High-speed simultaneous ion-exclusion/cation-exchange chromatography of anions and cations on a weakly acidic cation-exchange resin column

The simultaneous ion-exclusion/cation-exchange separation column packed with a polymethacrylate-based weakly acidic cation-exchange resin of 3 microm particle size was used to achieve the simultaneous high-speed separation of anions and cations (Cl(-), NO3(-), SO4(2-), Na(+), K(+), NH4(+), Ca(2+) and Mg(2+)) commonly found in environmental samples. The high-speed simultaneous separation is based on a combination of the ion-exclusion mechanism for the anions and the cation-exchange mechanism for cations. The complete separation of the anions and cations was achieved in 5 min by elution with 15 mM tartaric acid-2.5 mM 18-crown-6 at a flow-rate of 1.5 ml/min. Detection limits at S/N=3 ranged from 0.36 to 0.68 microM for anions and 0.63-0.99 microM for cations. This method has been applied to the simultaneous determination of anions and cations in several environmental waters with satisfactory results.     

Simultaneous determination of anions and cations by ion-exclusion chromatography–cation-exchange chromatography with tartaric acid/18-crown-6 as eluent

Ion-exclusion chromatography–cation-exchange chromatography was developed for the simultaneous separation of common inorganic anions and cations (Cl⁻, NO₃⁻ and SO₄²⁻; Na⁺, NH₄⁺, K⁺, Mg²⁺ and Ca²⁺) on a weakly acidic cation-exchange column by elution with weak acid. Generally, the resolution among these monovalent cations was only moderate, thereby hindering the determination of these analytes in natural-water samples. Therefore, 18-crown-6 was added to the eluent to improve the resolution. A good separation of these anions and cations on a weakly acidic cation-exchange column was achieved in 30 min by elution with 5 mM tartaric acid/6 mM 18-crown-6/methanol–water (7.5:92.5). The ion-exclusion chromatography–cation-exchange chromatography method developed here was successfully applied to the separation of major anions and cations in an environmental water sample.     

Simultaneous ion-exclusion/cation-exchange chromatography of anions and cations in acid rain waters on a weakly acidic cation-exchange resin by elution with sulfosalicylic acid

A simple, selective, and sensitive method for the simultaneous determination of anions (sulfate, nitrate, and chloride) and cations (sodium, ammonium, potassium, magnesium, and calcium) in acid rain waters was developed using ion-exclusion/ cation-exchange chromatography with conductimetric detection. A weakly acidic cation-exchange resin column (Tosho TSKgel OA-PAK-A) and a sulfosalicylic acid-methanol-water eluent was used. With a mobile phase comprising 1.25 mM sulfosalicylic acid in methanol-water (7.5:92.5) at 1.2 ml/min, simultaneous separation and detection of the above anions and cations was achieved in about 30 min. Linear calibration plots of peak area versus concentration were obtained over the concentration ranges 0-1.0 mM for anions (R=0.9991) and 0-0.5 mM for cations (R=0.9994). Detection limits calculated at S/N=3 ranged from 4.2 to 14.8 ppb for the anions and from 2.4 to 12.1 ppb for the cations. The reproducibility of retention times was 0.14-0.15% relative standard deviation (RSD) for anions and 0.18-0.31% for cations, and reproducibility of chromatographic peak areas was 1.22-1.75% RSD for anions and 1.81-2.10% for cations. The method was applied successfully to the simultaneous determination of anions and cations in aerosols transported from mainland China to central Japan, as determined by a meteorological satellite data analyzer.     

同时测定无机离子的改良离子色谱法在河水和废水质量监控中的应用（英文）

In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,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×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×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.     

亲水作用色谱柱与阳离子交换树脂柱结合分离无机离子（英文）

A combination of hydrophilic interaction chromatographic(HILIC) column and a weakly acidic cation-exchange resin(WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography(IC).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC(ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase(ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase(HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC.The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I-> NO-3 > Br-> Cl-> H2PO-4.However,since HILIC-10 could not separate analyte cations,a WCX column(TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions(Na+,NH+4,K+,Mg2+,Ca2+,H2PO-4,Cl-,Br-,NO-3 and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations(RSDs) of analyte ions by the system were in the ranges of 0.02%-0.05% in retention times and 0.18%-5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24-0.30 μmol/L for the cations and 0.31-1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.     

