固相萃取-离子色谱法测定地下水中痕量高氯酸根离子

建立了测定地下水中痕量高氯酸根（ClO~4）的固相萃取-离子色谱(SPE-IC)分析方法。0.7 L水样经预处理降低主要干扰离子Cl~、CO2~3和SO2~4的干扰后,使用Cleanert PWAX弱阴离子交换固相萃取小柱对地下水中痕量(μg/L级)的ClO~4进行富集,用6 mL 1%NaOH溶液洗脱,富集液经0.45 μm水膜过滤后,用IonPac AS20阴离子分离柱、50 μL进样环、40 mmol/L KOH溶液淋洗、抑制电导检测分离分析。结果表明,地下水样品中ClO~4的方法检出限和测定下限分别为0.15 μg/L和0.60 μg/L,进样质量浓度在1～15 μg/L范围内有很好的线性关系,线性相关系数为0.9992,回收率为99.7%～100.5%;该方法经济有效,可用于地下水中痕量ClO~4的检测。利用该方法测定了哈尔滨周边部分地区地下水中ClO~4浓度,检测结果与离子色谱-质谱联用法的检测结果的相对误差为1.85%～9.24%。     

High-capacity cation-exchange column for enhanced resolution of adjacent peaks of cations in ion chromatography

One of the advantages of ion chromatography [Anal Chem. 47 (1975) 1801] as compared to other analytical techniques is that several ions may be analyzed simultaneously. One of the most important contributions of cation-exchange chromatography is its sensitivity to ammonium ion, which is difficult to analyze by other techniques [J. Weiss, in: E.L. Johnson (Ed.), Handbook of Ion Chromatography, Dionex, Sunnyvale, CA, USA]. The determination of low concentrations of ammonium ion in the presence of high concentrations of sodium poses a challenge in cation-exchange chromatography [J. Weiss, Ion Chromatography, VCH, 2nd Edition, Weinheim, 1995], as both cations have similar selectivities for the common stationary phases containing either sulfonate or carboxylate functional groups. The task was to develop a new cation-exchange stationary phase (for diverse concentration ratios of adjacent peaks) to overcome limitations experienced in previous trails. Various cation-exchange capacities and column body formats were investigated to optimize this application and others. The advantages and disadvantages of two carboxylic acid columns of different cation-exchange capacities and different column formats will be discussed.     

Ion chromatography coupled with fluorescence/UV detector: A comprehensive review of its applications in pesticides and pharmaceutical drug analysis

Ion chromatography (IC) is a well-known technique for trace determination of inorganic ions and small organic acids. Recently, it has also appeared as a promising alternative to reverse phase chromatography for the determination of polar pesticides and pharmaceutical drugs in various sample matrices. Therefore, this study aims to provide a comprehensive overview of the application of IC coupled to fluorescence (FLD) or UV detector for the determination of pesticides and pharmaceutical drugs in samples from all walks of life. Apart from advantages and limitations, a short comparison of IC-FLD/UV with other techniques especially reverse-phase chromatography was drawn to envision future research efforts in this direction. Finally, several related areas such as IC hyphenation with different detectors (spectroscopic and spectrometer), miniaturization, automation, green chemistry, mobile phase, column, sample preparation, etc., were discussed to highlight its application for the determination of a wide range of analytes in the complex sample matrix.     

Determination of inorganic cations in brine solutions by ion chromatography

The method for analysis of inorganic cations in brine solutions was developed. Ion chromatography is a well-established and accepted technique in the determination of a variety of inorganic ions. However, there are significant complications when ion chromatography is used to determine trace concentrations of inorganic ions in brine matrices. The brine solution in our study was made to simulate the solution from the Waste Isolation Pilot Plant. Instrumental parameters such as eluent composition, flow-rates, and sample loop volumes were investigated to arrive at the optimum condition for the determination of the cations with minimal dilution. Separation was carried out in a Dionex CG12A/CS12A with 8.25 mM H2SO4 as eluent at 1.2 ml/min flow-rate. Our results indicated that ion chromatography is an accurate and a good alternative method for the analysis of cations in brine solution.     

