Extracción coacervativa asistida por coprecipitación como alternativa a las técnicas de extracción líquido-líquido convencionales

MAMMANA, SABRINA B.; BERTON, PAULA; ALTAMIRANO, JORGELINA C.

Congreso; 7° CONGRESO MUNDIAL DE JUVENTUDES CIENTÍFICAS, FUNDACIÓN F.I.S.S. FEDERACIÓN INTERNACIONAL DE SOCIEDADES CIENTÍFICAS; 2014

Sample preparation is a crucial step for the analysis of environmental contaminants in water samples. Classical extraction techniques are laborious and consume large volumes or organic solvents to achieve acceptable efficiencies. A suitable alternative is coacervative extraction (CAE). It is based on the separation of an ionic surfactant-rich phase from the sample bulk when it is above its critical micellar concentration and under specific physicochemical properties (pH, salinity, etc) of the solution. The application of CAE for sample preparation also requires obtaining efficient extractions and being coupled with the analytical instrumentation used for analysis of the extracted analytes. In this work, a novel strategy is proposed to facilitate the separation of the surfactant sodium dodecyl sulfate (SDS) by coprecipitation with coagulating/flocculating agents, to achieve a suitable technique to apply in the preparation of real samples. Variables that influence this phenomenon were evaluated by univariate method: surfactant concentration, amount and type of precipitating agent, pH, agitation, temperature, and extraction time. After analysis of the experimental variables, it was observed that to achieve phase separation 4mM SDS, 2 m Al2(SO4)3, pH 6.5 and 3 minutes of extraction time with stirring at room temperature were required. The proposed extraction technique is proposed as an alternative to conventional L-L extraction techniques, due to its efficiency, simplicity, rapidity, and low environmental impact.