Determination of arsenic in water samples treated with ozone

The applicability of ozone as a digesting agent in the trace analysis of arsenic in natural water samples has been investigated. Differential pulse polarographic (DPP) and spectrophotometric (SP) methods were applied for the determination of arsenic in ozone and, as reference, in persulphate treated samples. Additionally, inductively coupled plasma mass spectrometry (ICP-MS) was used for the total arsenic determinations. No significant differences were found between the results of the measurements using different techniques in the investigated natural ground water samples. Similar detection limits of 5 microg/L, lower quantification limits of approximately 10 microg/L and linearity limit up to 300 microg/L were estimated for the both DPP and SP measurements. Thus, ozone treatment may, in many cases, be successfully used for the pretreatment of samples prior to both DPP and SP determination of arsenic in natural water samples.