Determination of Inorganic Anions and Melamine in Fertilizers by Ion Chromatography

A chromatographic analysis method for determining inorganic anions and melamine in fertilizers was established using ion chromatography(IC).The fertilizer samples were extracted by ultrasonic method with 7 g/L trichloroacetic acid solution and centrifuged.The supernatant is purified by a solid phase extraction column.Then,the anions in the solution were purified using SH-AP-1(250 mm×4.0 mm)as a separation column,and measured by a suppressed conductivity detector;the melamine in the solution was separated using SH-CC-4(200 mm×4.0 mm)as a separation column and detected by a UV detector.The results show that the mass concentration of anions had a linear relationship with its peak area within a certain range,the linear correlation coefficient r of the standard curve was greater than 0.999,the recovery rate of spiked samples was 93.4%-104.4%,and the relative standard deviation(RSD)of the measured value(n=6)was less than 4%.Thus,this method is widely suitable for detection of anions and cations in a variety of fertilizer samples.

Separation of Inorganic Anions Using Methacrylate-Based Monolithic Column Modified with Trimethylamine in Ion Chromatography Capillary System

Methacrylate-based monolithic column was prepared in fused-silica capillary (80 ′ 0.32 mm i.d.) by in situ polymerizetion reaction using glycidyl methacrylate as monomer;ethylene dimethacrylate as crosslinker;1-propanol, 1,4-butanediol, and water as porogenic solvents. The monolith matrix was modified with trimethylamine to create strong anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by using Scanning Electron Microscope (SEM). This column had good mechanical stability and permeability. The effects of various mobile phases for separation of inorganic anions were investigated. Iodate, bromate, nitrite, bromide, and nitrate were separated within 11 min using100 mMpotassium chloride as mobile phase and detected at 210 nm. This method showed good precision of retention time, acceptable linearity and good sensitivity. Under the optimum condition, the RSD of the retention time was in the range of 1.09%-1.75% (n = 6). The calibration curve showed linear relationships between the peak area and the concentration. The limits of detection (LOD) and the limits of quantitation (LOQ) were between 0.08-0.18 mM and 0.26-0.61 mM, respectively. This method was applied to the determination of inorganic anions in tap water and ground water samples.

Organic acids and inorganic anions in Bayer liquors by ion chromatography after solid-phase extraction

A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate, glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.

Determination of inorganic anions in ethyl acetate by in-line hollow fiber membrane extraction with ion chromatography

在这个工作，一个新奇空纤维膜抽出者被设置用 deionized 水从乙醇醋酸盐提取无机的阴离子。在稍微可溶的器官的溶剂的无机的阴离子能被结合的同轴的空纤维膜抽出者决定离子层析起初时间。象磁性的激动人心的速度，抽取流动率和抽取时间那样的抽取过程的不同方面被优化完成高抽取效率和好分离结果。令人满意的线性范围，察觉的限制和好重覆性被获得。过程被使用在二件商业乙醇醋酸盐样品分析无机的阴离子。

Effect of Methanol in the Wash-Solvent Bottle and the OnGuard Cartridges on the Determination of Different Anions Using Ion Chromatography

The effect of using methanol in the flush-solvent bottle of the auto-sampler of Ion Chromatograph on the determination of sulfate ions was studied using AS11-HC 2 mm analytical column. The use of 50% methanol in the flush solvent bottle results in overestimation of sulfate concentration by 18%. However, the use of 10% methanol instead of 50% did not show such error in the determination of sulfate using the same column. Furthermore, the effect of using OnGuard-RP and OnGuard-P cartridges for sample pretreatment on the determination of different anions was also studies using AS14-HC 2 mm analytical column. The results indicate that using OnGuard-RP cartridge caused the concentration of fluoride, bromide, nitrate, phosphate and sulfate ions to be underestimated, whereas the concentration of chloride ions to be overestimated. The error in the determination of fluoride, bromide, nitrate, phosphate sulfate, and chloride was found to be 40.0%, 26.0%, 22.8%, 26.8%, 18.0%, and 25.0% of the certified standard concentration, respectively. It was also found that the use of OnGuard-P cartridge resulted in underestimation of fluoride, chloride, bromide, nitrate, phosphate, and sulfate by 60.0%, 40.0%, 82.0%, 87.2%, 45.2%, and 39.0% of the certified standard concentration, respectively. These findings point out to careful corrections that should be considered in any application of ion chromatography utilizing such sample pretreatment.

