The behaviour of a number of pesticides and related compounds has been studied by thin-layer chromatography (TLC) on Florisil in five different solvents. As Florisil is used as a cleanup prior to final analysis of pesticide residues, an attempt has been made to relate the behaviour of these compounds on Plorisil TLC to their elution volume on a Florisil column. From the XJP values obtained by TLC it could be seen which solvents would be required to elute the compounds from a Florisil column.
(IS 35, V/V), toluene and acetone-toluene (I : g, v/v). Laboratory reagent grade solvents were used in each case:
Pesticides. Many compounds were used in the pure state; others were technical grade material. In these cases the largest spot formed was taken as the compound of interest. In the case of chlordane a number of spots was recorded.
Tlzi&ayer ckronaatogra$l~y adsorbent. Florisil TLC (Floridin Co., 2 Gateway Centre, Pittsburgh 22, Pa., U,S.A,).
Colti~z~z clzromatogra$hy adsorbegzt. Florisil 60-80 mesh, 660" factory treated (Floridin Co., 2 Gateway Centre, Pittsburgh 22, Pa., U.S.A.).
Ckromoge&c reagents, (I) Silver nitrate reagent prepared according to M~TCWELL~.
(2) 4-(p-Nitrobenzyl)-pyridine reagent according to WATT@. (3) Iodine vapour.
Tlziwlayer chromatography.