PETALING JAYA: The chemical that killed Kim Jong-nam is likely to be a new chemical and not easily detected, said a top toxicologist.
He said the chemical that could kill quickly after being sprayed on the face could be a cyanide-based or chlorine-based gas dissolved in solvent.
In a political assassination, the perpetrators are not likely to use these because they may have more effective toxic chemicals.
If poison is sprayed on the face, it could be in vapour form, and the chemical could kill more rapidly, said the toxicologist who did not want to be named.
In cyanide poisoning cases, the colour of the skin would darken as a result of blockage of respiratory function and forensic pathologists would be able to tell quite easily, he said.
He said the chemicals could be in a canister, ampoule or aerosol container.
If contained in an ampoule, the killer would open the ampoule in the handkerchief and force it into the victim's nose.
"But, I don't think the perpetrators will use common chemicals because they may have better and more effective chemicals which are produced specifically for this purpose.
"I suspect it may be a new chemical.
"They can also mix a lot of chemicals together and it is difficult to pinpoint.
"We cannot speculate because the chance of getting it right is one in a million," he said.
He said he would not know the possibilities unless the samples are sent to him for him to analyse.
On Thursday, the Chemistry Department received several samples for analysis from the police over their investigation into the killing of Jong-nam.
Besides the Chemistry Department, the toxicology laboratory in the Faculty of Medicine in Universiti Malaya is also capable of testing chemicals even in trace amounts, he said.
A chemist who declined to be named said that if the chemical that was being analysed is a common one, it would usually take a few days but if it was not one that could be tested by available methods here, it might take longer.
Meanwhile, the Gate B free access into the Chemistry Department here is now closed after sample materials of the alleged assassinated Jong-nam were sent there.
The security guards said reporters were not allowed entry.
"The police have ordered us to close the gate," said one of the two guards there.