YS-50阳离子色谱柱抑制电导法测定河水中阳离子

建立了ShodexICYS-50阳离子色谱柱测定河水中阳离子的离子色谱方法。以甲基磺酸(4mmol/L)为淋洗液,流速为1mL/min,抑制电导法检测,每个样品的分析时间为20min。在优化的实验条件下,Na+、NH4+、K+、Mg2+、Ca2+的检出限分别为1.30、1.44、3.18、2.31、5.17μg/L;加标回收率为91.24%～104.8%。并将此色谱柱与DionexIonpacCS12A进行分析比较,两根柱子的检测结果数据一致。研究结果表明,方法简便、快速、准确可靠,适合对河水此类复杂样品的检测。     

单柱离子排斥-阳离子交换色谱法测定酸雨组分

采用单柱离子色谱系统和电导检测的方法,首次以ＤＬ－苹果酸－甲醇水溶液为淋洗液,简便、有效地同时分离、检测了溶液ＳＯ＾－２４、Ｃｌ＾－、ＮＯ＾－３、Ｆ＾－、Ｎａ＾＋、ＮＨ＾＋４、Ｋ＾＋、Ｍｇ＾２＋、Ｃａ＾２＋９种离子。研究了ＤＬ－苹果酸浓度、甲醇浓度、流速和温度对各离子保留时间的影响。方法用于上海部分地区降水中的阴、阳离子分析,并与其它方法对比,结果良好。     

碱金属和碱土金属离子在反相高效液相色谱柱上的保留机理

发现以酒石酸和吡啶二甲酸等羧酸水溶液作淋洗剂时，钠，铵，钾，镁和钙等碱金属及碱土金属离子在ＯＤＳ反相高效液相色谱柱上有明显的保留，而且相互之间能达到一定程度的分离。单独用分配或疏水作用等反相高效液相色谱的保留机理难以解释其保留行为。为此，作者提出了动态包固定相机理，即认为羧酸根阴离子因其疏水性在ＯＤＳ固定相有保留，在固定相表面形成具有羧酸基阳离子交换树脂功能的动态包覆固定相。     

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.     

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.     

Determination of common inorganic anions and cations by non-suppressed ion chromatography with column switching

An ion chromatography (IC) method has been proposed for the determination of seven common inorganic anions (F(-), H(2)PO(4)(-), NO(2)(-), Cl(-), Br(-), NO(3)(-), and SO(4)(2-)) and/or five common inorganic cations (Na(+), NH(4)(+), K(+), Mg(2+), and Ca(2+)) using a single pump, a single eluent and a single detector. The present system used cation-exchange and anion-exchange columns connected in series via a single 10-port switching valve. The 10-port valve was switched for the separation of either cations or anions in a single chromatographic run. When 1.0mM trimellitic acid (pH 2.94) was used as the eluent, the seven anions and the five cations could be separated on the anion-exchange column and the cation-exchange column, respectively. The elution order was found to be F(-)相似文献   

Indirect ultraviolet spectrophotometric detection in the ion chromatography of common mono- and divalent cations on an aluminium adsorbing silica gel column with tyramine-containing crown ethers as eluent

The application of laboratory-made aluminium-adsorbing silica gel (Al-Silica) as a cation-exchange stationary phase to ion chromatography-indirect photometric detection (IC-IPD) for common mono- and divalent cations (Li+, Na+, NH+, K+, Mg2+ and Ca2+) was carried out by using protonated tyramine (4-aminoethylphenol) as eluent ion. When using 1.2 mM tyramine-0.2 mM oxalic acid at pH 4.5 as eluent, incomplete separation of the monovalent cations and complete separation of the divalent cations were achieved in 17 min. Then, the addition of crown ethers in the eluent was carried out for the complete separation of the mono- and divalent cations. As a result, when using 1.2 mM tyramine--0.2 mM oxalic acid at pH 4.5 containing either 5 mM 15-crown-5 (1,4,7,10,13-pentaoxacyclopentadecane) or 0.5 mM and 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) as eluent, excellently simultaneous separation of these cations was achieved in 21 min. The proposed IC-IPD was successfully applied to the determination of major cations in natural water samples.     

