Optimization of accelerated solvent extraction for the analysis of munitions residues in sediment samples

Accelerated solvent extraction (ASE) has been compared with a Soxhlet extra ction for extracting and estimating the concentration of hexahydro-1,3,5-tr initro-s-triazine (RDX) and octahydro-1.3,5,7-tetrazocine (HMX) in sediment samples. Extraction of RDX and HMX was studied in terms of process kinetic s and recovery. A three factor, 16 run triplicate experimental design was u sed to generate data on each of two extraction solvents, acetonitrile and a mixture of acetone-methanol (1:1). Response surface methods were used to m odel the dependence of the concentration on the experimental conditions and to establish the optimum extraction conditions. The results were complex i n that several interactions were found among analyte, method, and solvent. Acetonitrile was superior to acetone-methanol for RDX and HMX from the pers pectives of kinetics and recovery, due in part to a much higher solubility. The accelerated solvent extraction generally recovered more than the Soxhl et. In terms of sample throughput, the accelerated solvent extraction offer s advantages over the Soxhlet. A spike recovery study using fortified sedim ent yielded complete recoveries of HMX and RDX. (C) 2001 John Wiley & Sons. Inc.