ABSTRACT
El método voltametría de onda cuadrada (OSWV) fue validado para la cuantificación de Cd2+ y Pb2+ en aguas superficiales. El estudio fue realizado usando solución Britton-Robinson como electrolito de soporte a pH 4,8, carbón vítreo como electrodo de trabajo, Ag/AgCl como electrodo de referencia y platino como electrodo auxiliar. La técnica presenta un límite de detección 211 ug/L para Pb y 268 ug/L para Cd. La aplicación de la técnica voltamétrica OSWV fue realizada en aguas de la quebrada Las Torres del sector Parque Industrial en Sogamoso (Colombia), hallando una concentración de: Pb2+ 0,750±0,067 mg/L y Cd2+ 0,570±0,071 mg/L, los cuales sobrepasan los límites máximos establecidos por las normas nacionales (Decreto 4728/2010) e internacionales vigentes para aguas residuales. Los resultados fueron contrastados por el método de referencia espectrofotometría de absorción atómica aceptado como referencia, permitiendo deducir que el método electroquímico genera resultados con un nivel de confianza del 95%.
The square wave electrochemical voltammetry method (OSWV) to quantification of cadmium and lead in surface waters was validated. It used a Britton-Robinson buffer as solution supporting electrolyte to pH 4.8, working electrode glassy carbon, Ag/AgCl as reference electrode and platinum as counter electrode. The limit of detection determined was 211 ug/L for Pb and 268 ug/L for Cd. The application of voltammetric technique OSWV was performed in waters of the creek Towers Industrial Park Sector in Sogamoso (Colombia). The ions concentration in the samples analyzed was 0.750±0.067 mg/L for Pb2+ and 0.570±0.071 mg/L for Cd2+, exceeding the national and international standards limits for wastewater. The results obtained by voltammetry were compared with atomic absorption method spectrophotometer traditionally accepted, allowing deducing that the voltammetric method generates results with a confidence level of 95%.
Subject(s)
Humans , Metals, Heavy , Carbon , Electrochemistry , LeadABSTRACT
Objective To investigate the possibility of the domestic reticulated vitreous carbon as a kind of scaffold material for bone tissue engineering,the biocompatibility of domestic reticulated vitreous carbon was first successfully tested with bone marrow stromal cells (BMSCs) in vitro and for bone tissue repair in vivo.Methods From June,2013 to August,2014,the morphology and proliferation of BMSCs co-cultured with scaffold material in vitro was measured.Differences of measurement were compared with single factor analysis of variance to detect the cytotoxicity of reticulated vitreous carbon.In vivo reticulated vitreous carbon were implanted into the bone defect site and the groin.After 12 weeks,the biocompatibility of reticulated vitreous carbon was observed.Results MTT results showed that after 7d co-culture,the survival and proliferation of BMSCs had not been significantly inhibited (P ＞ 0.05).Inverted fluorescence microscope and scanning electron microscope found that newly developed three-dimensional domestic reticulated vitreous carbon could promote adhesion,aggregation and proliferation of BMSCs in vitro.Studies in vivo demonstrate that implanted reticulated vitreous carbon with a high porosity and host bone may produce a stable connection and integration.Conclusion Non-cytotoxic domestic reticulated vitreous carbon can promote the adhesion and proliferation of bone marrow mesenchymal stem cells in vitro and has good bone induction properties in vivo.