Degradation of Chemical Warfare Agent Nitrogen Mustard Using Ferrate (VI)

Abstract

Chemical warfare agents (CWAs) are one of the most toxic compounds. Degradation of CWAs using decontamination agents is one of the few ways to protect human health against the harmful effects of CWAs. A ferrate (VI)-based potential chemical warfare agent decontaminant was studied for the degradation of persistent nitrogen mustard (tris(2-chloroethyl)amine, HN3). By optimizing the reaction conditions, the complete degradation of HN3 was achieved in 4 min. The degradation products contained mostly reduced Fe species, which confirmed the environmental friendliness of the proposed decontamination solution.

Keywords: chemical warfare agent; decontamination; ferrate (VI); nitrogen mustard.

Figure 1

GC-MS analysis of the prepared HN3.

Figure 2

Hydrolysis mechanism of HN3 in water.

Figure 3

GC-FID chromatogram showing the remaining HN3 after 2 min of reactions with ferrate(VI) at different pH levels: 3-SB-2_FID (yellow)—hydrolysis of HN3 at pH 6, 3–2_FID (green)—reaction at pH 3, 4–2_FID (amber)—reaction at pH 4, 5–2_FID (purple)—reaction at pH 5, 6–2_FID (blue)—reaction at pH 6.

Figure 4

Kinetic curves representing time dependence of degradation of HN3 by Fe(VI) under different pH: circles are experimental data where the size of the individual points represents the standard deviations; lines are fitted curves according pseudo-second order kinetic Equation (2); blue colour—pH = 6; red colour—pH = 5; black colour—pH = 3; green colour—pH = 4.

Figure 5

Calculated k₂ rate constants of the degradation of HN3 by iron(VI) at different pH levels.