Simultaneous determination of selected transition metal cations and inorganic anions by ion chromatography

Abstract

The retention times and detection limits of a selected group of six transition metal cations and four inorganic anions determined using a simultaneous separation and detection system are presented. The over-all analysis time is usually less than 20 min and detection limits are at or near the 1 p.p.m. level. Two different systems are described, the first for the repetitive analysis of similar solutions and the second for samples of widely varying composition.

Continuous and simultaneous determination of anions and cations in rainwater by ion chromatography

“…The gain of the conductimetric detector was 1 mS cm 21 , the range was 1, the response was STD (response time 1 s) and the polarity was positive. The eluent flow rate was 1.2 mL min 21 (column pressure 38 kg cm 22 ). The baseline drift of the chromatograms was minimized by keeping the column temperature at 25 °C.…”

“…For the retention of monovalent weak acid anions such as NO 2 2 , F 2 , HCOO 2 and CH 3 COO 2 , t R depended on their pK 1 values (NO 2 2 < F 2 < HCOO 2 < CH 3 COO 2 ). For the retention of mono-and divalent strong acid anions such as SO 4 22 , S 2 O 3 22 and Cl 2 , the t R depended on their charge (Cl 2 < SO 4 22 = S 2 O 3 22 ) rather than their pK 1 values (complete dissociation). The t R of NO 3 2 depended on the hydrophobic adsorption of NO 3 2 by the polyacrylate resin rather than the differences in the charge and the pK 1 values, so the t R of NO 3 2 was larger than that of PO 4 32 , which is a weak acid anion (pK 1 = 2.1).…”

“…Acid rain, mainly caused by SO 2 and NO x , is now a very harmful environmental problem. The major cations in rainwater are H + , Na + , NH 4 + , K + , Mg 2+ and Ca 2+ and the major anions are Cl 2 , NO 3 2 , SO 4 22 and HCO 3 2 ; other ions such as F 2 , CH 3 COO 2 , HCOO 2 and NO 2 2 are also sometimes present in rainwater. The continuous and simultaneous determination of these ions in rainwater could intuitively provide long-term information on rainfall for elucidating the major reasons for acid rain formation.…”

“…There are several basic ionexchange separation methods for the simultaneous determination of anions and cations by IC, such as the use of chelating agents as eluents, 14,15 on bifunctional ion-exchange resin, 16 on mixed-bed columns [17][18][19] and on suitably connected anion-and cation-exchange columns. [20][21][22][23] However, they could only achieve the simultaneous determination of these anions and cations to a certain extent, and their processes are complicated. Tanaka et al [24][25][26][27] separated common anions and cations simultaneously using tartaric acid solution as eluent by singlecolumn ion-exclusion chromatography-cation-exchange chromatography based on ion-exclusion and cation-exchange mechanisms, that is, the separation of anions was by ion exclusion and that of cations was by cation exchange.…”

The Simultaneous Analysis of Metal-EDTA Complexes and Inorganic Anions by Suppressed Ion Chromatography

“…One of the most effective developments in ion chromatog raphy in the last several years is the introduction of a procedure that allows the simultaneous separation of metal cations and simple anions. The interest in techniques that yield complete anion and cation sample characterization has grown in the past years (2). Methods developed for this purpose involve the * Author to whom correspondence should be addressed.…”