微波消解样品-离子色谱法测定卷烟纸中钠、钾、镁、钙的含量

提出了离子色谱法同时测定卷烟纸中钠、钾、镁和钙含量的方法。卷烟纸试样经硝酸-过氧化氢-氢氟酸微波消解,以IonPac CS16阳离子交换柱为固定相,用0.027 mol.L-1甲烷磺酸溶液作流动相。钠、钾、镁和钙4种元素在30 min内可完全分离;各离子的检出限(3S/N)分别为13,15,8.1,97 mg.L-1。方法的加标回收率在100.9%～108.8%之间,测定值的相对标准偏差(n=5)在0.87%～3.4%之间。     

离子色谱法测定饲料中氯化胆碱和三甲胺的含量

建立了离子色谱法测定饲料中氯化胆碱含量及鉴别饲料中氯化胆碱及掺假物三甲胺的方法。选用IonPac CS12阳离子交换色谱柱(250 mm×4 mm i.d.)和8.5 mmol/L H2SO4淋洗液,抑制型电导检测,在16 min内分离测定了包括胆碱和三甲胺在内的8种阳离子。胆碱和三甲胺的最小检出限分别为0.1 mg/L和0.05 mg/L。方法回收率为99.25%~102.5%。该方法具有灵敏度高、选择性强、操作简单等优点。     

High-resolution determination of H+ by ion chromatography. Application to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain.

An ion chromatographic (IC) method was developed for the high-resolution determination of a sample's free hydrogen ion concentration (H+). Highly purified lithium dodecyl sulfate was used as the stationary phase, a slightly acidified aqueous LiCl solution was used as the mobile phase and conductivity was used for analyte detection. An electrical double layer (EDL) containing H+ was established on the stationary phase by using a slightly acidified electrolyte solution as the eluent. H+ in the EDL protonated any weak acid groups (i.e., silanols) on the stationary phase so that H+ from the sample could be retained/separated purely by dodecyl sulfate. The optimum molar ratio of H+:Li+ in the EDL for this IC system was obtained by using an aqueous solution containing 40.0 mM LiCl and 0.07 mM H2SO4 as the eluent. After separation, H+ was detected by direct conductimetric measurement. An H+ detection limit of better than 8.2 x 10(-6) M was obtained from the analysis of standard aqueous H2SO4 solutions. Other monovalent cations could also be separated with this method, giving detection limits of 7.4 x 10(-5), 4.3 x 10(-5) and 4.2 x 10(-5) M for Na+, NH4+ and K+, respectively. The method was applied to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain. The results obtained showed a significant improvement in reproducibility when compared with those from a conventional pH-meter. Acid rain samples with a pH < 5 could be analyzed with this IC system.     

Simultaneous ion-exclusion chromatography and cation-exchange chromatography of anions and cations in environmental water samples on a weakly acidic cation-exchange resin by elution with pyridine-2,6-dicarboxylic acid

A non-suppressed conductivity detection ion chromatographic method using a weakly acidic cation-exchange column (Tosoh TSKgel OApak-A) was developed for the simultaneous separation and determination of common inorganic anions (Cl-, NO3- and SO4(2-)) and cations (Na+, NH4+, K+, Mg2+ and Ca2+). A satisfactory separation of these anions and cations on the weakly acidic cation-exchange column was achieved in 25 min by elution with a mixture of 1.6 mmol L-1 pyridine-2,6-dicarboxylic acid and 8.0 mmol L-1 18-crown-6 at flow rate of 1.0 mL min-1. On this weakly acidic cation-exchange resin, anions were retained by an ion-exclusion mechanism and cations by a cation-exchange mechanism. The linear range of the peak area calibration curves for all analytes were up to two orders of magnitude. The detection limits calculated at S/N = 3 ranged from 0.25 to 1.9 mumol L-1 for anions and cations. The ion-exclusion chromatography-cation-exchange chromatography method developed in this work was successfully applied to the simultaneous determination of major inorganic anions and cations in rainwater, tap water and snow water samples.     

