2003•Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT)Requires access
Sequential injection standard addition system with a mixing chamber: determination of orthophosphate in waters
Inês P. A. Morais, M. Renata S. Souto, António O.S.S. Rangel
Open publisher page 3 citations
Abstract
A sequential injection system based on the standard addition method using a single standard solution was developed. Successive additions of known amounts of analyte are made to the sample in a mixing chamber placed in a side port of the selection valve; other in-line sample treatments were also performed in the mixing chamber. The proposed method was evaluated by performing experiments with the bromothymol blue dye, and subsequently applied to the spectrophotometric determination of orthophosphate in wastewater, micro algae medium and fish farming water samples. The sample concentration is obtained after plotting a linear graph of analytical signal as a function of the standard mass added to the sample. For the determination of orthophosphate, relative standard deviations were lower than 4 % and the results were in agreement with those obtained by the reference method