Isocratic HPLC/UV method for the determination of a synthetic analogue of prostaglandin F2α (PGF2α), used in veterinary medicine as a luteolytic agent for the induction of estrus in cattle, swine and horses, on an ASTRA® C18-HE, 5.0 µm column (150 mm × 4.6 mm, AST-5732-LK46). Proprietary mobile phase, flow rate 0.1 ml/min, 40 °C, UV detection at 220 nm, injection volume 20 µl. The analyte elutes as a single sharp peak at about 29 minutes.