Speciation of AsIII and AsV in fruit juices by dispersive liquid-liquid microextraction and hydride generation-atomic fluorescence spectrometry

A sensitive method was developed to speciate and quantify As-III and As-V in fruit juices. At pH 3.0, As-III and ammonium pyrrolidine dithiocarbamate (AFDC) formed a complex, which was extracted into CCl4 by dispersive liquid-liquid microextraction (DLLME) and subsequently quantified by hydride generation-atomic fluorescence spectrometry (HG-AFS). After As-V was reduced by thiosulphate at pH 1.7-1.8, total inorganic arsenic (iAs) was determined following the same protocol and As-V was calculated from the difference. Interference from methylarsonic acid (MMA) was managed at <10% by controlling the pH of the reduction reaction. This procedure achieved 1.2 mu g L-1 limit of detection (30) and 92-102% recovery at 10 mu g L-1, and is applicable to most fruit juices except certain pear juice that may contain considerable MMA. Published by Elsevier Ltd.