The determination of iron as its EDTA complex in Helix aspera by hydrophilic interaction liquid chromatography coupled to Fourier transform electrospray ionisation mass spectrometry

Metal complexes of Fe(III) such as Fe(III) ethylene diamine tetraacetic acid (FeETDA) have been observed to be effective molluscicides. The mechanism of toxicity of FeEDTA complex on molluscs is not clear and it is also not known if Fe(III) in the form FeEDTA is absorbed more effectively by snails than simple iron salts. Snails were fed with molluscicide pellets containing the FeEDTA complex and also with pellets containing FePO4 after 3-4 days the hearts, kidneys and dart sacs removed and analysed for Fe(III) content. Hydrophilic interaction liquid chromatography (HILIC) coupled with Fourier transform electrospray ionisation mass spectrometry (FT-ESIMS) was used to analyse the sample extracts. The method had a very wide linear range from 2 to 10,000 ng mL−1, intra- and inter-day precisions of ca. ±0.5% were observed for the analysis of extracts from snail tissues spiked with Fe(III). The limit of detection was of 0.5 ng mL−1 for a 20 μL injection. The levels of Fe(III) in tissues from snails fed Fe EDTA pellets were 10-100 times higher than the levels in snails fed FePO4 pellets. The analysis of Cu, Zn, Ca and Mn could also be carried out using the same analytical procedure.