Dear Sir. Concerning your issue about the suitable method for extraction and detection of pesticide from washed water of vegetables. Various washing protocols have been assessed for efficacy using Agilent LC/MS and GC/MS instrumentation to measure pesticide residues in tomatoes and other produce. Washing procedures in water and various solutions, with and without sonication, were evaluated in the laboratory. In general, the effect of sonication depended on the washing treatment and on the pesticide. A separate experiment measured pesticide residues in contaminated samples before and after being washed in a pilot plant flume, which resulted in reductions of 40 to 90% after one minute in water at room temperature. I think the following below links ay help you in your analysis:

http://cn.agilent.com/cs/library/applications/5991-3879EN.pdf

http://www.academicjournals.org/journal/JECE/article-full-text-pdf/C2F186F4264/

http://www.pesticideresearch.com/site/docs/PcideInstructor.pdf

https://www.epa.gov/sites/production/files/2015-10/documents/method_1699_2007.pdf

Thanks

There are many different pesticides with different properties. So first determine which pesticides are the important ones to look at and then determine which solvent or solvents are most appropriate to extract them from a watery solutions.

i try poultry feed but liquid chromatography but i got 20% recovery i kept i hold

i don't have Hplc Lc-ms-ms or Gc-ms 

But in wash water of vegetables we don't konw which pesticides were exactly used? Then how to determine ?

It should not be to difficult to make a list of pesticides that are allowed to be used on the vegetables in the producing country or countries.

It will be harder to get an idea of the pesticides that might be used illegally.

The major pesticides really used in growing vegetables should also be relatively easy listed.

The scientific challenge will be to select those pesticides with a high toxic potential and rather well soluble in water (most pesticides are quite soluble in oil and not in water).

Furthermore the concentrations to be detected in this surplus of rinsing water will be quite low, so a quite sensitive and selective analytical method has to be used or developed.

i try this first take sample with 100% acetonitrile and shake thoroughly then filler the solvent then evaporate the solvent in rotor  evaporator  reconstitute same solvent

inject to lc-ms-ms