| Popis: |
An air-sandwiched sample, reagent solutions and water with a total volume of 317 υ 1 are sequentially delivered by air carrier through PTFE tubing of 1 mm i.d. into a micro cell, where the solutions are mixed to start reaction, and the absorbance is measured against reaction time. This flow system was compared with the stopped-flow/flow-injection and manual batch techniques with regard to the determination of 20–500 ng of sulphide by measuring the decolorization rate of Methyl Orange with bromate. In the proposed flow system, a micro sample is diluted only with limited small volumes of reagent solutions and free from the additional dilution due to dispersion of the reacting solution. Therefore, the absolute sensitivity was ten times that of the manual batch technique using a millilitre-level sample and three times that of the stopped-flow/flow-injection technique. |
