Abstract:
2,4,6-trinitrotoluene (TNT) in polluted soil sampled in the area of a factory producing
industrial explosives could be determined using an antimony film pre-plated ex-situ onto
a glassy carbon paste electrode (SbF-GCPE) in combination with square-wave cathodic
stripping voltammetry (SWCSV). For electrochemical measurements in Britton-Robinson
buffer (BRB, pH 9), the substance of interest had to be transferred from solid sample
into the solution by extracting with aqueous or water / methanolic media of chosen
composition and adjusted pH, in some cases, followed by neutralising the extracts with
solid NaHCO3. A comparison of the results from analyses of four different solutions has
allowed us to evaluate the most effective extracting agent, which was the case of a
mixture of 0.5 M CH3COOH in 30% CH3OH neutralised with solid NaHCO3, and
further diluted with BRB (pH 9) in order to yield pH ~ 8. In this medium, the SWCSV
analysis with SbF-GCPE has resulted in the content of 3.77 μg TNT in 10 mL extract,
which corresponded to the same contents in mg per 1 kg of dried soil. This has
represented ca. 85% recovery with the result obtained with GC-MS, which can still be
considered as acceptable agreement.
