 110 mu g g(-1), with a detection limit of 0.27 mu g g(-1) and a quantification limit of 0.81 mu g g(-1). Analysis of the soil samples collected from the Iran Cinema and Television Town using the developed method showed trace residual of TNT.