Rapid determination of trace EDTA in wines and beers by LC-MS/MS

A novel method for quantitative analysis of ethylenediaminotetracetic acid (EDTA) in wines and beers by liquid chromatography coupled to tandem mass spectrometry has been developed. Positive-ion mode was applied as the scan mode, amine species were firstly used as the derivatization reagents of EDTA, and phenylboronic acid was used to react with maltose to eliminate its matrix interference. Primary amines could efficiently eliminate the interference from metal ions (Fe(III) and Cu(II)). The responsive intensity of EDTA with amine derivatization could be improved over 300 times than that without adding amine species. The recovery rate was significantly increased to 104.1% after adding phenylboronic acid at 20.0 mg/L as compared to the control spike-and-recovery experiment results (1.3–1.7%) of beer samples without adding phenylboronic acid. The validated method showed excellent detection sensitivity (0.001 mg/L for LOD (limit of detection) and 0.004 mg/L for LOQ (limit of quantification)) with satisfactory recovery rates (76.0%–97.2%), and good precision (1.40–5.40% RSD values). The optimized method has been satisfactorily applied to the analysis of actual wine and beer samples. It can be proposed as a powerful analytical method of EDTA in wines and beers, and can even be adapted to detect other chelates and polydentate compounds.