Selective gas-phase capture of explosives on metal beta-diketonate polymers.
A variety of metal beta-diketonate polymers were assessed for gas-phase selective retention of nitro aromatic, nitrate ester, and peroxide explosives. The La(III) complex of p-di(4,4,5,5,6,6,6-heptafluoro-1,3-hexanedionyl)benzene [La(dihed)] showed 13-42 times the retention for the nitro aromatic compounds compared to a control column (identical column but lacking the 5% loading of the metal beta-diketonate polymer). Nitrate esters, the peroxide explosive triacetone triperoxide, and the taggant 1,4-dimethyl-1,4-dinitrobutane were too strongly retained to elute from the La(dihed) column; however, these compounds could be eluted from the less retentive Cu(dihed) or Zn(dihed) columns. A Kováts index of 2124 for 2,4,6-trinitrotoluene (TNT) on the La(dihed) column compared to 1662 on the control illustrates the excellent discrimination against nonpolar hydrocarbons, the principal matrix interference expected in air samples. A proof-of-principle experiment demonstrated analysis of an extrapolated 47 part-per-trillion (ppt) (v/v) of TNT in an air extract concentrate.
Harvey
Scott D
SD
Pacific Northwest National Laboratory, Richland, WA 99352, USA. scott.harvey@pnl.gov
Wenzel
Thomas J
TJ
D000388:Air / Q000032:analysis; D002849:Chromatography, Gas; D053834:Explosive Agents / Q000032:analysis*; D007202:Indicators and Reagents; D007811:Lanthanum / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D014303:Trinitrotoluene / Q000032:analysis
D053834:Explosive Agents; D007202:Indicators and Reagents; D008670:Metals; D009942:Organometallic Compounds; D011108:Polymers; D014303:Trinitrotoluene; D007811:Lanthanum