A poison expert killed himself by taking cyanide in front of his fiancee, an inquest has heard.
Dr Manning lectured in toxicology at Liverpool John Moores University
Dr Francis Manning, 41, a lecturer at Liverpool John Moores University, died within minutes of swallowing the chemical at his Merseyside home.
Wirral Coroner's Court heard Dr Manning, who taught toxicology and biochemistry, suffered depression.
Coroner Christopher Johnson recorded a verdict of suicide. He said Dr Manning was aware of the cyanide's effect.
The inquest heard that Dr Manning was also having problems in his relationship with his fiancee, Sara Routledge.
She had gone back to the flat they shared in West Kirkby on 1 October after receiving a text message from her partner saying "help".
When she got there he was sitting on the sofa.
As she telephoned a friend, to tell him there was no emergency, she saw Dr Manning go into the bedroom and swallow a white substance.
She heard him crunching the substance in his teeth before he began gasping for breath, choking and slumped against a wall.
Ms Routledge called an ambulance and gave him mouth-to-mouth resuscitation but Dr Manning, a divorced father of two, was declared dead on arrival at hospital.
Wirral Coroner Christopher Johnson ordered that no post-mortem examination be carried out because of the potential risk to hospital staff.
The plastic tube was examined and found to contain a cyanide salt compound. It was unclear where Dr Manning got the chemical.
The court heard that Dr Manning had previously drunk methanol from his workplace, during a bout of depression in the mid 1990s.
Mr Johnson said: "The deceased's profession would, in my opinion, have made him completely aware of the outcome of the actions that he took.
"They would be capable of no misinterpretation."