Analysis of trace elements in air particulate matters by non-suppressed ion chromatography

The application of non-suppressed ion chromatography for monitoring of trace elements in air particulate matter was studied in the present investigation. The results indicate that the use of microwave acid digestion method is superior in comparison with the conventional thermal acid digestion method as it leads to higher recovery, better reproducibility, lower volatility loss, better protection against environmental contamination and much less digestion time (5 minutes vs. 24 hours). The use of eluent as extractant is shown to reduce the water dip problem in the chro-matogram. The addition of chelating agent in the eluent coupled with UV detection is shown to provide satisfactory chromatographic separation and good sensitivity for the analysis of transition metals present in the air particulate matter. Using the U.S. National Bureau of Standards Reference Material 1648 Urban Particulate Matter as standard for checking, the analytical procedure is shown to give good recovery and reproducibility for the detection of the following cations and anions in air particulate matter: Fe2 Cu, Mn, Pb, Zn, Mg, Na, HN4+, Cl-, NO3- and SO42-. Field test was also performed to check the applicability of the method and the results obtained were discussed in the present paper.

Science Letters:Simultaneous determination of fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate, sorbate, and saccharin in gargles by ion chromatography

Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chroma-tography (IC) method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate (anticariogenic agents), sorbate (a preservative), and saccharin (an artificial sweetener) in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations (RSDs) of the inter-day's retention time and peak area of all species were less than 0.938% and 8.731%, respectively, while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90%~102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles.

Trace analysis of anions in organic matrices by ion chromatography coupled with a novel reversed-phase column for on-line sample pretreatment

An ion chromatography（IC） system coupled with on-line column-switching technique was used to determine anions ofμg/g levels in organic chemicals of analytical reagent grade.A novel polystyrene-divinylbenzene-carbon nanotube（PS-DVB-CNT） stationary phase was utilized for matrix elimination.A calibration study was conducted by preparing and analyzing eight concentrations（between 10 and 5000μg/L） of eight standards in deionized water.The linearity was between 0.9978 and 1.And the detection limits ranged from 1.54μg/L to 10.02μg/L.A spiking study was performed on two representative organic chemicals.The recoveries were between 84.3%and 119.6%.

Trace Analysis of Anions in Perfluorodecalin by Green Liquid-Liquid Extraction Combined with Ion Chromatography

Perfluoronaphthenes,with inert chemical and biological properties and ability to dissolve large amounts of oxygen,have received the most attention in medical applications.However,the excessive anion contained may cause some side effects.Herein,liquid-liquid extraction technique with shaking and ultrasonic extraction was used for the trace analysis of five anions(F^(-),Cl^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))in perfluorodecalin using water as green extractant.The optimum pretreatment technology and ion chromatography detection conditions were established.Good linearity was observed in each concentration range,and the linear correlation coefficient(R^(2))was better than 0.997.The limits of detection(S/N=3)of five anions from perfluorodecalin were 3.2,5.5,14.2,23.2 and 29.5μg/L,respectively.The established method with high sensitivity and accuracy has been successfully appliedfor the determination of five anions in three perfluorodecalin products,which provides a basis for further development of green detection and quality standard formulation in perfluorodecalin and other fluorocarbon solvents.

