Development and validation of an analytical method for the extraction and quantification of soluble sulfates in red clay

Abstract

Development and validation of an analytical method for the extraction and quantification of soluble sulfates in red clay(Desenvolvimento e validação de um método analítico para a extração e quantificação de sulfatos solúveis em argilas vermelhas) AbstractIn this work a fast and environmentally friendly method for the extraction and quantification of soluble sulphates in red clay using microwave assisted extraction (MAE) and determination by turbidimetry was developed and validated. The favorable conditions for the extraction of soluble sulphates in red clay by MAE were: 1 g of sample, with particle size of 63 μm, dissolved in 50 mL of distilled water, it was extracted using a microwave oven with 70% of power during 5 min, later the sample was centrifuged during 5 min and then filtered. The soluble sulphates in red clays were quantified at 420 nm. The procedure proposed showed linear behaviour in the tested rank (5-7000 mg SO 4 2-/kg of clay) with R 2 0.9993. The limits of detection and quantification were 4.30 and 14.33 mg/kg, respectively, with a variation coefficient of 1.41%. The method proposed in this work allows to determine soluble sulphates in red clay with a recovery of 94%. Keywords: red clay, soluble sulphates, microwave assisted extraction (MAE), turbidimetry. Resumo Neste trabalho foi desenvolvido e validado um método rápido e inofensivo ao ambiente para a extração e quantificação de sulfatos solúveis em argilas vermelhas usando extração assistida por microondas (MAE

Exotic Spartina alterniflora invasion increases CH4 while reduces CO2 emissions from mangrove wetland soils in southeastern China

“…Pore-water salinity was determined after centrifugation of soil using a MASTER-S/MillM salinity refractometer (ATAGO, Japan). Pore-water SO 4 2− concentration was measured using a turbidimetric method according to the methods proposed by Cáceres and colleagues 59 . Soil inorganic N (NH 4 + , NO 3 − and NO 2− ) concentration were analyzed using AA3 Auto Analyzer 3 (Seal, Germany) after extracted with 2 mol/L KCl as described by Chen et al .…”

Caracterización de materiales arcillosos y su potencial aplicación en la industria cerámica

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“…(Ercikdi et al, 2009). Therefore, in many of these industrial processes, the concentration of sulphate ions is an important parameter that must be determined easily and with high precision (Caceres et al, 2015). On the other hand, wastewaters resulting from such industrial activities also contain sulphate ions in different concentrations, and their determination is of real interest, technological and environmental point of view.…”