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《Analytical letters》2012,45(9):2123-2143
Abstract

Differential double-layer capacitance measurements applied to the silver-aqueous interface may serve as the basis of detection for surface-active ions in ion chromatography. There is a caveat to this approach, though, and that is that the electrode is subject to gradual fouling due to the accumulation of adsorbed matter. We report here on the incorporation of potential pulsing sequences to counter this damaging effect. Two approaches have been taken: 1) inclusion of a periodic potential cleaning pulse in the conventional, fixed-potential double-layer capacitance measurement scheme, and 2) utilization of a potential-pulse/coulometric measurement technique. the potential-pulse/coulometric procedure entails measurement of the change in charge required to charge the electrical double layer in response to specific adsorption of analyte. Its response-concentration behavior is similar to that observed for differential capacitance detection. the use of a combined, dual-potential (sequential) capacitive/amperometric detection scheme that provides unique complementation to either amperometric or capacitance detection is also discussed.  相似文献   

3.
离子色谱中的安培检测方法及其应用   总被引:1,自引:0,他引:1  
于泓  牟世芬 《化学通报》2007,70(7):483-488
介绍了离子色谱中的安培检测方法(包括恒电位安培检测法、脉冲安培检测法和积分脉冲安培检测法)的原理和应用。脉冲安培检测法与高效阴离子交换色谱结合(HPAEC-PAD)是一种新的分析糖类化合物的方法;积分脉冲安培检测法与高效阴离子交换色谱结合(HPAEC-IPAD)是一种新的氨基酸分析方法。  相似文献   

4.
The formation of gas bubbles is a key issue for nuclear fuel behaviour. The first measurements of xenon during a depth profile in irradiated nuclear fuel evidenced some peaks over a non-zero baseline. In comparison with EPMA mappings of xenon and SEM image of the sputtered surface, it is proven that the peaks correspond to bubbles while the baseline corresponds to xenon included in the UO2 matrix.  相似文献   

5.
Microchip electrophoresis is emerging as a highly promising method due to its portability and fast analysis with a minimum number of analytes. In this review, recent developments in microchip electrophoresis were described with discussions on the structures, materials, processing technologies, surface modification, experimental methods, and applications in ion detection. The existing issues and prospects of future studies were discussed as well.  相似文献   

6.
抑制电导检测-离子色谱法测定面粉中的溴酸盐   总被引:3,自引:1,他引:3  
采用离子色谱-抑制电导检测方法分离测定面粉中的溴酸盐.采用IonPacAS19阴离子色谱柱(Dionex),以20.0mmol/LKOH溶液作流动相,方法BrO3^-检出限为0.015mg/L(进样体积50μL,S/N=3),标准曲线的线性范围为0.04~2.0mg/L(r=0.999 9),相对标准偏差为2.5%(n=8).用本方法测定面粉样品,加标回收率在82%~105%之间.实验表明,本方法准确、灵敏、重复性好,结果令人满意.  相似文献   

7.
不完全抑制电导检测离子色谱法测定饮料中的苹果酸   总被引:2,自引:0,他引:2  
朱岩  徐素君  王素芬 《分析化学》1999,27(9):1050-1053
采用一种抑制型离子色谱检测技术--不完全抑制电导检测,以0.75mmol/LNa2SO4+NaOH(pH=11.5)为淋洗液对弱酸根离子如苹果酸、酒石酸等进行了测定,得到苹果酸、酒石酸的检测限分别为1.31mg/L、3.04mg/L;在200mg/L以下相关系数分别为0.9998、0.9999;;各离子峰高的相对标准偏差(RSD)分别为0.57%、1.60%。上率为97.7 ̄104%。常见的强酸离  相似文献   

8.
离子色谱-抑制电导法分别测定海水中阴离子和阳离子   总被引:3,自引:0,他引:3  
以氢氧化钾为流动相,阴离子交换分离,抑制电导检测,可以同时分离F-、Cl-、Br-、NO3-、SO42-、PO43-I、-等海水中的常见阴离子,利用梯度淋洗可以使以上各种离子在其最佳保留时间和最佳峰形条件下出峰。以8 mmol/L H2SO4为淋洗液,阳离子交换分离,抑制电导检测,可以同时分离测定海水中的Na 、K 、Mg2 、Ca2 、Sr2 和Ba2 。在所采用的色谱条件下各阴阳离子均可以得到很好的线性和很低的检出限。  相似文献   

