采用离子色谱法测定饮用水及环境水样中的溴酸盐

采用离子色谱方法测定了饮用水及环境水样中溴酸盐的含量,水样经Ion Pac AS11-HC阴离子分析柱和IonPac AG11-HC(4×250 mm)保护柱分离,以不同浓度的Na OH溶液为淋洗液;Br O3-在0.0157-1.57μg/L的范围内线性关系良好,检出限为0.005mg/L,空白水样的加标回收率在87.1%~110.2%之间,相对标准偏差(n=6)均小于5.0%。     

离子色谱法在电厂水质分析中的应用研究

我国在水质分析方面大多采用了离子色谱法,离子色谱法由于本身具有的优越性以及独特性,因此在我国的水质分析领域受到广泛的欢迎。本文从离子色谱法的概述中讲述它在试验中的作用。     

高效液相色谱法测定复原乳中糠氨酸的含量

建立了测定复原乳中糠氨酸含量的高效液相色谱分析方法.复原乳中的糠氨酸用6.0mol/L盐酸水解后,经Discovery C(u)色谱柱分离,采用紫外检测器检测.本方法复原乳中的糠氨酸在(1.0～20.0)mg/L质量浓度范围内呈良好的线性关系,相关系数r≥0.9992.方法的重复性好,RSD不大于1.09%.加标回收率为92.0%～96.2%,方法的检测限(s/N=3)为0.5mg/kg.本文所建立的方法简便、快速,适用于复原乳中糠氨酸含量的测定.     

氦离子色谱仪在超高纯氨分析中的应用

随着产业的发展,对超高纯氨的需求越来越大,品质要求也越来越高。因此对于氨气中的杂质控制也更加严格。详细介绍了GC-9560-HG氦离子化气相色谱仪在超高纯氨分析中的应用。该色谱仪可准确测定超高纯氨气中的杂质。     

固相微萃取——气相色谱法测定污水中的苯系物

采用固相微萃取(SPME)和气相色谱(GC)技术对污水中苯系物进行了分析测定.针对要检测的几种苯系物,采用100μm聚二甲基硅氧烷(PDMS)作为固相微萃取(SPME)装置的固相涂层,并对SPME的参数进行了优化.本方法的重复性好,相对偏差＜5%;线性范围较宽,在0.10～10.0μg/L浓度范围;色谱峰面积与溶液浓度具有良好的线性关系,相关系数＞0.997;检测限均低于0.07μg/L;回收率为88.3%～114.0%.     

高效液相色谱法测定食醋中苯甲酸和山梨酸

研究了一种用蒸馏法提取、高效液相色谱法测定食醋中苯甲酸和山梨酸的方法.用蒸馏法提取食醋中的苯甲酸和山梨酸.收集蒸馏液直接进行液相色谱分析.苯甲酸和山梨酸标准溶液在0.25 mg/L～100mg/L内线性良好,其线性相关系数分别为0.9999和0.9998,加标回收率为95.0%～105.2%,测量结果的相对标准偏差为2.46%～3.45%.该方法用于测定食醋样品中的苯甲酸、山梨酸,检测下限均为0.5mg/L.     

燃烧氧化偶联离子色谱法检测甲醇中有机氯

本文提出采用燃烧氧化偶联离子色谱法测定甲醇中有机氯含量的新方法。方法先用离子色谱法直接定量甲醇中无机氯含量,再用离子色谱法测量甲醇中所含的总氯在燃烧氧化过程生成的Cl_2、HCl、气态的无机氯化合物被I吸收生成的Cl~-来定量甲醇中总氯含量。由测得的总氯含量和无机氯含量,计算得甲醇中有机氯含量。实验结果表明该方法经济、简单、准确、灵敏。     

离子色谱法测定饮用水中常见阴离子

本文主要介绍离子色谱法检测饮用水中常见阴离子的方法。本方法采用瑞士万通的761型离子色谱仪。分离柱为METROSEPAnionDual2,淋洗液为2.0mmol/LNaHCO3和1.3mmol/LNa2CO3抑制液为20mmol/LH2SO4在测定范围内,F-、Cl-、NO2-、NO32-;-SO42-的峰面积和质量浓度呈线性关系,相关系数均大于0.999。回收率F-为101.5%,CL-O101.6%,NO2-为108.0%.NO32-为97.7%,SO42-为103.3%。相对标准偏差在0.7%-4.3%之间。     