Influence of acidic eluent for retention behaviors of common anions and cations by ion-exclusion/cation-exchange chromatography on a weakly acidic cation-exchange resin in the H+ -form

Influence of acidic eluent on retention behaviors of common anions and cations by ion-exclusion/cation-exchange chromatography (ion-exclusion/CEC) were investigated on a weakly acidic cation-exchange resin in the H(+)-form with conductivity. Sensitivities of analyte ions, especially weak acid anions (F(-) and HCOO(-)), were affected with degree of background conductivity level with pK(a1) (first dissociation constant) of acid in eluent. The retention behaviors of anions and cations were related to that of elution dip induced after eluting acid to separation column and injecting analyte sample. These results were largely dependent on the natures of acid as eluent. Through this study, succinic acid as the eluent was suitable for simultaneous separation of strong acid anions (SO(4)(2-), Cl(-), NO(3)(-) and I(-)), weak acid anions (F(-), HCOO(-) and CH(3)COO(-)), and cations (Na(+), K(+), NH(4)(+), Mg(2+) and Ca(2+)). The separation was achieved in 20 min under the optimum eluent condition, 20 mM succinic acid/2 mM 18-crown-6. Detection limits at S/N=3 ranged from 0.10 to 0.51 microM for strong acid anions, 0.20 to 5.04 microM for weak acid anions and 0.75 to 1.72 microM for cations. The relative standard deviations of peak areas in the repeated chromatographic runs (n=10) were in the range of 1.1-2.9% for anions and 1.8-4.5% for cations. This method was successfully applied to hot spring water containing strong acid anions, weak acid anions and cations, with satisfactory results.     

On-line concentration of s-triazine herbicides in micellar electrokinetic chromatography using a cationic surfactant

A new method for the simultaneous determination of anions (sulfate, nitrate, and chloride) and cations (sodium, ammonium, potassium, magnesium, and calcium) in acid rain waters was investigated using high-performance ion-exclusion/cation-exchange chromatography with conductimetric detection on a separation column packed with a polymethacrylate-based weakly acidic cation-exchange resin in the hydrogen-form and an eluent comprising 1.5 mM sulfosalicylic acid–6 mM 18-crown-6 at pH 2.6, operated at 1.5 ml/min. Effective separation and highly sensitive conductimetric detection for the anions and the cations was achieved in about 14 min. Since the ionic balance (equivalents of anions/equivalents of cations) of acid rain waters of different pH (4.40–4.67) ranged from 0.97 to 0.94, evaluation of the water quality of acid rain was possible. This method was successfully applied to the simultaneous determination of the anions and the cations in acid rain transported from mainland China and North Korea to central Japan monitored by a meteorological satellite data analyzer.     

Vacancy ion-exclusion chromatography of haloacetic acids on a weakly acidic cation-exchange resin

A new and simple approach is described for the determination of the haloacetic acids (such as mono-, di- and trichloroacetic acids) usually found in drinking water as chlorination by-products after disinfection processes and acetic acid. The new approach, termed vacancy ion-exclusion chromatography, is based on an ion-exclusion mechanism but using the sample solution as the mobile phase, pure water as the injected sample, and a weakly acidic cation-exchange resin column (TSKgel OApak-A) as the stationary phase. The addition of sulfuric acid to the mobile phase results in highly sensitive conductivity detection with sharp and well-shaped peaks, leading to excellent and efficient separations. The elution order was sulfuric acid, dichloroacetic acid, monochloroacetic acid, trichloroacetic acid, and acetic acid. The separation of these acids depends on their pKa values. Acids with lower pKa values were eluted earlier than those with higher pKa, except for trichloroacetic acid due to a hydrophobic-adsorption effect occurring as a side-effect of vacancy ion-exclusion chromatography. The detection limits of these acids in the present study with conductivity detection were 3.4 microM for monochloroacetic acid, 0.86 microM for dichloroacetic acid and 0.15 microM for trichloroacetic acid.     

Polydiphenylamine-dodecyl sulfate films for the simultaneous amperometric determination of electroinactive anions and cations in ion-exclusion cation-exchange chromatography

An amperometric detector with two working electrodes both modified with polydiphenylamine-dodecyl sulfate (PDPA-DS) was successfully used for the simultaneous determination of electroinactive anions (SO42-, Cl-, NO3-) and cations (Na+, NH4+ and K+) in single-column ion-exclusion cation-exchange chromatography (IEC-CEC). The PDPA-DS chemical modified electrode (CME) was based on the incorporation of dodecyl sulfate (DS) into PDPA by electropolymerization of diphenylamine in the presence of sodium dodecyl sulfate. The electrochemical responses against the anions and cations at the PDPA-DS CME in differential pulse voltammetry were studied. A set of well-defined peaks of electroinactive anions and cations were obtained. The anions and cations were detected conveniently and reproducibly in a linear concentration range 0.01-5.0 mmol/L and their detection limits were in the range 5-9 micromol/L at a signal-to-noise ratio of 3 (S/N = 3). The proposed method was quick, sensitive and simple and was successfully applied to the analysis of lake water samples. The working electrode was stable over one week period of operation with no evidence of chemical and mechanical deterioration.     

