chinese business visa in hanoi

i am an Irish citizen and want to get a business visa for China in Hanoi. I will be in Vietnam from NOV 9 to NOV 24th and need to go to CN on NOV 29th arriving from Japan.
I won't be back in Ireland to get the visa there as I am travelling around Asia all of November. Is it possible to get this business visa in Hanoi?

I need it as I am conducting an aviation audit on China Southern Airlines in Guangzhou from NOV 29 to DEC 6
I will have a letter of invitation from Southern Airlines
I also have a UK passport if this makes it any easier.