| Autor: |
Pinheiro BS; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil., Gimenes LL; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil., Moreira AJ; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil., de Araújo AF; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil., Freschi CD; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil., Freschi GPG; a LAFFEQ, Institute of Science and Technology , Federal University of Alfenas, UNIFAL-MG , Poços de Caldas , MG , Brazil. |
| Abstrakt: |
This work presents an alternative method for arsenic speciation using the nano-TiO 2 hydride generation photocatalytic hydride generation (PCHG) system, which is easily separated from the medium. Nano-TiO 2 was studied as photocatalyst to reduction of arsenic species by UV-induced with formic acid and atomic absorption detection of different forms of arsenic [As (III), As (V), dimethylarsinic acid (DMA)] in environmental samples (water, sediment and plant). The effect of the average pH, the organic acid concentration, the ultraviolet irradiation time and their amount were investigated. With the presence of formic acid, the process was more effective in the reduction of arsenic when compared to other organic acids, mainly acetic acid. In addition, the photocatalytic hydride generation and flame atomic absorption spectrometry (nano-TiO 2 /PCHG-FAAS) increased the identification and quantification of different arsenic species. The ultrasound extraction procedure was used as a method to prepare samples with solutions of 1.0 mol L -1 phosphoric acid. The accuracy of the measurements (n = 12), calculated as relative standard deviation, was less than 8.6%. The detection limits for As (III) and As (total) in samples were 0.418 and 0.574 μg g -1 , respectively. |