Determination of common anions in oxalate by ion chromatography coupled with UV photolysis pretreatment

一个新、简单的方法被开发在分析试剂等级的盐决定阴离子。在紫外光分解作用与以后最佳在在制作 photoreactor 的 10,000 mg/L 盐的 1% H2O2，样品直接被注入 IC 系统。令人满意的线性，察觉限制，好重覆性和刺的恢复被获得。方法成功地被使用在二件商业盐样品决定阴离子。

双通道离子色谱法测定陶质文物表面结晶盐中有机酸根和无机阴阳离子

对双通道离子色谱同时测定陶质文物表面结晶盐中的CH_(3)COO^(-)、HCOO^(-)、F^(-)、Cl^(-)、SO_(4)^(2-)、NO_(3)^(-)等9种阴离子和Li^(+)、Na^(+)、K^(+)等6种阳离子的测定方法进行优选。通过优化色谱条件,确定采用Metrosep A Supp7色谱柱为阴离子分析柱,3 mmol/L碳酸钠为阴离子淋洗液,流速为0.7 mL/min;Metrosep C4型色谱柱为阳离子分析柱,0.8 mmol/L吡啶二羧酸-1.6 mmol/L硝酸为阳离子淋洗液,流速为0.7 mL/min。在此方法下,净化后的滤液一次进样,电导检测器检测,各离子峰形好,分离时间适中,分离效果很好。各离子的标准曲线相关系数R>0.999,具有良好的线性关系,检出限在0.005~0.05 mg/L之间,加标回收率在96%~106%之间,相对标准偏差为0.1%~4%(n=5)。结果表明,瓦当表面结晶盐中主要含有Ca^(2+)、Na^(+)、CH_(3)COO^(-)、Cl^(-)、SO_(4)^(2-)、NO_(3)^(-)。该方法简单快速、准确度高,可有效分离文物表面结晶盐中的常见有机酸根离子和无机阴阳离子。

冷凝收集-离子色谱法测定呼出气中的有机酸和阴离子

建立了一种非侵入式冷凝收集-离子色谱方法测定人体呼出气中乳酸、甲酸、乙酸、丙酮酸、Cl^(-)、NO_(2)^(-)、NO_(3)^(-)、SO_(4)^(2-)。搭建自制呼出气冷凝装置,该装置包括吹气口、与吹气口相连的单向阀和流量计、置于半导体冷凝装置中的冷阱以及一次性冷凝收集管。通过呼出气冷凝装置对人体呼出气进行收集,利用离子色谱对冷凝液(EBC)中有机酸和阴离子的含量进行检测。优化采集冷阱温度和采集流量,得到冷阱最佳冷凝温度为-15℃,呼气流量为15 L/min。采用1.5 mmol/L碳酸钠和3 mmol/L碳酸氢钠混合溶液作为流动相,泵流速为0.8 mL/min,分析柱为IC-SA3(250 mm×4.0 mm),柱温为45℃。8种有机酸和阴离子的线性范围均为0.1~10.0 mg/L,相关系数均≥0.9993。在进样量为100μL时,方法的检出限为0.0017~0.0150 mg/L(S/N=3),定量限为0.0057~0.0500 mg/L(S/N=10)。方法的日内和日间精密度均≤7.50%(n=5)。采用该方法对5位健康受试者呼出气中的有机酸和阴离子进行检测,得到8种有机酸和阴离子的含量为0.18~42.3 ng/L。在10 km的长跑运动过程中,除了一位受试者代谢异常,其余受试者呼出气中的有机酸和阴离子含量总体变化趋势为先增加后减小。本方法采样过程简单,精密度好,且没有副作用,受试者不会产生任何明显不适或风险,可为日后人体代谢物的研究提供实验思路和理论依据。

