Glyphosate is an aminophosphonic analogue of the natural amino acid glycine and, like all amino acids, exists in different ionic states depending on pH. Both the phosphonic acid and carboxylic acid moieties can be ionized and the amine group can be protonated and the substance exists as a series of zwitterions. Glyphosate is soluble in water to 12 g/L at room temperature.
As mentioned, it dissolves in water.
I have two suggestions for you to read the articles related to this material and your work topic, usually information is given in the materials and methods section.
My second suggestion is to use solvents that have a similar structure.
Have you tried methanol, ethanol, acetic acid, propanol and butanol?