Gas Chromatograph with Pulsed Discharged Detector for Explosives Covered with Petroleum and Tear Gas as Evidence

Abstract

A gas chromatograph-pulsed discharged detector can be used in three modes, such as a pulsed discharged helium ionization detector (PDHID), a pulsed discharged photo ionization detector (PDPID) and a pulsed discharged electron capture detector (PDECD). In this report, this detector's performance was compared with other detectors, such as GC/MS, GC/AED and GC/ECD. The PDHID and/or PDECD mode of this detector was applied to the detection of explosives-covered petroleum, and tear-gas spray using 2-chloroacetophenone, respectively. For the detection of explosives, simulated experiments prepared with 1 vol%, 0.01 vol% and 0.001 vol% nitroglycerin were added to kerosene. Also, for the detection of tear gas, 100 ppt, 10 ppt and 1 ppt of 2-chloroacetophenone gas as simulated sample were used. In the nitroglycerin/kerosene sample, the detection limits by GC/AED and GC/MS were 1 vol%, but by GC/ECD and GC/PDECD, 0.001 vol% of nitroglycerin was detected without any interference by kerosene. In 2-chloroacetophenone as a tear-gas sample, 0.01 ppt of 2-chloroacetophenone could be detected by GC/ECD and GC/PDECD; this detection limit was 10000-times lower than that of GC/MS. Furthermore, nitrogen and oxygen were also detected by PDHID. By this examination, GC/PDD was considered to be among the useful analytical devices in forensic investigations.