INTRODUCTION Determination of residual explosive materials and their degradation products in the environment has drawn increased attention due to their toxicity, persistence, and increased demand for forensic analysis concerning national security.Gas chromatography has traditionally been used to detect and quantify explosive compounds; however, because some are thermally unstable or nonvolatile, using this method can result in inexact determinations. HPLC with UV detection, however, is ideally suited for low-level determination because it is not subject to these limitations. U.S. EPA Method 8330 describes an HPLC method with UV detection for determination of 14 priority explosives and related substances(Figure 1). The method recommends the use of a C18 reversed-phase column as the primary column for separation, and a secondary column for confrmation. Acclaim® Explosives E1 and E2 columns can provide baseline resolution for 14 compounds with complementary selectivity under identical chromatographic conditions (except mobile phase composition) while reducing analysis time.These columns were used with EPA Method 8330 and the results are reported in this Application Note.