A flow system with in-line blank correction applied to the spectrophotometric determination of total iron and chromium (VI) in wastewaters

摘要

A flow system using the sample as the carrierwith a propulsion device located after the detector is presented.This approach allows the correction of the intrinsiccolor of the sample, as it provides baseline adjustmentfor each sample. A confluence situated just after the selectionvalve allows the sample composition to be adjustedfor the colorimetric measurement. The developed methodologywas applied to the colorimetric determination of totalFe and Cr (VI) in wastewaters at 0.1–6.0 mg L–1 and0.03–1.0 mg L–1, respectively. RSDs lower than 3% and asampling rate of approximately 40 h–1 were obtained