Paraquat (or N,N′-dimethyl-4,4′-bipyridinium dichloride) is one of the most widely used herbicides.
The use in agriculture is regulated. A determination in grains, fruit and for instance chiaseeds are important.
Commission Regulation (EU) 2016/1002
(Maximum residue levels for AMTT, diquat, dodine, glufosinate and tritosulfuron in or on certain products)
Regulation (EC) No.396/2005
(Maximum residue levels of pesticides in or on food and feed)