You will need the density of the solution.

Determine the density of sample solution once you got value, you have to multiply with final results to get results in mg/Kg

ug/ml and mg/kg mean the same thing. That is, you can use your results directly in mg/kg.

Hi Mihaela Cudalbeanu ,

if you report the result as mass of pesticide / mass of sample, you must consider that your extract (VOLUME) derives from your sample (MASS).

If you did dilution etc, you have to consider every operation that can change the proportion between extract (VOLUME) and sample (MASS).

It's the same thing as long as we are you are dealing with a very dilute solution in water or mobile phase. See the equation below;

mg/Kg = 1000*ug/ 1.0*L of water (since 1 L of water weighs 1 Kg)

Thank you all for your answers

Hi Mihaela

It depends of your procedure, conc in mg/kg=conc in ug/ml*(v/w)

V stand for the volume of organic solvent and w for the weigh of your matrix for pestice extraction