Simultaneous Determination of Inorganic Anions by Sequential Injection Chromatography System Constructed from a Monolithic Column and a Microfluidic Polymer Chip with an Embedded Ion-Selective Electrode

A sequential injection chromatography (SIC) constructed from a short monolithic column and a microfluidic polymer chip with an embedded Cl ion-selective electrode (Cl-ISE) as a detector was developed for simultaneous determination of common inorganic anions. Under the optimal flow conditions of the SIC system, the determination range for Cl, NO2 , Br, NO3 ions was as follows: For Cl ion in a concentration range from 1.0 x 10 to 5.0 x 10 mol dm, for NO2 ion in the concentration range from 1.0 x 10 to 5.0 x 10 mol dm, for Br ion in the concentration range from 1.0 x 10 to 5.0 x 10 mol dm, and for NO3 ion in the concentration range from 3.0 x 10 to 1.0 x 10 mol dm, respectively. Limit of detection, defined as S/N=3, was ca. 3.0 x 10 mol dm for Cl, NO2 , Br, NO3 ions.