9.
Ion implantation is a well-known standard procedure in electronic device technology for precise and controlled introduction of dopants into silicon. However, damage caused by implantation acts as effective gettering zones, collecting unwanted metal impurities. This effect can be applied for proximity gettering reducing the concentration of impurities in the active device region. In this study the consequences of high-energy ion implantation into silicon and of subsequent annealing were analysed by means of secondary ion mass spectrometry (SIMS). Depth profiles were recorded of such impurities as copper, oxygen and carbon to obtain information about their gettering behaviour. The differences in impurities gettering behaviour were studied as a function of the implanted ions, P and Si, of the implantation dose and annealing time at T=900°C. Besides impurities gettering at the mean projected range (Rp) of implanted ions, Rp-effect, defects at around half of the projected ion range, Rp/2-effect, and even in some cases beyond Rp, trans-Rp-effect, have also been found to be effective in gettering of material impurities.  相似文献   

10.
离子色谱-积分脉冲安培检测法测定大蒜多糖的单糖组成   总被引:2,自引:1,他引:2  
采用氨基酸分离柱(Amino PAC PA10,2×250 mm),用10.0 mmol/L NaOH溶液作为流动相,以Au为工作电极,Ag/AgCl为参比电极的脉冲积分安培离子色谱法,分离检测了大蒜多糖水解产生的单糖成分及相对含量。实验结果表明,大蒜多糖中含有半乳糖、葡萄糖、甘露醇和果糖,检出限在0.3~6μg/L范围,样品加标回收率为95%~112%。该法具有灵敏度高、精密度好、分离效果好和样品不需要衍生处理的优点,适用于各种植物多糖的单糖组成分析。  相似文献   

11.
采用离子交换色谱-积分脉冲安培检测法分离测定了鸡精、酱油、沙拉中的葡萄糖、果糖、蔗糖、乳糖和麦芽糖,研究了5种糖在阴离子交换色谱中的保留行为。采用水和0.2 mol.L-1氢氧化钠为淋洗液梯度洗脱,流速为0.5 mL.min-1,CarboPacTMPA 10为分离柱,金电极为工作电极,Ag/AgCl电极为参比电极,积分脉冲安培检测法一次进样测定鸡精、酱油、沙拉中的5种糖的含量。各组分在测试条件下分离效果较好。5种糖类在0.5~10.0 mg.L-1质量浓度范围内与其峰面积呈线性关系。5种糖的检出限(3S/N)为0.8~2.5μg.L-1,该方法用于食品中糖类的测定,5种糖的回收率为91.1%~104.5%。  相似文献   

12.
除草剂2-甲基-4-氯苯氧乙酸的离子色谱分离荧光检测   总被引:2,自引:0,他引:2  
介绍了离子色谱荧光检测除草剂2_甲基_4_氯苯氧乙酸 (简称2甲4氯 )的方法 ,2甲4氯溶液在流速为1.5mL·min -1,淋洗液为0.1mol·L -1Na2CO3-0.1mol·L -1NaHCO3 混合溶液 ,荧光检测器的激发波长为284.9nm ,发射波长为314.5nm的条件下 ,能得到较好的分离和检测 ;在该条件下 ,2甲4氯具有良好的线性关系和重复性 ,检出限为0.093mg·L -1,对土壤样品进行检测 ,回收率98 %~103 %。  相似文献   

13.
Automated quantitative comparison of depth-profiles recorded by SIMS based on a fuzzy difference measure has been used to characterize Sb and B implantation profiles in a marker experiment to study the diffusion of As in silicon. The variations of the concentration (intensity) measurements are described by a fuzzy set that is specified by smoothing the data with a polynomial digital filter. For each depth an individual spread as the size of variation is defined. Applications of the method enabled the influence of As-concentration and of annealing conditions on the implantation profiles of Sb and B to be quantified.  相似文献   

14.
《Analytical letters》2012,45(5):922-931
An investigation into the determination of four imidazolium ionic liquid cations by ion chromatography using a carboxyl acid cation exchange column and direct conductivity detection was carried out. This research has developed a simple, selective, and accurate ion chromatographic method for separation of imidazolium ionic liquid cations. Detection limits (S/N = 3) for the cations were 3.2–24.3 mg/L. Relative standard deviations (RSD, n = 5) for peak areas were less than 1.6%. The method has been successfully applied to the determination of two ionic liquids synthesized by organic chemistry lab.  相似文献   

