Article ID Journal Published Year Pages File Type
1247429 Talanta 2006 8 Pages PDF
Abstract

A sensitive SIA method was developed for sulphate determination in automotive fuel ethanol. This method was based on the reaction of sulphate with barium–dimethylsulphonazo(III) leading to a decrease on the magnitude of analytical signal monitored at 665 nm. Alcohol fuel samples were previously burned up to avoid matrix effects for sulphate determinations. Binary sampling and stop-flow strategies were used to increase the sensitivity of the method. The optimization of analytical parameter was performed by response surface method using Box–Behnker and central composite designs. The proposed sequential flow procedure permits to determine up to 10.0 mg SO42− l−1 with R.S.D. <2.5% and limit of detection of 0.27 mg l−1. The method has been successfully applied for sulphate determination in automotive fuel alcohol and the results agreed with the reference volumetric method. In the optimized condition the SIA system carried out 27 samples per hour.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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