双抑制在线基体去除-离子色谱法测定电池级碳酸锂中痕量阴离子

建立了一种测定电池级碳酸锂中痕量阴离子的方法。用超纯水超声辅助溶解碳酸锂,采用在线基体去除法去除碳酸锂基体,基体去除过程中,样品首先流入到ADRS600(4 mm)抑制器(抑制电流150 mA,抑制器再生液外接水流速2 mL/min)中,在抑制器内通过离子交换膜作用,碳酸锂中的锂离子与氢离子置换,碳酸锂变成碳酸;然后经过CRD 200(4 mm),碳酸以二氧化碳的形式排出离子色谱系统,从而达到去除碳酸锂基体的目的;最后待分析阴离子被自动富集在IonPac UTAC-LP2浓缩柱(35 mm×3 mm)上,通过阀切换技术将阴离子自动转移到色谱分析系统中。在色谱分析系统中,以IonPac AG18(50 mm×2 mm)为保护柱,IonPac AS18(250 mm×2 mm)为分析柱,柱温箱为30℃,KOH溶液为淋洗液进行梯度洗脱,泵流速0.30 mL/min,抑制器为ADRS600(2 mm),抑制电流25 mA,进样体积为250μL,检测器为电导检测器。结果显示:F^(-)、Cl^(-)、NO_(2)^(-)、Br^(-)、NO_(3)^(-)及SO_(4)^(2-)离子在各自的线性范围内具有良好的线性关系(r≥0.999);各离子的检出限和定量限分别为0.05~0.88μg/L和0.15~2.92μg/L;碳酸锂样品连续6针进样各离子峰面积的相对标准偏差(RSD)均≤0.73%;同一碳酸锂样品处理完后分别放置0、2、4、8、12、18、24 h后进样,各离子峰面积的RSD均≤0.96%;在3个添加水平下,各离子加标回收率为93.3%~99.3%,RSD(n=6)为0.97%~3.45%;本方法具有方法定量限低(各离子定量限均为0.5 mg/kg)及多种离子同时分析的优势,适用于电池级碳酸锂中痕量阴离子的检测。

液相色谱-离子色谱联用体系同时测定环境基质中的6种硝基芳烃类化合物和3种阴离子

同时测定环境土壤和水基质中的硝基芳烃类化合物和阴离子对于选择合适的硝基芳烃类化合物降解方法和实现地表水水质监测具有重要意义。本文通过两个六通阀和一根富集柱将高效液相色谱和离子色谱连接,搭建了色谱联用体系。系统操作可分为4个阶段:(A)样品加载到定量环;(B)分离硝基芳烃类化合物和阴离子;(C)阴离子在AG20柱中富集;(D)高效液相色谱和离子色谱分别测定硝基芳烃类化合物和阴离子。通过将液相色谱柱直接连接电导率检测器,确定阴离子流出液相色谱柱的时间,优化六通阀的切换时间,保证方法的准确性。在最优条件下,阴离子的检出限为0.005~0.020 mg/L,硝基芳烃类化合物的检出限为0.043~0.150 mg/L。3组不同加标浓度样品的平均回收率为88.20%~105.38%,相对标准偏差为2.0%~11.5%。该方法被用于检测5份地表水样品和5份土壤样品,硝基芳烃类化合物均未检出,3种阴离子在地表水样品中的检出量为0.41~55.3 mg/L,在土壤样品中的检出量为0.56~30.2 mg/kg。经过方法学验证和实际样品检测,证明该色谱联用体系检测方法自动化程度高,操作简单,重复性好,准确度高,具有广泛的适用性和较高的灵敏度,适用于环境基质中硝基芳烃类有机物和亚硝酸根离子等阴离子含量的快速测定。

离子色谱法测定玉溪北城“涩水”中4种无机阴离子

为了研究玉溪市北城“涩水”中无机阴离子的含量是否符合《生活饮用水卫生标准》中的限值,采用离子色谱法测定了玉溪北城“涩水”中F^(-)、Cl^(-)、NO_(3)^(-)、SO_(4)^(2-)的含量。结果表明,玉溪北城“涩水”中1月、2月、3月和4月的F^(-)、Cl^(-)、NO_(3)^(-)、SO_(4)^(2-)四种无机阴离子含量低于《生活饮用水卫生标准》中的限值。该方法标准曲线相关系数在0.9990以上,样品加标回收率在93.73%~109.20%之间,检出的数据准确可靠。结果为进一步探究“涩水”的水源保护和商用价值开发提供了数据支撑。