15.
The design philosophy and implementation of an ultra high vacuum (UHV), PC controlled, automated in situ fracture stage for a surface analysis system is described. ToF‐SIMS spectra are shown to illustrate the improvement in spectral quality obtained from micro‐compact tension (CT) tests of polymer matrix fracture surfaces produced using the fracture stage in UHV compared to those obtained from a sample tested at air. This system is flexible in that by changing the capacity of the load cell it is possible to reduce or increase maximum loads as the specimen type and material demands. The stage has been designed with instrumental flexibility in mind, utilising commercial SEM‐stub type sample mounts, and can thus be used for AES/SAM and XPS investigations, as well as ToF‐SIMS analysis, in the authors' laboratory. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

16.
采用高效阴离子色谱分离-积分脉冲安培法测定地质样品中总碘的含量。采用碳酸钠-氧化锌烧结方法分解样品,烧结温度为700℃。以亚硫酸钠溶液作为还原剂,以氢氧化钠溶液为淋洗液,在IonPac AG11和IonPac AS11阴离子交换柱上分离。碘的质量分数在0.16~50μg·g-1范围内与其峰高呈线性关系,检出限(3s)为0.08μg·g-1。方法应用于国家标准物质的测定,测定值与认定值相符,测定值的相对标准偏差(n=12)在2.7%~7.3%之间。  相似文献   

17.
 Methodologies based on secondary ion mass spectrometry (SIMS) for isotopic measurements in nuclear forensic applications relevant to the age determination of Pu particles and isotopic composition of oxygen for geolocation assignment are described. For the age determination of Pu particles, a relative sensitivity factor (RSF) to correct for the different ionisation efficiencies of U and Pu, was obtained by analysing standard Pu materials with known ages. An RSF of 2.41±0.05 was obtained for PuO2 from measurements on samples with different Pu/U ratios. In a sample of known origin, using this RSF value, the age calculated from the 238Pu/234U and 240Pu/236U ratios agreed well with the reported age of 2.3 years. For geolocation assignment, a new approach based on the measurement of differences in the natural abundance of 18O and 16O isotopes and their ratio was developed. The instrumental mass discrimination of the 18O/16O ratio was determined using three O-isotope samples of different chemical composition. The measured precision (the standard error of 100 cycles/analysis) obtained for the oxygen isotopic measurement on the samples was typically ±1.1‰.  相似文献   

18.
寿旦  朱作艺  张扬  董宇  沈立锋  朱岩 《分析化学》2012,40(6):960-963
建立了一种离子色谱(IC)分离,脉冲安培电化学法(PAD)直接检测人体引流组织液中妥布霉素的分析方法.采用高交换容量阴离子交换柱和低浓度KOH在线淋洗分离,不需要采用衍生化和离子对-柱后加碱等实现分离,并可在短时间内完成妥布霉素的测定.采用本方法测定的妥布霉素线性范围为0.05~10 mg/L,线性相关系数为0.9997,保留时间、峰面积和峰高的相对标准偏差分别为0.14%,0.38%和0.81%,检出限为7.11 μg/L.本方法成功应用于骨髓炎患者引流组织液中妥布霉素的测定,样品实际加标回收率为100.8%.  相似文献   

19.
A CAMECA IMS 6F secondary ion mass spectrometer (SIMS) for the analysis of irradiated nuclear fuel has been installed in the Microbeam Analysis Laboratory of the Institute for Transuranium Elements (ITU). This device is specially equipped with heavy metal shielding to enable the safe examination of irradiated nuclear fuel samples with activities up to 75 GBq. At ITU the shielded SIMS will be used in conjunction with EPMA taking advantage of the complementary nature of the two techniques and will make important contributions to ongoing research programmes such as the safety of nuclear fuels, the partitioning and transmutation programme and the characterisation of spent fuels. The paper describes the shielded SIMS installation and presents a selection of results from the commissioning tests.  相似文献   

20.
研究了直接电导检测-离子色谱法分离测定BF4-及常见无机阴离子(F-、Cl-、Br-、NO3-、SO24-)。实验采用Shim-pack IC-A3阴离子交换色谱柱,分别选用邻苯二甲酸氢钾、对羟基苯甲酸 三(羟甲基)氨基甲烷 硼酸、邻苯二甲酸 三(羟甲基)氨基甲烷为淋洗液,考察了淋洗液种类、浓度、色谱柱温度、流速对分离测定BF4-及常见无机阴离子的影响。确定最佳色谱条件为:以1.25 mmol/L邻苯二甲酸氢钾为淋洗液,流速1.5 mL/min,柱温45℃。在此条件下可同时基线分离6种阴离子,且色谱峰形对称。所测阴离子的检出限为0.02~0.58 mg/L;峰面积的相对标准偏差(RSD,n=5)小于0.8%。将方法应用于测定离子液体中的BF4-及其它无机阴离子,加标回收率在98.2%~102.7%之间。  相似文献   

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