Search for "extractants" in Full Text gives 3 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2018, 14, 3106–3111, doi:10.3762/bjoc.14.290
Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32
Beilstein J. Org. Chem. 2009, 5, No. 59, doi:10.3762/bjoc.5.59