Field separation‐based speciation analysis of inorganic arsenic in public well water in Hungary

Twenty‐three water samples were collected from public wells from 3 different counties, having a history of high natural arsenic occurrence in Hungary, as well as in the resort area close to the capital city for speciation analysis of arsenic As(III) and As(V). In order to prevent interconversion of arsenic species in the samples, a simple field separation method was applied by using solid phase extraction anion exchange cartridges prior to the inductively coupled plasma sector field mass spectrometric analyses. Total arsenic level in the samples was confirmed to be higher than the health limit value established by the European Union (10 μg × L− 1) for drinking water in 22 samples. Thus, the total As concentration of the samples ranged between 7.2 and 210.3 μg × L− 1. According to the speciation study, two thirds of the samples contained As(V) in more than 60%. Beside the calculation of As(V)/As(III) ratios in the samples, the oxidative character of the geochemical environment could be suggested by determining the concentration of oxyanion‐forming elements (Mo, Se, U, V and W).

► Confirmation of high As concentration in public wells in Hungary by ICP-MS measurements. ► Preservation of As(III) and As(V) ratios by field separation-based method with the use of anion exchange cartridges. ► Two thirds of the samples contained As(V) in more than 60%. ► Population exposed more to As(V) than to As(III). ► As species occurrence in drinking water is affected by complex hydrogeochemical processes, disinfection and contact with air in the water tower.