Simultaneous amperometric detection of electroinactive anions and cations in ion chromatography

摘要: An amperometric detector with two working electrodes modified with polydiphenylamine (PDPA) and dodecyl sulfate (PDPA-DS) was successfully used for the simultaneous determination of electroinactive anions (SO42−, Cl−, NO3−) cations (Na+, NH4+ K+) in single-column ion-exclusion chromatography–cation-exchange chromatography (IEC-CEC). The PDPA-DS chemically electrode (CME) was based on incorporation (DS) into PDPA by electropolymerization diphenylamine (DPA) presence surfactant. The electrochemical responses against differential pulse voltammetry were studied. A set well-defined peaks obtained. relative standard deviations (RSDs) chromatographic peak height (nA) all <4.4% those <4.1%. were detected conveniently reproducibly linear concentration range 6.0 ×10−6–5.0 × 10−3 mol L−1 their correlation coefficients >0.990. Their detection limits investigated using 3s (where s represents deviation a blank solution, n = 11). They 9.86 10−7 mol SO42−, 6.92 × 7.86 L−1 NO3−, 10−7 Na+, 9.79 NH4+ 8.94 K+. recoveries cations this method range 97.8–103%. proposed method rapid, sensitive simple applied to analysis rainwater samples. Both stable during 1 week period operation no evidence chemical or mechanical deterioration.