Monolithic octadecylsilyl-silica gel column for the high-speed ion chromatographic determination of acidity

A monolithic ODS-silica gel column modified by saturating it with lithium dodecylsulfate (Li-DS) was used to demonstrate the high-speed separation of H+ from other mono- and divalent cations, such as Na+, NH4+, K+, Mg2+ and Ca2+ using ion chromatography (IC). Using a 5 mM EDTA-2K solution containing 0.10 mM Li-DS (pH 4.80) as eluent, H+ was eluted with a sharp and symmetrical peak within 1.0 min before other cations at a flow-rate of 1.5 ml min(-1). The rapid elution of H+ and its conductimetric detection could be attributed to the presence of EDTA (HY2-), which can convert H+ ions as anions. i.e. H(+) + H2Y(2-) --> H3Y(-). The acidity of rainwater and deionized water samples was determined using this IC system with satisfactory results.     

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.     

Determination of lithium in wines by ion chromatography

Lithium ion can be added as a denaturing agent to wines unsuitable for consumption. Accuracy of flame atomic emission spectroscopy with direct nebulization, which is commonly adopted for discovering illegal use of denatured wines, was found to be compromised by Na+, K+, NH4+, Mg2+, Ca2+ and ethanol contained in wine. Ion chromatography (IC) was tested in order to propose an alternative method for legal controls. Experimental design was used to investigate the influence on the accuracy of the determination of Li+ at ppb levels, of Na+ and ethanol content of wine and of fluctuations of eluent flow-rate and composition. It turned out that IC quantification of Li+ can be affected by eluent parameters rather than by wine composition. Since the former can be maintained under the operators control, while the latter cannot, IC was judged preferable to AES for legal controls of Li+ in wines.     

Simultaneous ion chromatographic separation of anions and cations on poly(aspartic acid) functionalized silica

Poly(aspartic acid)-silica (PolyCAT A), originally designed for the cation-exchange chromatography of proteins, is proposed for the simultaneous ion chromatographic separation of inorganic anions and cations. This is possible owing to the zwitterion-exchange properties of this stationary phase, which are attributed to the presence of both protonated aminopropyl and dissociated carboxylic groups in poly(aspartic acid) attached to the silica. The retention of alkali metal (Li+, Na+, K+), alkaline earth metal (Mg2+, Ca2+), ammonium and inorganic anions (Cl-, H2PO4-, Br-, NO2-, I-, IO3-, NO3-, ClO4-, SCN-) was tested in aqueous solutions of sulfuric, perchloric, sulfosalicylic, citric, oxalic, maleic and aspartic acids with conductimetric detection. The effect of eluent pH, together with the concentration and characteristics of the eluting ions, were studied. Under optimum conditions (0.3 mmol dm(-3) H2SO4-0.2 mmol dm(-3) Li2SO4 eluent), the simultaneous separation of three anions (Cl-, H2PO4-, NO3-) and four cations (Na+, K+, Mg2+, Ca2+), on a PolyCAT A column (200 x 4.6 mm id, 5 microm film thickness) was achieved in 9 min.     

Use of mobile phase 18-crown-6 to improve peak resolution between mono- and divalent metal and amine cations in ion chromatography

It is difficult to quantify NH4+ by ion chromatography in the presence of high concentrations of Na+ due to peak overlap. The Dionex IonPac CS15 column, which contains phosphonate, carboxylate, and 18-crown-6 functional groups, was originally developed to overcome this problem. We have found that the addition of 18-crown-6 to the eluent promotes improved peak resolution between Na+ and NH4+ even at concentrations as high as 60,000 to 1 using this column. Its use also improves the separation of alkali and alkaline earth metal and amine cations. Mobile phase 18-crown-6 increased the retention times of CH3NH3+, NH4+, and K+, and decreased the retention time of Sr2+. The retention times of Li+, Na+, Mg2+, Ca2+, (CH3)2NH2+, and (CH3)3NH+ were not affected. This method makes possible the direct analysis of ammonia from nitrogenase, the enzyme responsible for biological nitrogen fixation. The resolution of the NH4+ peak from the Na+ and Mg2+ peaks improved from zero resolution to values of 6.19 and 5.65, respectively. This technique considerably reduces the analysis time of NH4+ in the presence of high concentrations of Mg2+ and Na+ over traditional indophenol measurements.     

