ONE of the puzzles at the Kim Jong-nam murder trial is how the accused managed to kill the North Korean with VX nerve agent without harming themselves or passers-by.

Chemists following the trial this week said the women might have used a “combined method” to synthesise elements of VX without heat into a “deadly nerve agent”, reports The Wall Street Journal.

An alkyl chloride identified by a Chemistry Department expert was found on Kim’s clothing and one of the accused, Vietnamese Doan Thi Huong.

The “nerve agent precursor” that chemical weapons and analysis head Dr Raja Subramaniam identified can be combined with another to form VX, the experts told WSJ.

The chemical experts also told the American business daily that there was likely another precursor – a sulphur-containing organophosphate – that went undetected in laboratory tests.

They said the sulphur-containing organophosphate came from a group of compounds commonly used in insecticides.

Applied together to Kim’s face, they would have formed VX and entered his bloodstream in minutes, WSJ said.

The sulphur-containing organophosphate can degrade quickly, especially in humid environments, leaving only a rotten-egg smell and an acid, traces of which were found on the other accused, Indonesian Siti Aisyah’s sleeveless shirt, Raja told the court on Friday.

The women smeared Kim’s face with VX at the Kuala Lumpur International Airport 2 on the morning of February 13. He was pronounced dead at Putrajaya Hospital upon arrival, about an hour after the face-wiping incident.

VX works by blocking the enzyme cholinesterase, leading to loss of control of muscles and glands.

A Kuala Lumpur Hospital pathologist, Dr Norashikin Othman told the court on Tuesday, that Kim’s cholinesterase level was low, consistent with poisoning from nerve agents and insecticides.

“Kim’s cholinesterase level was 344 and that is low… meanwhile, the reading of the enzyme in the samples taken from Siti Aisyah and Doan was normal,” she said in reply to the prosecutor.

She earlier told the court that the cholinesterase level in a normal man would be between 5,320 and 12,290.

She also concurred with prosecutor Wan Shaharuddin Wan Ladin that the VX nerve agent can affect the heart and lung muscle as well as the glands controlling the saliva and mucus. – October 7, 2017.