The molecular resonance fluorescence method for determination of arsenic in hair samples

A molecular resonance fluorescence quenching method for the determination of arsenic was proposed. The method is based on the quenching effect of As (V) on the molecular resonance fluorescence of Rhodamine B (RhB) in sulfuric acid medium and in the presence of molybdate and PVA. The influences of acidity, chemical and manifold variables on the sensitivity were studied. At the optimized conditions, the linear range for the determination of arsenic was 2.0 × 10−3–0.12 μg ml−1 with the detection limit of 1.20 × 10−9 g ml−1. The relative standard deviations for the eleven replicate determinations of 0.006 μg ml−1 and 0.060 μg ml−1 of arsenic were 1.12% and 1.61%, respectively. The proposed method was applied successfully for the determination of trace arsenic in hair samples with the recoveries of 94.8–104.6%.