芳香酸淋洗液的单柱阳离子色谱法测定碱金属,铵离子和烷基胺

研究了邻苯二甲酸、苯甲酸和对羟基苯甲酸３种芳香酸分别做淋洗液的单柱阳离子色谱法分离测定Ｌｉ＋、Ｎａ＋、ＮＨ４＋、Ｋ＋、甲胺、乙胺和正丙胺７种物质。３种芳香酸做淋洗液均可将７种物质分离开，且分离结果差异不大。在淋洗液浓度相同的条件下，邻苯二甲酸做淋洗液测定的检出限较低。选择３．０ ｍｍｏｌ／Ｌ邻苯二甲酸做淋洗液测得了上述７种物质的检出限和线性范围，并进行了叶面肥试样分析，７种物质的加标回收率在９６．４％～９８．６％之间。     

Simultaneous separation of nine metal ions and ammonium with nonaqueous capillary electrophoresis

A simple and fast method for simultaneous separation of nine metal cations Ni2+, Cu2+, Co2+, Zn2+ Cd2+, K+, Na+, Mg2+ and Ca2+, and NH4+ in methanol is reported. The optimization for separation these 10 cations was achieved by using 0.5% acetic acid and 10 mM imidazole as electrolyte. The effects of water and ionic strength in the sample are discussed. The sensitive detection of transition metal ions was accomplished at 191 nm. The optimized method demonstrated high efficiency and good reproducibility, and was applied successfully to the qualitative and quantitative determination of transition metal ions in water samples, chemical reagents, oral zinc gluconate solution and human plasma.     

Analysis of size-classified ice crystals by capillary electrophoresis

In order to analyse the main inorganic cations (NH4+, K+, Na+, Ca2+, Mg2+) and anions (Cl-, NO3-, SO4(2-)) as well as carboxylic and dicarboxylic acids in ice crystals by capillary electrophoresis, electrolyte systems were developed and optimised with respect to limits of detection, resolution, reproducibility and analysis time. We applied indirect UV detection, which enables the simultaneous detection of multiple components. Salicylic acid and 4-methylaminophenolsulfate were used as UV-active co-ions for analysis of anions and cations, respectively. The special features of these systems were low limits of detection in the range 0.3-0.9 micromol L(-1), i.e. absolute limits of detection were in the fmol range, and short analyses times. Separations of cations as well as anions including carboxylic and dicarboxylic acids were completed within 4 min allowing a high sample throughput. Furthermore, the applicability of the newly developed electrolyte systems was demonstrated by comparative analyses with ion chromatography and by first field experimental studies.     

Determination of total acidity and of divalent cations by ion chromatography with n-hexadecylphosphocholine as the stationary phase

An ion chromatographic (IC) method is reported for simultaneous determination of total acidity (H+), Ba2+, Ca2+, and Mg2+ in aqueous samples. A standard ODS silica column modified by coating with n-hexadecylphosphocholine was used as the separation column. Water alone was used as the eluent, with conductivity detection of the sample ions. An excess of sodium iodide was added to each sample so that both H+ and divalent cations were always eluted with iodide as the counterion. The elution order was Ba2+, Mg2+, Ca2+, and H+ with H+ being eluted much later than the divalent cations. Acetic acid and several other weak acids could also be separated because all the protons were transposed from acetic acid (HAc) to HI by the sodium iodide. Detection limits for 100 microl injection, S/N=3 were in the low micromolar range for the divalent cations and approximately 0.3 mM for H+/I-. This method was used successfully for simultaneous determination of total acidity, magnesium and calcium in HCl-type of hot-spring water.