Determination of some aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography with conductimetric detection on a weakly acidic cation-exchange resin column

The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences.     

Selective and simultaneous determination of phosphate and silicate ions in leaching process waters for ceramics glaze raw materials of narutal origin by ion-exclusion chromatography coupled with UV-detection after postcolumn derivatization.

The selective and simultaneous ion-exclusion chromatography (IEC) with UV-detection on a weakly acidic cation-exchange resin column in the H+ -form (TSKgel Super IC-A/C) was developed and applied for the simultaneous determination of phosphate and silicate ions as the water quality parameters required for optimizing the water-leaching process for ceramics glaze raw materials of natural origin including feldspar, woods-ash, and straw-ash. Phosphate and silicate ions in these water-leaching process water samples were separated selectively from the coexisting anions such as sulfate, chloride, nitrate and carbonate ions, based on the ion-exclusion separation mechanism. They were detected selectively and simultaneously by a postcolumn derivatization with molybdenum-yellow using the UV-detector. Under the optimized separation and detection conditions (eluent, 0-1 mM sulfuric acid; reactant, 10 mM sodium molybdate-25 mM sulfuric acid; detector, UV at 370 nm; temperature, 45 degrees C), the linearity of calibration was in the range 0.1 - 10 ppm for both phosphate and silicate ions, and the detection limits at S/N = 3 were 2.58 ppb for silicate ions and 4.75 ppb for phosphate ions. The effectiveness of this method was demonstrated in practical applications to the water-leaching process for some ceramics glaze raw materials.     

Simultaneous separation of inorganic anions and cations by using anion-exchange and cation-exchange columns connected in tandem in ion chromatography

Inorganic anions and cations in environmental waters were determined by ion chromatography. Stationary and mobile phases were examined for the simultaneous separation of both anions and cations. Cations detection by UV detection requires a mobile phase with a UV absorbing additive, which indirectly visualizes cations as negative peaks. Simultaneous separation of anions and cations were achieved when using an eluent that consists of inorganic acid with weak basic amino acid as additives. It was convenient to separate both anions and cations by coupling anion-exchange and cation-exchange columns in tandem. The order of the separation columns connected affected the elution profiles. When the eluent comprises of multiple anions and a single cation, the anion-exchange column should be connected in the upper stream, whereas when the eluent comprises multiple cations and a single anion, the cation-exchange column should be connected in the upper stream. Use of switching valves also allowed simultaneous separation of anions and cations in a single chromatographic run. In the present work, operating conditions were optimized for the simultaneous separation of anions and cations.     

Determination of inorganic cations and anions by ion-exchange chromatography with evaporative light-scattering detection

Evaporative light-scattering detection (ELSD) was investigated for the direct determination of alkali and alkaline-earth cations by cation-exchange chromatography. Successful single run analysis of Na+, K+, Mg2+ and Ca2+ was achieved in 11 min on the Hamilton PRP-X200 column using an aqueous solution of ammonium formate as mobile phase under a salt concentration step gradient mode (20 mM and 100 mM). Surprisingly the use of ELSD reveals a weak retention of inorganic anions (Cl-, NO3-, SO4(2-)) onto the polymeric cation exchanger, which enables the simultaneous determination of inorganic anions (C1- and NO3-) associated with the cations analysed (Na+ and K+).     

Vacancy ion-exclusion chromatography of inorganic acids on a weakly acidic cation-exchange resin column

Vacancy ion-exclusion chromatography (VIEC) for inorganic acids such as H(2)SO(4), HCl, H(3)PO(4), HNO(3), HI and HF is tested on a polymethacrylate-based weakly acidic cation-exchange resin column in the H(+)-form. That is, mixture of inorganic acids in the mobile phase is adsorbed to the resin phase passing through the separation column, and each vacant peak induced by injecting water is determined. Retention times are dependent on the degrees of retention for each analyte in the resin phase. In VIEC, well-shaped peaks of inorganic acids are produced, leading to efficient separations. However, retention behaviors of inorganic acids were strongly affected by the concentrations of the acids in the mobile phase. Sulfosalicylic acid was mixed with inorganic acids in the mobile phase prior to the introduction of a separation column in order to obtain the well-resolutions in the lower concentrations of the acids. By using this method, the separations of inorganic acids could be achieved in the range of 0.01-1 mM, and the linear ranges could be extended over two-orders of magnitude. This is considered since the protonated carboxylic groups fixed on the resin phase were increased with increasing the acid concentrations in the mobile phase, and the penetration effects for the acids to the resin phase were thus enhanced. The detection limits (S/N=3) were below 1.0 microM for all analyte acids. Precision values for retention times were below 0.32% and for peak area were below 0.91%.     

