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(I...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.展开更多
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+),nutri...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.展开更多
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 ...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.展开更多
To enhance the conductivity detection sensitivity of common anions(Na-anions) in electrostatic ion chromatography(EIC) by elution with water,a conductivity enhancement column packed with strong acid cation exchange re...To enhance the conductivity detection sensitivity of common anions(Na-anions) in electrostatic ion chromatography(EIC) by elution with water,a conductivity enhancement column packed with strong acid cation exchange resin in the H-form was inserted between an octadecyl silane(ODS)-silica separation column modified with zwitterionic surfactant(CHAPS: 3-{(3-cholamidopropyl)-dimethylammonio}propanesulfonate) and a conductivity detector.Specifically,the Na-anion pairing is converted to H-anion pairing after the EIC separation and then detected sensitively by the conductivity detector.The effects of conductivity enhancement and suppression in the EIC by the enhanced conductivity detection were characterized for the common strong acid anions such as SO2-4,Cl-,NO-3,I-and ClO-4 and weak acid anions such as F-,NO-2,HCOO-,CH3COO-and HCO-3.For the conductivity enhancement effect in the EIC,it is found that the conductivity of measured for all strong acid anions(Na-anions) was enhanced according to the theoretical conductivity predicted for H-anions and that of the measured for weak acid anions was suppressed depending on their pKa of H-anions.For the calibration linearity in the EIC,the strong acid anions were linear(r2=0.99-1.00) because the degree of dissociation is almost 1.0 over all the concentration range and that of the weak acid anions was non-linear because the degree of dissociation decreased by increasing the concentration of the weak acid anions.In conclusion,the EIC by enhanced conductivity detection was recognized to be useful only for the strong acid anions in terms of conductivity detection and calibration linearity.展开更多
基金supported by Grant-in-Aid for Scientific Research(23615003)in Japan Society for the Promotion of Science(JSPS)
文摘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.
基金supported by the Chugoku Regional Development Bureau of the Ministry of Land,Infrastructure,Transport and Tourism,Japan
文摘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.
文摘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.
基金supported from Fellow ships Program for Young Scientists of the Japan Society for the Promotion of Scienceon FY2011
文摘To enhance the conductivity detection sensitivity of common anions(Na-anions) in electrostatic ion chromatography(EIC) by elution with water,a conductivity enhancement column packed with strong acid cation exchange resin in the H-form was inserted between an octadecyl silane(ODS)-silica separation column modified with zwitterionic surfactant(CHAPS: 3-{(3-cholamidopropyl)-dimethylammonio}propanesulfonate) and a conductivity detector.Specifically,the Na-anion pairing is converted to H-anion pairing after the EIC separation and then detected sensitively by the conductivity detector.The effects of conductivity enhancement and suppression in the EIC by the enhanced conductivity detection were characterized for the common strong acid anions such as SO2-4,Cl-,NO-3,I-and ClO-4 and weak acid anions such as F-,NO-2,HCOO-,CH3COO-and HCO-3.For the conductivity enhancement effect in the EIC,it is found that the conductivity of measured for all strong acid anions(Na-anions) was enhanced according to the theoretical conductivity predicted for H-anions and that of the measured for weak acid anions was suppressed depending on their pKa of H-anions.For the calibration linearity in the EIC,the strong acid anions were linear(r2=0.99-1.00) because the degree of dissociation is almost 1.0 over all the concentration range and that of the weak acid anions was non-linear because the degree of dissociation decreased by increasing the concentration of the weak acid anions.In conclusion,the EIC by enhanced conductivity detection was recognized to be useful only for the strong acid anions in terms of conductivity detection and calibration linearity.
