Determination of nitroaromatic, nitramine, and nitrate ester explosives in soils using GC-ECD

Abstract : Nitroaromatic, nitramine, and nitrate ester explosives are analytes of interest for hazardous waste site characterization and land mine detection. Traditionally determined by high-performance liquid chromatography (HPLC), these thermally labile analytes may be determined by gas chromatography (GC) by using direct injection into a deactivated liner and a short (6-m) wide-bore capillary column. Gas chromatography-electron capture detector (GC-ECD) and HPLC-ultraviolet (UV) concentration estimates of these compounds in field-contaminated soils from hazardous waste sites were compared, and excellent correlation (r > 0.97) was found between the two methods of analysis for the compounds most frequently detected: 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT), 1,3-dinitrobenzene (1,3-DNB), 1,3,5-trinitrobenzene (TNB), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). GC-ECD method detection limits (MDL) were about 1 micrograms/kg for the di- and trinitroaromatics, about 10 micrograms/kg for the mononitroaromatics, 3 micrograms/kg for RDX, 25 micrograms/kg for HMX, and between 10 and 40 micrograms/kg for the nitrate esters (NG and PETN).