Ion-exclusion chromatography with the direct UV detection of non-absorbing inorganic cations using an anion-exchange conversion column in the iodide-form

An ion-exclusion chromatographic method for the direct UV detection of non-absorbing inorganic cations such as sodium (Na⁺), ammonium (NH₄⁺) and hydrazine (N₂H₅⁺) ions was developed by connecting an anion-exchange column in the I⁻-form after the separation column. For example, NH₄⁺ is converted to a UV-absorbing molecule, NH₄I, by the anion-exchange column in the I⁻-form after the ion-exclusion separation on anion-exchange column in the OH⁻-form with water eluent. As a result, the direct UV detection of Na⁺, NH₄⁺ and N₂H₅⁺ could be successfully obtained as well as the well-resolved separation. The calibration graphs of the analyte cations detected with UV at 230 nm were linear in the range of 0.001-5.0 mM. The detection limits at S/N = 3 of the cations were below 0.1 μM. This method was applied to real water analysis, the determination of NH₄⁺ in river and rain waters, or that of N₂H₅⁺ in boiler water, with the satisfactory results. This could be applied also to low- or non-absorbing anions such as fluoride or hydrogencarbonate ions by the combination of a weakly acidic cation-exchange resin in the H⁺-form as the separation column and the anion-exchange conversion column.     

High-speed ion-exclusion chromatography of dissolved carbon dioxide on a small weakly acidic cation-exchange resin column with ion-exchange enhancement columns of conductivity detection

The high-speed ion-exclusion chromatographic determination of dissolved carbon dioxide, i.e., carbonic acid, hydrogencarbonate or carbonate, with conductivity detection was obtained using a small column packed with a weakly acidic cation-exchange resin in the H+-form (40 mm long x 4.6 mm i.d., 3 microm-particle and 0.1 meq./ml-capacity). Two different ion-exchange resin columns, which were a strongly acidic cation-exchange resin in the K+-form and a strongly basic anion-exchange resin in the OH- -form, were connected after the separation column. The sequence of columns could convert dissolved carbon dioxide to KOH having high conductivity response. The enhancement effect for dissolved carbon dioxide could retain even on the vast chromatographic runs, by using the enhancement columns with high ion-exchange capacity above 1.0 meq./ml. The retention time was in 60 s at flow-rate of 1.2 ml/min. The calibration graph of dissolved carbon dioxide estimated as H2CO3- was linear in the range of 0.005-10 mM. The detection limit at signal to noise of 3 was 0.15 microM as H2CO3-. This method was applicable to several rainwater and tap water samples.     

强碱阴离子交换树脂及碱性洗脱剂的离子排阻/阴离子交换色谱法同时测定NH4+ ，NO2-和NO3-（英文）

Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclusion/penetration effect for cations and the anion-exchange effect for anions to anion-exchange resin phase.This system is useful for simultaneous separation and determination of ammonium ion(NH+4),nitrite ion(NO-2),and nitrate ion(NO-3) in water samples.The resolution of analyte ions can be manipulated by changing the concentration of base in eluent on a polystyrene-divinylbenzene based strongly basic anion-exchange resin column.In this study,several separation columns,which consisted of different particle sizes,different functional groups and different anion-exchange capacities,were compared.As the results,the separation column with the smaller anion-exchange capacity(TSKgel Super IC-Anion) showed well-resolved separation of cations and anions.In the optimization of the basic eluent,lithium hydroxide(LiOH) was used as the eluent and the optimal concentration was concluded to be 2 mmol/L,considering the resolution of analyte ions and the whole retention times.In the optimal conditions,the relative standard deviations of the peak areas and the retention times of NH+4,NO-2,and NO-3 ranged 1.28%-3.57% and 0.54%-1.55%,respectively.The limits of detection at signal-to-noise of 3 were 4.10 μmol/L for NH+4,1.87 μmol/L for NO-2 and 2.83 μmol/L for NO-3.     

