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Se presenta la evaluacion del procedimiento de extraccion secuencial aprobado por la BCR (BCR, por sus siglas en ingles, Community Bureau of Reference) para determinar metales en muestras de sedimentos del rio Catatumbo, Venezuela. Las fracciones consistieron en 4 etapas: en la primera, llamada intercambiable, se extrajo utilizando acido acetico; la segunda, o reducible, con hidroxicloruro de amonio; la tercera, u oxidable, con peroxido de hidrogeno y acetato de amonio y la residual, que es la etapa remanente, se digirio con agua regia. El analisis se realizo por espectrometria de absorcion atomica con llama (FAAS), horno de grafito (ETAAS) y espectrometria de emision atomica con plasma inductivamente acoplado (ICP-AES). Los metales determinados fueron Pb y V. Las determinaciones por FAAS, ETAAS e ICP-AES indicaron que no hubo diferencias estadisticamente significativas (p < 0,05) cuando se compararon los resultados de 24 muestras de sedimentos del rio Catatumbo realizadas por triplicado. La exactitud encontrada sumando las cuatro etapas de la BCR para Pb y V fueron comparables a los resultados obtenidos por digestion acida, lo cual indica que el procedimiento es adecuado para la cuantificacion de los metales estudiados. El Pb y V se encontro mayormente (55-97 %) en la etapa residual lo que los hace no disponibles. Palabras clave: digestion acida, extraccion BCR, sedimento, plomo, vanadio  Abstract: The aim of the present work is the evaluation of the procedure of sequential extraction approved by the BCR and used to determine metals in samples of sediments from Catatumbo River in Venezuela. The fractions consisted in four (4) stages: the first one or interchangeable was extracted using acetic acid, the second one or reducible with ammonia hydroxi-chloride, the third one or oxidable with hydrogen peroxide and ammonium acetate and the residual which is the remnant stage was digested with aqua regia. The analysis was made by Flame Atomic Absorption Spectrometry (FAAS), Electrothermal Atomisation Atomic Absorption Spectrometry (ETA-AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The metals evaluated were Pb and V. The evaluations for FAAS, ETA-AS and ICP-AES indicated that there were not statistically significant differences (p <0.05) when the results of 24 samples of sediments from the Catatumbo River carried out in triplicate were compared. The exact result found by adding the four stages of the BCR for Pb and V were comparable to the results obtained by acid digestion. The Pb and V were found mainly (55-97 %) in the residual stage which makes them not available and these results are comparable to other studies published. Key words: Acid Digestion, Extraction of BCR, sediment, Pb, V

Extracción secuencial de plomo y vanadio en sedimentos del río Catatumbo utilizando FAAS, ETAAS e ICP-AES