It all began when several people attending a festival in Wakayama-Ken, a local district in western Japan, died after eating food laced with arsenic. Other such poisonings involved green tea tainted with sodium azide in Niigata-Ken and Oolong tea dosed with cyanide in Nagano-Ken. In each of these incidents, the victims didn't receive appropriate treatment as quickly as they might have if the toxins had been identified quickly and efficiently.

The Goal: Database of Illicit Drugs
Not the least factor in the NPA's selection of HP gas chromatographs was the feature of retention time locking (RTL). This feature allows retention times to be reproduced within hundredths of a minute, regardless of location, equipment configuration, or the operator's technique. No matter which of the 51 local district laboratories will receive a given sample, the GC results will be the same. In conjunction with the NPA's own software, RTL will also eventually yield a database of illegal drugs that not only identifies the substance, but pinpoints its origin as well.

As for speed, the HP CE systems will complement the GCs for the rapid screening for four toxic anions and other compounds. Their ion separation power is essential, because conventional poisons (see figure) exist in food and beverages as ions. Since aqueous samples require no preparation, police technicians may be able to analyze a given sample in as little as 15 minutes before going on to more elaborate analytical processes.

The Advantages of CE in Forensics
Director Noriko Tsunoda of the Identification Center of the National Police's Research Institute commented on the new application of CE technology for forensic chemistry. "Because of its high separation power and high chemical information content, GC/MS is the most widely used technique for the analysis of trace poison in complex matrices. For the analysis of thermolabile, nonvolatile and less volatile compounds, on the other hand, HPLC, LC/MS, IC (ion chromatography), and CE are the methods of choice."

Director Tsunoda goes on to point out the drawbacks of HPLC in police work: long run times, often insufficient resolution, and a short column life caused by heavy matrices—the latter problematic in IC as well. "This is where CE offers distinct advantages in the trace analysis of toxins," says Director Tsunoda.