离子色谱-抑制电导法分别测定海水中阴离子和阳离子

采用离子交换-抑制电导法测定海水中阴、阳离子。采用抑制电导可以降低淋洗液的背景电导,又可以增加被测离子的电导值,改善信噪比。采用的电化学自身再生抑制器,由连续电解水产生抑制淋洗液所需要的H^＋或者OH^-,加上电场引力,能用于高客量分离柱所用的淋洗液浓度和梯度淋洗。在试验条件下,利用阴离子和阳离子分离柱,配合抑制电导检测,可以同时分离和测定海水中7种阴离子和6种阳离子。且都可以得到很好的线性和较低的检出限。     

Applications of ion chromatography in cane sugar research and process problems

Ion chromatography (IC) offers the sugar technologist a simple, reliable technique for the simultaneous separation and determination of inorganic and organic ions in complex process mixtures. Identification and measurement of ions present in sugar liquors are important factors in understanding and maximising sugar recovery. Choice of IC column packing, eluent composition and pH, and detection mode (suppressed and non-suppressed) are shown to be useful variables when analysing sugar factory products, especially the multivalent ions such as phosphate and organic acids (aconitic and oxalic acid). The IC methods show good agreement with conventional analysis methods (potentiometric titration, atomic emission and absorption). IC also produced excellent repeatability and recovery from these matrices. Examples of the application of IC analysis in applied sugar research and processing problems include clarification studies, degradation of molasses, sugar solution colour removal and factory process problems.     

离子色谱法测定农村饮用水中阴离子

采用离子色谱法测定农村饮用水中F-、Cl-、NO2-、Br-、NO3-和SO42-等6种阴离子的含量。水样经Ion Pac AG19保护柱及Ion Pac AS19分离柱分离,以20.00mmol·L-1氢氧化钾溶液为淋洗液,采用抑制电导器检测。F-、NO2-和Br-在4mg·L-1以内,Cl-、NO3-和SO42-在40mg·L-1以内呈线性关系,检出限(2S/N)在0.002～0.012mg·L-1之间。方法用于水样中6种阴离子的测定,加标回收率在98.0%～101.3%之间,相对标准偏差(n=6)在0.83%～2.7%之间。     

高温水解–离子色谱法测定八氧化三铀中的氟和氯

建立了高温水解–离子色谱法测定八氧化三铀中氟和氯含量的方法。对影响高温水解的因素进行了试验研究,水解温度为1 050℃,水浴温度为(85±1)℃,氩气流量为600 mL/min,水解时间为1 h。选用Ion Pac AG11–HC(50 mm×4 mm)阴离子保护柱和Ion Pac AS11–HC(250 mm×4 mm)阴离子分析柱对样品进行分离,以氢氧化钾溶液等度淋洗。在0~5.00μg/mL范围内,氟和氯均有良好的线性,相关系数(r~2)分别为0.999 9,0.999 4;检出限分别为3,4μg/g。氟和氯测定结果的相对标准偏差分别为4.72%,3.23%(n=6),加标回收率分别为97%~101%,95%~99%。该法操作简便、快速,适用于八氧化三铀中氟和氯的检测。     

Determination of nickel in human urine by ion chromatography with series bulk acoustic wave detection

By using ion chromatography with series bulk acoustic wave detection, a method for the determination of nickel at microgram per liter levels in urine has been developed. The highly sensitive response of series bulk acoustic wave (SBAW) detection has been combined with the selectivity of ion chromatography and hence sensitivity and precision have been improved. The detection and determination limits of the method for nickel are 0.4 and 2.0 ng ml(-1), respectively. For the IC analysis, the analytical column is a Shim-pack IC C1 column and the mobile phase is 4.5 mM tartaric acid solution. The method allows the determination of nickel in the presence of some ions commonly co-occurring with it. Urine samples from individuals with no occupational exposure to nickel were analyseded successfully.     

离子色谱法测定乳品中硫氰酸钠含量

采用离子色谱法测定乳品中硫氰酸钠的含量。样品用5 mL乙腈沉淀蛋白质,上清液过C18柱净化,所得的产物采用离子色谱法测定,外标法定量。结果表明,通过流动相以及前处理方法的改进,硫氰酸钠质量浓度在0.10~4.00 mg/L范围内与色谱峰面积呈良好的线性,相关系数r2=1,方法的检出限为0.01 mg/L。在牛奶样品中加入硫氰酸钠标准溶液进行回收试验,测得回收率为95.0%~101.0%,测定结果的相对标准准偏差为1.8%~2.8%(n=7)。该方法操作简便,能有效避免假阳性的发生,测定结果准确,适合于乳品中硫氰酸钠的检测。     

Ion chromatographic determination of trace iodate, chlorite, chlorate, bromide, bromate and nitrite in drinking water using suppressed conductivity detection and visible detection

