Determination of Arsenic in Fruit Juices Using Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS)

Reports from the US media have raised the attention towards a possible contamination of apple juices by As. The study here described presents the development of an analytical procedure using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for determination of As in apple and orange juices commercialized in the Tetra Pack® package. The microwave-assisted acid digestion of juice was carried out using closed vessels and 2 mol/L HNO3 plus H2O2. These conditions are favorable for a better analytical blank control. Suitable recoveries were reached when promoting reaction with O2 inside the octopole reaction system (ORS3), and the monitoring of 75As16O+ significantly improved the accuracy of the analysis reaching a limit of detection of 0.013 μg/L. Recoveries varied from 88 to 109 % in the MS/MS mass-shift mode. The As concentrations determined in fruit juices ranged from 0.126 to 1.45 μg/L, and they were significantly lower than the maximum tolerable limits imposed by the US and Brazilian legislations. Thus, ICP-MS/MS operated in the reaction mode was an effective instrumental strategy for overcoming spectral interferences, such as 40Ar35Cl+, in As determination as 75As16O+ and allowed the accurate determination of As at trace levels.