Hi, I am looking to test the effectiveness of pesticide residues extraction from the soil sample using the Dutch mini luke extraction method. The extraction method would involve the mixing of three different solvents; 20 mL of acetone, 20 mL of petroleum ether, and 10 mL of dichloromethane.
As I am currently carrying out the method validation of this method, I would need to calculate the spiking concentrations to get exactly the concentration that I am aiming for. For me to do it correctly, I presume I would need to know which solvent (acetone/petroleum ether/dichloromethane) would be the top layer, hence the layer that has all the extracted pesticides.
My question is, with the mixing of three solvents, which solvent would be the top layer? Thank you.
Dear scientist,
Petroleum ether is the top layer because of density.
due to the density diffrences of acetone/petroleum ether/dichloromethane petroleum ether placed on top layer
difficult to separate a solvent mixture, the best thing is to evaporate the solvent mix and resume everything with dichloromethane or solvent used for GC analysis
excuse my english
They are all miscible; there won't be a "top layer". Mixing the solvents is not how the mini-Luke method works; it involves extraction into a water-soluble solvent (acetone) and then back-extraction into a water-immiscible solvent (pet ether). Partition coefficients, and your ability to manipulate them, play a large part in your success or failure with this method; this is one reason why almost all food scientists have moved to QuEChERS.
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