INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
Evaluation of quartz tubes as atomization cells for gold determination by thermospray flame furnace atomic absorption spectrometry
EZEQUIEL MORZÁN; ORNELA PIANO; JORGE STRIPEIKIS; M. B. TUDINO
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
PERGAMON-ELSEVIER SCIENCE LTD
Lugar: Amsterdam; Año: 2012 vol. 77 p. 58 - 58
This work describes the development of a new analytical procedure able to determine gold by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) using nickel tubes (NiT) and quartz tubes (QT) as atomization cells. Experiments involving changes in the flow injection operational parameters, reagents concentrations and sizes of the QT were performed in order to optimize sensitivity. Under the same operational conditions, it was observed that the employment of QT increases the sensitivity of gold determination when compared to the nickel tube. Since solutions of highly concentrated hydrochloric acid showed the best performance as carriers, quartz tubes were also preferred due to its greater tolerance to corrosion by mineral acids in comparison to NiT. In addition, changes in the internal diameter of the QT revealed an important improvement in sensitivity for smaller tubes. Under optimized conditions the main figures of merit showed values close to that of graphite furnace atomic absorption spectrometry with the addition of an excellent improvement of the sample throughput. They are: LOD (3s): 0.004 mg mL-1, sensitivity: 0.306 (mg mL-1)-1, RSD% (n=10, 1 mg mL-1): 2.5, linear range: 0.01 - 4 mg mL-1 and sample throughput: 72 h-1. This new method was employed for the determination of gold in homeopathic medicines with no need of sample digestion. Validation of the analytical results will be shown. A fully discussion of the most relevant findings regarding the role of the atomization cell as an strategic key for improving sensitivity will be also provided.