Desenvolvimento de procedimento analítico empregando multicomutação em fluxo para determinação fotométrica de cloreto em amostras de coque de petróleo / Development of analytical procedure employing multicommutation for photometric determination of chloride in petroleum coke

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

In this work was developed an analytical procedure employing multicommutation for the photometric determination of chloride in petroleum coke. The procedure was based on the photometric method described on Stand Method, where the reaction between mercury(II) thyocyanate and chloride causes the displacement of the thyocyanate ions, which reacted with iron(III) forming a compound that monitored at 472 nm. Two analysis modules were designed employing three-way and pinch solenoid valves. After the optimizing of the analytical parameters related to analysis module that employed three-way solenoid valves, the analytical curve presented a linear response in the concentration range of 0.25 to 4.0 mg L-1 (R = 0.997). A detection limit of 0.12 mg L-1 chloride, a relative standard deviation of 1.7 % (n = 15) and a sampling frequency of 50 determination per hour were also achieved. The second analysis module was designed to avoid acidification step of sample and reference solutions that was carried out off line to prevent bubbled delivering. The analytical curve presented a linear response within the concentration range of 0.25 up to 6.0 mg L-1 chloride (R=0.999). Detection limit of 0.04 mg L-1, standard deviation of 0.8 % (n=15), and sampling frequency of 50 determination per hours were of achieved. The proposed system was used for the determination of chloride in petroleum coke and also in certified material.

ASSUNTO(S)

multicomutação cloreto coque de petróleo multicommutation petroleum coke chloride

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