Sequential injection analysis of chloride and nitrate in waters with improved accuracy using potentiometric detection

Santos, E; Montenegro, MC; Couto, C; Araújo, AN; Pimentel, MF; da Silva, VL

HERO ID

1332553

Reference Type

Journal Article

Year

2004

Language

English

PMID

18969492

HERO ID 1332553
In Press No
Year 2004
Title Sequential injection analysis of chloride and nitrate in waters with improved accuracy using potentiometric detection
Authors Santos, E; Montenegro, MC; Couto, C; Araújo, AN; Pimentel, MF; da Silva, VL
Journal Talanta
Volume 63
Issue 3
Page Numbers 721-727
Abstract Accurate simultaneous analysis of different anionic species using ion-selective electrodes (ISEs) can be achieved even for non-specific sensors by resorting to an ordinary least squares multiple regression in the vicinity of the predicted concentrations. In this work the potentialities of this approach are evidenced by the determination of nitrate and chloride in synthetic and real water samples in which chloride concentration was significantly higher than nitrate. An AgCl/Ag(2)S electrode based on a homogeneous crystalline membrane together with a PVC electrode based on tert-octylammonium bromide dissolved in dibutylphthalate were used as potentiometric detectors for chloride and nitrate, respectively. For the implementation of the procedure, an automatic system based on sequential injection analysis was used. The results obtained by the standard addition method were biased for low concentrations of nitrate and were dependant on the relative proportion of NO(3)(-)/Cl(-). The results obtained by the proposed methodology for chloride determination were slightly better when compared to those obtained by the standard addition method. In relation to nitrate determination, the proposed methodology yielded values with a relative root mean square error of prediction (RRMSEP) of 2.8%, while for standard addition calibration, mean error values were approximately 12.1%.
Doi 10.1016/j.talanta.2003.12.031
Pmid 18969492
Wosid WOS:000221735500032
Url http://www.sciencedirect.com/science/article/pii/S0039914003007859
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword multiple regression; standard addition method; SIA; chloride/nitrate; waters