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

Tropane alkaloids (TAs) are toxic secondary metabolites produced by plants of, inter alia, the genera Datura (thorn apple), Atropa (deadly nightshade) and Hyoscyamus (henbane). 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 EU 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). Visual methods that screen for botanical impurities in unground materials are often used to comply with these regulations. However, visual inspection 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 a 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 could be used, preferably in dipstick format, for application in feed analysis. This study presents the results obtained for the in-house and interlaboratory validation of a dipstick immunoassay for the detection of tropane alkaloids hyoscyamine and scopolamine in animal feed. The target level was set at 800 µg kg-1 for the sum of both alkaloids. The use of a representative set of compound feeds during validation and a robust study design were important requirements to obtain a reliable impression of the relevant characteristics of the assay. The dipstick test displayed similar sensitivity towards the two alkaloids and from the validation studies it could be concluded that the test has a very low probability of producing a false positive result at blank level or a false negative result at target level. The assay can be used for monitoring of TAs in feedstuffs but has also potential as a quick screening tool in food or feed-related poisonings.

MULDER Patrick P J;  VON HOLST Christoph;  NIVARLET Noan;  VAN EGMOND Hans; 

2014-09-18

TAYLOR & FRANCIS LTD

JRC84886

1944-0049,   

http://www.tandfonline.com/doi/abs/10.1080/19440049.2014.914249,    https://publications.jrc.ec.europa.eu/repository/handle/JRC84886,   

10.1080/19440049.2014.914249,