Successive non-suppressed ion chromatography of common cations and anions using dual columns with single eluent

A successive non-suppressed ion chromatography (IC) system for the determination of common cations (Na+, K+, Mg2+, Ca2+) and anions (Cl-, Br-, NO3-, SO4(2-)) was developed, using two separation columns and a single eluent. 5-Sulfoisophthalic acid eluent was very suitable for such separations with a commercially available cation-exchange column for the mono- and di-valent cations and with an ODS column coated with cetyltrimethylammonium for the anions. Both cations and anions were detected with conductimetrically high sensitivity without any suppressor. After injecting an aliquot of sample solution, the solvent front from the cation-exchange column, including most of the anionic species, was firstly accumulated into the additional 2 ml accumulation loop for 60 s, while the cation IC was performed. Subsequently, the accumulated fraction was introduced into the anion-exchange column and chromatographed. Relative standard deviations (RSDs) of retention times and conductimetric area responses for common cations were within 6% and within 4%, respectively. The linear relationships between molar concentration and detector response ranged from 0.01 to 1.00 mM with r2 of 0.9994 for Na+, 0.9992 for K+, 0.9993 for Mg2+, and 0.9988 for Ca2+. The successive anion IC through the accumulating process was also quantitative, with 95% recovery or over for each analyte. The linear ranges were between 0.01 and 1.00 mM with r2 of 0.9996 for Cl-, 0.9997 for Br-, 0.9993 for NO3-, and 0.9984 for SO4(2-). The method was applied to the determination of common cations and anions in several mineral waters and a hot spring water.     

改进的离子色谱系统监测重庆嘉陵江水质（英文）

The w ater quality monitoring operation to evaluate the w ater quality of polluted river is an extremely im po rtant task fo r the river-w atershed m anagem ent/co ntro l based o n the enviro nm ental po licy.In this study,the no vel,sim ple and co nvenient w ater quality m o nito ring o f Jialing-River in Cho ngqing,China w as carried o ut using an advanced io n chro m ato graphy(IC) co nsisting o f io n-ex clusio n/catio n-ex change chro m ato graphy(IEC/CEC) with conductivity detection for determining simultaneously the common anions such as SO 2 4,Cl,and NO 3 and the catio ns such as Na +,NH + 4,K +,Mg 2 +,and Ca 2 +,the ion-exclusion chromatography(IEC) w ith visible detectio n fo r determ ining sim ultaneo usly the nutrient co m po nents such as pho sphate and silicate io ns,and the IEC w ith the enhanced co nductivity detectio n using a po st co lum n o f K +-fo rm catio n-ex change resin fo r determ ining HCO 3-alkalinity as an ino rganic-carbo n so urce fo r bio m ass synthesis in bio lo gical reactio n pro cess under the aero bic co nditio ns.Acco rding to the io nic balance theo ry betw een the to tal equivalent co ncentratio ns o f anio ns and catio ns,the w ater quality evaluatio n o f the Jialing-River w aters taking at different sam pling sites in Cho ngqing m etro po litan area w as carried o ut using the advanced IC system.As a result,the effectiveness o f this no vel w ater quality m o nito ring m etho do lo gy using the IC system w as dem o nstrated o n the several practical applicatio ns to a typical bio lo gical sew age treatm ent plant o n Jialing-River o f Cho ngqing.     

Polydiphenylamine-dodecyl sulfate films for the simultaneous amperometric determination of electroinactive anions and cations in ion-exclusion cation-exchange chromatography

An amperometric detector with two working electrodes both modified with polydiphenylamine-dodecyl sulfate (PDPA-DS) was successfully used for the simultaneous determination of electroinactive anions (SO₄ ^2–, Cl^–, NO₃ ^–) and cations (Na⁺, NH₄ ⁺ and K⁺) in single-column ion-exclusion cation-exchange chromatography (IEC-CEC). The PDPA-DS chemical modified electrode (CME) was based on the incorporation of dodecyl sulfate (DS) into PDPA by electropolymerization of diphenylamine in the presence of sodium dodecyl sulfate. The electrochemical responses against the anions and cations at the PDPA-DS CME in differential pulse voltammetry were studied. A set of well-defined peaks of electroinactive anions and cations were obtained. The anions and cations were detected conveniently and reproducibly in a linear concentration range 0.01–5.0 mmol/L and their detection limits were in the range 5–9 μmol/L at a signal-to-noise ratio of 3 (S/N = 3). The proposed method was quick, sensitive and simple and was successfully applied to the analysis of lake water samples. The working electrode was stable over one week period of operation with no evidence of chemical and mechanical deterioration.