An ion chromatography method for the simultaneous determination of trace iodate, chlorite, chlorate, bromide, bromate and nitrite in drinking water has been developed using an anion-exchange column and the suppressed conductivity detector, followed by post-column addition of reagent to enhance visible absorbance detection of ions. A high capacity anion exchange Ion Pac9-HC column (250 mm x 4 mm I.D.) was used. Eight millimole per liter sodium carbonate was used as eluent, an auto-suppression external water mode was selected, 0.5 g/l o-dianisidine.2HCl (ODA)+4.5 g/l KBr+25% methanel+5.6% nitric acid was used as post-column reagent. The post-column reaction (PCR) temperature was at 60 degrees C, and the visible absorbance detected wavelength at 450 nm. The sample's pH and coexist anions had no influence on determination. The method enjoyed a wide linear range and a good linear correlation coefficient (r>0.999). The method detection limits were between 0.023 and 2.0 microg/l. The average recoveries ranged from 87.5 to 110.0%, and the relative standard deviations (RSD) were in the range of 1.1-4.6%. The analytical results by the method of post-column addition of reagent to enhance visible absorbance detection of anions was compared with that of the suppressed conductivity detection, and the former was proved to be better in sensitivity and selectivity. The results showed that this method was accurate, sensitive and might be good for application and suitable for trace analysis at the level of mug/l.     

Separation of Organic Acids in Plant Tissue by HPLC with a Twin Phase,Ion Exchange and Reverse Phase,Column

Abstract

No single isocratic chromatographic technique allows the complete separation of common organic aliphatic and alicyclic acids of plants. In order to obtain a better isocratic separation with a single HPLC method we combined in one chromatography assay the Ion Exchange and Reverse Phase technics in building a twin phase column. The first attempts are promising. This double chromatography based on the polarity of molecule (Reverse Phase) and on its acidic characteristics (Ion Exchange) has the advantages of both methods and allows good separations of the acids.     

Separation, identification, and quantification of selected withanolides in plant extracts of Withania somnifera by HPLC-UV(DAD)--positive ion electrospray ionisation-mass spectrometry

This paper describes a method for separation, identification, and quantification of selected withanolides in Withania somnifera plant extracts by HPLC-UV(DAD)-Mass Spectrometry (HPLC-MS). Withaferin-A (WS-3), 12-deoxywithastramonolide (WS-12DS), Withanolide A (WS-1), and Withanone (WS-2) were used as external standards. The compounds were isolated from Withania somnifera by repeated column chromatography of the root extract and their identity was established by 1H- and 13C-NMR and mass spectral data. The compounds were chromatographed on a Merck (250 x 4.6 mm ID, 5 microm) column and analyzed by Electrospray Ionization on a mass spectrometer in Selected Ion Mode (SIM). For quantification, [M + Na]+ ions were monitored. Linear calibration curves were obtained in the concentration range of 1.50 microg/mL to 6.5 microg/mL. The method was applied successfully to the detection and quantification of the said withanolides in a number of samples.     

二维离子色谱法测定精己二酸中痕量硝酸根离子

建立二维离子色谱法测定精己二酸中痕量硝酸根离子含量的方法。第一维采用去离子水作为流动相,经过Ion Pac ICE–AS1色谱柱将精己二酸中的硝酸根离子和己二酸进行预分离,分离出来的硝酸根富集于Ion Pac TAC–ULP1浓缩柱上。以淋洗液发生器产生的不同质量浓度的氢氧化钾溶液作为淋洗液,将富集柱上的硝酸根淋洗下来,经第二维Ion Pac AS17–C色谱柱进行分离,以抑制型电导检测器测定硝酸根离子的含量。精己二酸中硝酸根离子的质量浓度在2.0~50.0μg/L范围内与其色谱峰面积呈良好线性,线性相关系数r20.999,检出限为0.10μg/L,测定结果的相对标准偏差小于1.5%(n=7),加标回收率为98.0%~105.0%。该方法操作简单,灵敏度、准确度高,选择性好,能够准确测定精己二酸中痕量硝酸根离子的含量。     

A detection method for unified chromatography: Ion mobility monitoring

Ion mobility monitoring has been used for detection in gas, supercritical fluid, and liquid chromatography, illustrating its potential as a method of detection for unified chromatography. Applications presented include GC-IMD of dioxins in fly ash, SFC-IMD of vitamin E, and HPLC-IMD of alkylamines. Ion mobility spectra of several mixed supercritical fluid mobile phases are also presented. Use of methanol, acetonitrile, and dichloromethane as modifiers of supercritical carbon dioxide, and use of supercritical dichlorodifluoromethane and chlorodifluoromethane as mobile phases had little effect on the reactant ion pattern at the flow rates and concentrations used in this study. Only when acetone was used as a modifier of carbon dioxide did the positive reactant ions change significantly. No effect of modifiers or mobile phase was observed for the negative reactant ions.     

