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This technical note illustrates the possibility of using a conductivity cell electrode (CCE) as an ion chromatography (IC) detector to extend the application fields of this analytical technique. A conventional non-suppressed IC system consists of an eluent delivery pump, a separation column, column oven, and conductivity detector (CD). In this study, the conventional CD, which is one of the expensive parts of the instrument, is replaced with a relatively inexpensive CCE, leading to comparable peak resolution, detection sensitivity, and relative standard deviation. The separation effectiveness was retained and the developed IC-CCE system was successfully applied to the simultaneous separation of inorganic anions (SO 4 2- , Cl - , and NO 3 - ) and cations (Na + , NH 4 + , K + , Mg 2+ , and Ca 2+ ) in three natural mineral water samples, with good accordance between the monitored values obtained using the CCE and CD. The commercially available CCE is potentially suitable for application as an IC detector for monitoring ionic components with overall IC cost reduction.

Multicomponent simultaneous analysis is important for management programs, which are required in beer industries because the beer constituents measure by combining several methods in the present. In response to a requirement, our research group developed single sample injection ion chromatography systems, which comprise ion-exclusion/cation-exchange chromatography (IEC/CEC) and post-column derivatization and show promise for simultaneously determining concentrations of organic and inorganic species and alcohol commonly found in beer. Optimal chromatographic resolutions for determining 17 different species in beer samples by IEC/CEC were obtained on a H + -formed weakly acidic cation-exchange resin column with an eluent comprising 2 mM phthalic acid and 1 mM 18-crown-6. Consequently, the usefulness of developed method for monitoring beer samples was demonstrated in terms of beneficial information such as dependency of K + concentration on the malt amount, influences of organic anion concentrations on different types of bottling methods, and validation of ethanol concentrations displayed in the ingredient table., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Herein, we describe indirect UV detection-ion-exclusion/cation-exchange chromatography (IEC/CEC) on a weakly acidic cation-exchange resin in the H(+)-form (TSKgel Super IC-A/C) using sulfosalicylic acid as the eluent. The goal of the study was to characterize the peaks detected by UV detector. The peak directions of analyte ions in UV at 315 nm were negative because the molar absorbance coefficients of analyte anions and cations were lower than that of the sulfosalicylic acid eluent. Good chromatographic resolution and high signal-to-noise ratios of analyte ions were obtained for the separations performed using 1.1 mM sulfosalicylic acid and 1.5 mM 18-crown-6 as the eluent. The relative standard deviations (RSDs) of the peak areas ranged from 0.6 to 4.9%. Lower detection limits of the analytes were achieved using indirect UV detection at 315 nm (0.23 - 0.98 μM) than those obtained with conductometric detection (CD) (0.61 - 2.1 μM) under the optimized elution conditions. The calibration curves were linear in the range from 0.01 to 1.0 mM except for Cl(-), which was from 0.02 to 2.0 mM. The present method was successfully applied to determine common inorganic ions in a pond water sample.

We describe the ion chromatographic separation of inorganic anions using a diol-stationary phase column (-CH(OH)CH(2)OH; diol-column) without charged functional groups. Anions were separated using acidic eluent as in typical anion-exchange chromatography. The retention volumes of anions on the diol-column increased with increasing H(+) concentration in the eluent. The anion-exchange capacities of diol-columns in the acidic eluent (pH 2.8) were larger than that of zwitterionic stationary phase column but smaller than that of an anion-exchange column. The separation of anions using the diol-column was strongly affected by the interaction of H(+) ions with the diol-functional groups and by the types of the eluents. In particular, the selection of the eluent was very important for controlling the retention time and resolution. Good separation was obtained using a diol-column (HILIC-10) with 5 mM phthalic acid as eluent. The limits of detection at a signal-to-noise ratio of 3 ranged from 1.2 to 2.7 μM with relative standard deviations (RSD, n=5) of 0.04-0.07% for the retention time and 0.4-2.0% for the peak areas. This method was successfully applied to the determination of H(2)PO(4)(-), Cl(-), and NO(3)(-) in a liquid fertilizer sample., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In this study, our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions (SO4(2-), Cl(-) and NO3(-)) and cations (Na+, NH4+, K+, Mg2+, and Ca2+), nutrients (phosphate and silicate) and hydrogen ion/alkalinity are summarized first. Then, the applications using these methods for monitoring environmental water quality are also presented. For the determination of common anions and cations with nutrients, the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C (Tosoh, 150 mm x 6.0 mm i. d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry. For the determination of hydrogen ion/alkalinity, the separation was conducted by TSKgel ODS-100Z column (Tosoh, 150 mm x 4.5 mm i. d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector. The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant. Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed. From these results, our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.