An automated stopped-in-loop flow analysis (SILFA) system is proposed for the successive catalytic
determination of vanadium and iron. The determination of vanadium was based on thep-anisidine
oxidation by potassium bromate in the presence of Tiron as an activator to form a reddish dye, which has
an absorption maximum at 510 nm. The selectivity of the vanadium determination was greatly improved
by adding diphosphate as a masking agent of iron. For the iron determination, an iron-catalyzed oxidative reaction ofp-anisidine by hydrogen peroxide with 1,10-phenanthroline as an activator to produce
a reddish dye (510 nm) was employed. The SILFA system consisted of two peristaltic pumps, two six-port
injection valves, a four-port selection valve, a heater device, a spectrophotometric detector and a data
acquisition device. One six-port injection valve was used for the isolation of a mixed solution of standard/
sample and reagent to promote each catalytic reaction, and another six-port injection valve was used for
switching the reagent for vanadium or iron to achieve selective determination of each analyte. The above
mentioned four-port selection valve was used to select standard solutions or sample. These three valves
and the two peristaltic pumps were controlled by a built-in programmable logic controller in a
touchscreen controller. The obtained results showed that the proposed SILFA monitoring system constituted an effective approach for the selective determination of vanadium and iron. The limits of detection, 0.052 and 0.55mgL
1
, were obtained for vanadium and iron, respectively. The proposed system
was successfully applied to drinking water samples without any preconcentration procedures.
An automated stopped-in-loop flow analysis (SILFA) system is proposed for the successive catalyticdetermination of vanadium and iron. The determination of vanadium was based on thep-anisidineoxidation by potassium bromate in the presence of Tiron as an activator to form a reddish dye, which hasan absorption maximum at 510 nm. The selectivity of the vanadium determination was greatly improvedby adding diphosphate as a masking agent of iron. For the iron determination, an iron-catalyzed oxidative reaction ofp-anisidine by hydrogen peroxide with 1,10-phenanthroline as an activator to producea reddish dye (510 nm) was employed. The SILFA system consisted of two peristaltic pumps, two six-portinjection valves, a four-port selection valve, a heater device, a spectrophotometric detector and a dataacquisition device. One six-port injection valve was used for the isolation of a mixed solution of standard/sample and reagent to promote each catalytic reaction, and another six-port injection valve was used forswitching the reagent for vanadium or iron to achieve selective determination of each analyte. The abovementioned four-port selection valve was used to select standard solutions or sample. These three valvesand the two peristaltic pumps were controlled by a built-in programmable logic controller in atouchscreen controller. The obtained results showed that the proposed SILFA monitoring system constituted an effective approach for the selective determination of vanadium and iron. The limits of detection, 0.052 and 0.55mgL1, were obtained for vanadium and iron, respectively. The proposed systemwas successfully applied to drinking water samples without any preconcentration procedures.
การแปล กรุณารอสักครู่..