气相色谱法测定痕量氟方法的研究

气相色谱法测定有机硅化合物中的痕量氟是60年代末发展起来的,1967年Bock和Semmer^[1]用三乙基氯硅烷等有机硅化合物萃取,用半饱和NaHCO₃反萃测定氟,并建议可用GC法直接测定三乙基氟硅烷,1968年Fressen等^[2]用气相色谱法测定氟,近20年来,气相色谱法测定氟在环境监测、卫生防疫等方面得到应用^[3,4]。     

Invetigations into the use of an auxiliary metal ion for indirect amperometri detection

Summary A method for determination of metal ions subsequent to separation by ion chromatography has previously been developed. The method is based on Indirect Amperometric Detection whereby the decrease in the oxidation current, due to a dithiocarbamate ligand added post column, is monitored. Upon elution from the chromatographic column the metal ions are complexed by the ligand. As the complexes formed are electroinactive at the applied potential, the background current decreases according to the metal ion concentration. The method developed in this work involves addition to the reagent of Zn(II) as a auxiliary metal ion to displace the analyte metals from the chromatographic eluent ligand complexes after separation. Sodium bis(2-hydroxy-ethyl) dithiocarbamate was used as the postcolumn derivatising reagent. The addition of Zn(II) to the reagent causes some unforeseen behaviour in the chromatographic system.     

Chloride attachment negative-ion mass spectra of sugars by combined liquid chromatography and atmospheric pressure chemical ionization mass spectrometry

A method has been developed for the rapid determination of sugars, including molecular weight measurements, using high-performance liquid chromatography coupled with negative-ion, atmospheric-pressure chemical-ionization mass spectrometry. The chromatography was carried out on a 250 x 4 mm I.D. column packed with 7 microns NH2-silica. The mobile phase consisted of a high percentage of methanol or acetonitrile with a small amount of chloroform. During the mass spectrometry, a strong base is formed from the polar solvent molecules by corona discharge, followed by ion-molecule reactions in the chemical ionization ion source (e.g. the methoxy anion is formed from methanol). This strong base reacts with the chloroform, generating chloride ions, which in turn react with the neutral sugar molecules as they elute from the chromatograph. The chloride ion and sugar interactions yield chloride-attachment ions, which are further stabilized by successive collisions. In this method, authentic monosaccharides and some oligosaccharides show dominant quasi-molecular ions, [M + Cl]-, with little fragmentation, and its particularly useful for the molecular weight determination of sugars.     

离子色谱法分析金属离子的研究进展

综述了离子色谱法(IC)分析金属离子的研究进展,对目前应用于分析金属离子的阳离子交换IC、阴离子交换IC和螯合离子色谱进行了评述。阳离子交换IC是IC分析金属离子的主要形式,固定相为强酸(磺酸)型阳离子交换剂和弱酸(羧酸)型阳离子交换剂,结合适当的检测方法,阳离子交换IC可以测定碱金属、碱土金属、过渡金属、稀土离子、铵离子及低相对分子质量的有机胺类分子等。阴离子交换IC可以分析碱土金属、过渡金属、稀土离子等,对金属离子的分析具有更好的选择性,并可以实现金属离子和无机阴离子的同时测定。螯合离子色谱可以对复杂基体中的痕量金属离子进行测定。引用文献125篇。     

Determination of REEs distribution in monazite and xenotime minerals by ion chromatography and ICP-AES

Ion chromatographic techniques were investigated for the separation and the quantitative determination of some rare earth elements (REEs) in monazite and xenotime minerals. The influences of selected eluents containing complexing acids including oxalic and alpha-hydroxy isobutyric acid (alpha-HIBA) on the retention and hence the separation efficiency of REEs was studied. Different variables affecting the separation of different REEs such as pH, type, and concentration of the mobile phase were investigated. Gradient elution, using an advanced gradient pump, was controlled automatically by the Dionex AI-450 computer software. Separation of REEs was carried out using an Ion Pac CS5A column followed by a post column derivatization reaction with 4-(2-pyridylazo)resorcinol (PAR) and UV-VIS spectrophotometric detection. Mineral dissolution was carried out using sulfuric acid. A comparative evaluation of REE distribution in monazite and xenotime minerals using both ion chromatography (IC) and inductively coupled plasma atomic emission spectrometric (ICP-AES) techniques was carried out.