Thin-layer chromatographic detection of ivermectin in cattle dung.

A qualitative method based on thin-layer chromatography (TLC) is described that reliably detects ivermectin as a fluorescent derivative in extracts of cattle dung. The limit of detection (LOD) was < or = 40 ng/g of wet dung. These observations were statistically documented and shown visually using digital imagery. Residues were detected in fresh dung deposited by animals treated 10 days previously with a topical dose (500 microg/kg body weight) of ivermectin.