| The fate and phytophotolysis of RDX in reed canary grass (Phalaris arundinacea) was studied. A preparation technique for analysis of RDX and other explosives in plant tissues was developed and tested with 14 explosives-related compounds. Method detection limits for HPLC analysis were calculated. The extraction efficiency for RDX after plant uptake, determined using 14C-RDX, exceeded 50%.; RDX was taken up and translocated to the leaves of reed canary grass. Combustion analysis after 14C-RDX uptake showed that 60.9%–68.2% of the 14C applied was recoverable, mostly from the leaves. The remaining fraction was lost, presumably due to volatile product formation. Of the 14C remaining in the plant, approximately 52% was recoverable as 14C-RDX. Less than 2% of the applied 14C-RDX was recovered as volatile formaldehyde in closed uptake experiments.; Photolysis of RDX in DI water produced nitrous oxide (72.2%), nitrite (11.1%) and an unknown compound, presumably N-methyl-N,N-dinitrosomethanediamine. 15N-ring labeled RDX data showed the nitrous oxide contained one ring nitrogen atom and one nitro-group nitrogen atom giving evidence for RDX ring cleavage. Nitrosyl radical was detected, but hydroxyl radical was not detected in solution.; Photolysis of 12C-RDX, 13C-RDX and 15N-ring labeled RDX in DI water showed that a major product contained two carbon atoms and two ring nitrogen atoms from the parent RDX. N-methyl-N,N-dinitrosomethanediamine was proposed as the chemical structure based on LC/MS analysis. A 14C-RDX experiment showed formaldehyde to be a major photodegradation product.; Photolysis of RDX in reed canary grass leaves was evidenced by the production of nitrous oxide (74.6%) from excised leaves containing RDX. Evidence of N-methyl-N,N-dinitrosomethanediamine in reed canary grass was obtained using stable isotope labeled RDX and LC/MS analysis. It was hypothesized that formaldehyde produced from photolysis of RDX in reed canary grass was conjugated into the plant tissue via a glutathione-dependent formaldehyde dehydrogenase enzyme. |