离子色谱法同时测定饮用水中的六种无机阴离子

建立离子色谱法同时测定饮用水中六种常见的无机阴离子(氟化物、氯化物、溴化物、亚硝酸盐、硝酸盐、硫酸盐)。选用亲水性的IonPac AS17阴离子交换色谱柱作为分离柱,用AG17-C作为阴离子保护柱。KOH溶液作为淋洗液,优化进样量、淋洗液浓度、淋洗程序、流速、柱温等测试条件后,采用电导检测器测定饮用水中六种目标阴离子的含量。结果表明:当进样体积为25μL时,六种目标阴离子在一定浓度范围内与其对应的峰面积呈线性关系,相关系数均大于0.999,氟化物、氯化物、溴化物、亚硝酸盐、硝酸盐、硫酸盐的最小检测质量浓度分别为0.002,0.002,0.000 2,0.000 5,0.000 09,0.000 08 mg/L。对每份样品进行三个水平的加标回收试验,加标回收率范围在87%~107%,测定结果的相对标准偏差为0.70%~3.96%。该方法具有选择性好、准确度高和操作便捷等优点,可应用于同时测定饮用水中多种阴离子的含量。

离子色谱-串联质谱法(IC-MS)同时测定蔬菜中17种阴离子型危害物

本研究建立了离子色谱-串联质谱法同时测定蔬菜中17种常见的阴离子型危害物的分析方法。结果表明,该方法能满足蔬菜中17种阴离子型危害物的高通量、快速、高灵敏度检测,且抗干扰能力强,可为蔬菜中多种常见阴离子型危害物的检测提供参考。

离子色谱法测定墓葬壁画土壤中4种阴离子

对离子色谱法快速测定墓葬壁画土壤中4种阴离子(F^(-)、Cl^(-)、SO_(4)^(2-)、NO_(3)^(-))的测定方法进行了优化。采用L_(9)(3^(4))正交实验确定了样品预处理的最佳参数:准确称取1.000 g样品加入20 mL超纯水,在振荡温度20℃,振荡转速180 r/min条件下提取40 min。淋洗液为25 mmol/L的KOH溶液,分析柱为Ion Pac AS11-SH(250 mm×4.0 mm),净化后的滤液通过电导检测器测定。在此方法下,各离子的检出限为0.066~0.078 mg/L,相对标准偏差为0.77%~2.23%(n=7),回收率为95.9%~105.8%。

仪器分析化学实验拓展与应用——离子色谱法测定生活饮用水中的阴离子

饮用水作为人类生存的基本需求之一,其安全性问题一直是影响民众生命健康的重要一环,对水质的检测也是国家指导工作的重点。基于南开大学化学学院仪器分析课程,综合文献资料,形成实验方案,在教师辅助指导下,结合实际问题深化和拓展了实验学习的理论和应用价值——利用离子色谱分析方法对日常生活饮用水中的阴离子种类及其含量进行了检测,确定各种生活饮用水的质量和差异性,同时鉴定其是否符合国家标准要求。该实验结果为人们选取安全饮用水提供了理论依据和指导建议。另外,本实验在激发学生学习兴趣的同时进一步巩固和加深了学生对离子色谱分析技术的理解与应用。该实验充分体现了理论联系实际,将仪器分析课程中学到的知识应用于生活,让学生能够从感性上更加深刻地领会和理解化学与日常生活的紧密联系。

自搭建离子色谱仪及其在无机阴离子检测方面的应用

为了帮助学生深入理解化学分析仪器的构造和工作原理,训练学生的创新思维、实践能力和团队协作能力,增强学生在化学分析仪器相关的基础实验中的参与感,设计了可供学生自行搭建离子色谱仪的新创实验,并将其应用于无机阴离子的检测。实验包含具有完整功能的离子色谱仪整机以及关键部件“电化学离子抑制器”的组装搭建,仪器基本功能的调试和性能测试以及自来水、湖水和茶水等实际水样中阴离子的定性和定量检测。该项目采用商品化的标准组件和自行加工的部件来搭建仪器,实验复现性高,还可以有效训练指导教师专业综合素质,显著提升基础实验教学效果和水平。与商品化整机比较,价格低廉,对教学经费投入要求低,适合在高校中化学及相关专业的仪器分析基础实验教学中推广。