Química Nova ()
DESENVOLVIMENTO DE AMOSTRADOR PASSIVO SENSÍVEL PARA MONITORAMENTO DE POLUIÇÃO ATMOSFÉRICA POR DIÓXIDO DE NITROGÊNIO
Abstract
A passive sampler constructed with a new type of material and used for measurement of ambient nitrogen dioxide is presented. The sampler was constructed with parts of two 50 mL conical centrifuge tubes. The procedure is based on NO2 uptaken on cellulose filter impregnated with triethanolamine. After sampling, the analyte is solubilized and placed to react with Griess-Saltzman solution. The absorbance of the formed complex is determined at 540 nm. A mean relative standard deviation of 9,72% was obtained using samplers exposed in triplicate, and a determination coefficient (R2) of 0,979 was achieved in parallel measurements using the samplers and a commercial NOx monitor. Advantages of the technique include ease of use, the ready availability of components, and excellent sensitivity.
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