convertion mg/L into mg/Kg

[SabSab]

Hi, I have to compare some results of pesticides amount in an alcoholic beverage obtained by two different laboratories. The first lab expresses their results in mg/Kg and the second lab expresses them in mg/L. How can I convert the results from mg/L into mg/Kg to compare them?
For example 0,009 mg/Kg how many mg/L are there? Many thanks

[gubment_cheez]

To convert mg/kg to mg/L you need to know the density of your solution. If you know the density of the solution in kg/L, then mg/kg ÷ kg/L = mg/L.