Use of chlorinated solvent like DCM is under scanner today. It will be better if you can use ethyl acetate as extracting solvent.

They use the reference below:

Hirotaka Obana ,* Masahiro Okihashi , Kazuhiko Akutsu , Yoko Kitagawa , and Shinjiro Hori

Osaka Prefectural Institute of Public Health, 1-3-69, Nakamichi, Higashinari, Osaka, 5370025, Japan

J. Agric. Food Chem., 2003, 51 (9), pp 2501–2505

DOI: 10.1021/jf0261102

Publication Date (Web): March 22, 2003

If you do not have access for full paper... jus ask through researchgate :-)

INTERESTING paper as well:

Thank you. But the document sent by Victor Casana-Giner can not be viewed. May it possible to send in any other format.

Please try http://www.researchgate.net/profile/Uros_Petrovic/publication/258828264_Determination_of_toxicity_of_neonicotinoids_on_the_genome_level_using_chemogenomics_in_yeast/file/9c96052a9de8f91825.pdf

Article Determination of toxicity of neonicotinoids on the genome le...