Quantification of hypoglycin A as butyl ester

L-α-amino-methylenecyclopropyl propionic acid (Hypoglycin A, HGA) has been found to be the toxic compound in fruits of the Sapindaceae family causing acute intoxication when ingested as food or feed. Clinical symptoms are consistent with acquired multiple acyl-CoA dehydrogenase deficiency (MADD). Ultra performance liquid chromatography-tandem mass spectrometry was used to measure HGA after butylation. Sample volumes were 10 μL for serum and 20 μL for urine. Internal standard for HGA was d3-leucine, samples were plotted on a 7-point linear calibration curve. Coefficients of variation were <15% at 0.01 μmol HGA/L and ≤4.1% at 10 μmol/L. R2 values for linearity were ≥0.995.In order to quantify non-metabolized HGA together with some of its metabolites plus a spectrum of acyl glycines and acyl carnitines typical for acquired MADD in one single analysis HGA measurement was integrated into a method which we previously developed for metabolites of HGA and acyl conjugates.The new method is suitable for biochemical diagnosis of Ackee fruit poisoning or atypical myopathy in horses and for forensic purposes in cases of suspected HGA poisoning.