Intra- and inter-laboratory validation of a dipstick immunoassay for the detection of tropane alkaloids hyoscyamine and scopolamine in animal feed

The most relevant TAs are (–)-L-hyoscyamine and (–)-L-scopolamine, which act as antagonists of acetylcholine muscarinic receptors and can induce a variety of distinct toxic syndromes in mammals (anti-cholinergic poisoning). The European Union has regulated the presence of seeds of Datura sp. in animal feeds, specifying that the content should not exceed 1000 mg kg –1 (Directive 2002/32/EC).

For materials that have not been ground, visual screening methods are often used to comply with these regulations, but these cannot be used for ground materials and compound feeds. Immunological assays, preferably in dipstick format, can be a simple and cost-effective approach to monitor feedstuffs in an HACCP setting in control laboratories. So far no reports have been published on immunoassays that are capable of detecting both hyoscyamine and scopolamine with equal sensitivity and that can be used, preferably in dipstick format, for application as a fast screening tool in feed analysis.