Russia has now blocked 8 UN resolutions on Syria. Ya think there is a pattern there? 
Did you read the UN resolution?
It wanted to let the Organization for the Prohibition of nuclear weapons do the investigation.
For your education, here are its member states:
www.opcw.org/about-opcw/member-states/
This is about as independent as it gets, but you are trying to spread fake news in an effort to make Russia and Assad the victims.