离子色谱法测定水和废水中乙酸

本文利用离子色谱法,经自动进样器直接进样,测定水和废水中的乙酸,方法检出限为0.130 mg/L,方法RSD为0.203%至0.267%,且具有较高的回收率。     

离子色谱法测定地表水中的溴酸盐

建立了单柱阴离子色谱测定地表水中溴酸根的方法,并对实际水样进行了测定。溴酸盐浓度在0．01—4．0mg／L范围内与峰面积线性回归相关系数O．9993,检出限为O．02mg／L,保留时间和峰面积相对标准偏差分别为0．13％和0．92％,回收率为96．2—103．5％。     

Extended thermodynamic approach to ion interaction chromatography

The chromatographic behavior of charged analytes in ion interaction chromatography (IIC) is theoretically investigated. The chemical modifications of the stationary and mobile phases in the presence of ion interaction reagent (IIR) are theoretically shown to change the partition coefficient for charged molecules. The most reliable literature experimental results concerning retention behavior of charged molecules in IIC were used to test the new theory. Retention equations are compared with those that can be obtained from the most important retention models in IIC. The present exhaustive retention model, which is well-founded in physical chemistry, goes further than the previous ones whose retention equations can be viewed as limiting cases of the present theory. The present extended thermodynamic approach reduces to stoichiometric or electrostatic retention models if the surface potential or pairing equilibria are respectively neglected. Moreover, it is able to quantitatively explain experimental evidences that cannot be rationalized by the existing retention models.     

Use of ion mobility spectrometry to determine low levels of impurities in gases

The use of ion mobility spectrometry (IMS) for the determination of trace moisture and oxygen in bulk nitrogen has been explored. IMS utilizes atmospheric pressure ionization to ionize trace impurities in the sample gas. Mobility differences between trace impurity ions are exploited to separate these ions. Our results indicate that an IMS can indeed be used to detect < 1 ppb O2 and H2O in bulk nitrogen. Due to the nature of the interaction between trace moisture and oxygen, a multivariate calibration has to be used to obtain quantitative results, even at levels below 2 ppb.     

Determination of nitrite in drinking water and environmental samples by ion exclusion chromatography with electrochemical detection

An extremely sensitive determination of nitrite in drinking water (tap water and underground water) and environmental samples (rain, lake water, and soil) was achieved by ion exclusion chromatography (IEC) with electrochemical (EC) detection. Potential interferences in the determination of nitrite by the standard spectrophotometric method or by the ion exchange chromatographic method with either conductivity detection or UV detection were eliminated. The detection limit was 0.1 ppb without preconcentration. No nitrite was observed from tap water or underground drinking water. The recoveries of nitrite added to tap water at 0.02, 0.1, and 1 ppm levels were between 96 and 104.5%. The average coefficient of variation was 4.7%. The recovery results were in good agreement with those obtained by the standard spectrophotometric method. Nitrite concentrations between 0.068 and 0.19 ppm were observed in rain within a week period. A greater variation, between 0.015 and 0.26 ppm, was observed in lake water. Amounts of 19.1 ppm and 0.50 ppm nitrite were observed from fertilized and unfertilized soil, respectively.     

减量蒸馏法测定废水中挥发酚的探索

在4-氨基安替比林直接分光光度法测定挥发酚的基础上,采用50mL水样进行预蒸馏,然后按标准分析方法进行后续操作,实验测定标准样品的结果在保证范围内,加标回收率在90%-105%之间,平行测定相对标准偏差为1.8%,与标准方法无显著性差异。减量蒸馏法节省了时间,减少了与水电的消耗,提高了监测分析效率。     

Determination of trace perchlorate in high-salinity water samples by ion chromatography with on-line preconcentration and preelution

A simple, automated system for the determination of trace perchlorate by ion chromatography (IC) with an online preconcentration technique is reported. The sample is preconcentrated, and less strongly held ions preeluted before the analyte is transferred to the principal separation system. This approach provides low limits of detection (LOD) and is particularly robust toward the effect of high concentrations of common anions, such as those present in groundwater samples. It compares favorably with currently promulgated EPA method 314.0. The LOD (S/N = 3) is 0.77 microg/L for a 2-mL reagent water sample and decreases more-or-less proportionately with increasing sample volume, at least up to 20 mL. Even with a sample of conductivity 14.7 mS/cm (approximately that of 0.1 M Na2SO4), the recovery of added perchlorate at the 25.0 microg/L level was still 92%. The concentration of added perchlorate in the range of 1-400 microg/L was linearly correlated to the peak area, with an r2 value of 0.9997. The recovery of perchlorate from artificial samples with different conductivity by the present method compares favorably with those from the currently recommended EPA Method. The ability of this approach to remove matrix interferences suggests that it would be also promising for perchlorate analysis in other challenging samples.