Recent developments in humic acid characterisation by CE andMALDI-TOF mass spectrometry

Humic acids (HAs) of different origin (IHSS standards) were studied using cappilary zone electrophoresis (CZE) and matrix assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF MS). It was found by CZE and MS that HAs are mixtures of the same and/or similar compounds. Mass spectra of humic compounds were found to be analogous for all humic acids studied, but some differences were observed, as well.