Simultaneous determination of trace level bromate and chlorinated haloacetic acids in bottled drinking water by ion chromatography

A convenient and sensitive method for the simultaneous determination of trace level of bromate and chlorinated haloacetic acids in bottled drinking water with ion chromatography is presented. With a high capacity anion-exchange column and 11.5 mmol/l Na₂CO₃ eluent, all the 16 analytes could be separated in one injection within 31 min. By employing a microwave based evaporation technique, the bottled drinking water sample could be concentrated tenfold in 10 min. The recoveries of the compounds ranged from 90.6 to 107.2%. With a 500 μl large volume injection and high performance anion Atlas electrolytic suppressor, the detection limits were 0.06, 0.08, 0.06, 0.14 and 0.85 μg/l for BrO₃⁻, ClO₃⁻, monoacetic acid, dichloroacetic acid and trichloroacetic acid, respectively.     

Determination of bromate in sea water using multi-dimensional matrix-elimination ion chromatography

A multi-dimensional matrix-elimination ion chromatography approach has been applied to the determination of bromate in seawater samples. Two-dimensional and three-dimensional configurations were evaluated for their efficacy to eliminate the interference caused by the high concentration of ubiquitous ions present in seawater, such as chloride and sulfate. A two-dimensional approach utilising a high capacity second dimension separation comprising two Dionex AS24 columns connected in series was applied successfully and permitted the determination of bromate in undiluted seawater samples injected directly onto the ion chromatography system. Using this approach the limit of detection (LOD) for bromate based on a signal to noise ratio of 3 was 1050 μg/L using a 500 μL injection loop. Good linearity was obtained for bromate with correlation coefficients for the calibration curves of 0.9981 and 0.9996 based on peak height and area, respectively. A three-dimensional method utilising two 10-port switching valves to allow sharing of the second suppressor and detector between the second and third dimension separations showed better resolution and detection for bromate and reduced the LOD to 60 μg/L for spiked seawater samples. Good linearity was maintained with correlation coefficients of 0.9991 for both peak height and area. Ozonated seawater samples were also analysed and exhibited a non-linear increase in bromate level on increasing ozonation time. A bromate concentration in excess of 1770 μg/L was observed following ozonation of the seawater sample for 120 min. Recoveries for the three-dimensional system were 92% and 89% based on peak height and area, respectively, taken over 5 ozonated samples with 3 replicates per sample.     

Chloride interference in the determination of bromate in drinking water by reagent free ion chromatography with mass spectrometry detection

Bromate, a well known by-product of the ozonation of drinking water, has been included among the substances which have to be monitored in the drinking water according to the last EC Directive 251/98 on potable water with a regulated limit of 10 microg l(-1). The need of performing routine analysis at this limit is a driving force for the developing of new simple and sensitive methods of detection, which should be also able to overcome the effect of matrix composition. This work explored the use of mass spectrometry detection with electrospray ionisation hyphenated to a reagent free ion chromatograph with hydroxide gradient elution for the determination of bromate in drinking water. The use of a high capacity hydroxide selective column operated in gradient mode allowed to avoid the interference by carbonate peak, which moved to longer retention times. The effect of increasing chloride concentrations from 0 to 250 mg l(-1), which is the guideline limit for drinking water in Directive 251/98/EC, was to decrease absolute mass spectrometric response and chromatographic efficiency and, on the consequence, to increase the effective detection limits. The effect of the chloride concentration on the detection of bromate is discussed.     

Determination of bromate in drinking water by ultraperformance liquid chromatography-tandem mass spectrometry

Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water.     

Determination of trace inorganic anions in seawater samples by ion chromatography using silica columns modified with cetyltrimethylammonium ion

Conventional silica columns dynamically modified with cetyltrimethylammonium ions were evaluated for the determination of UV-absorbing bromide, nitrate, and nitrite in seawater samples. Cetyltrimethylammonium, which is a quaternary ammonium ion, was dynamically introduced onto silica surfaces. The first layer of the modifier was introduced by electrostatic interaction, whereas the second layer was introduced by hydrophobic interaction. The latter layer worked as the anion-exchange sites. The modified conventional silica columns could be used for separation of inorganic anions. Separation of authentic mixture of five anions was achieved within 17 min. The addition of 0.1 mM cetyltrimethylammonium ion to the eluent improved the repeatability of the retention time. Seawater samples could be directly injected onto the prepared conventional silica columns, and bromide, nitrate, and nitrite levels were determined to be 69, 0.13, and 0.016 ppm, respectively.     

Analysis of 500-ng/l levels of bromate in drinking water by direct-injection suppressed ion chromatography coupled with a single, pneumatically delivered post-column reagent

In July 1997, the US Environmental Protection Agency (EPA) began sampling and analyzing drinking water matrices from US municipalities serving populations greater than 100 000 for low-level bromate (>0.20 μg/l) in support of the Information Collection Rule (ICR) using the selective anion concentration (SAC) method. In September 1997, EPA published Method 300.1 which lowered the Method 300.0 bromate method detection limit (MDL) from 20.0 to 1.4 μg/l. This paper describes the research conducted at the EPA’s Technical Support Center laboratory investigating a single post-column reagent, o-dianisidine (ODA), which has been successfully coupled to EPA Method 300.1 to extend the MDL for bromate. Initial studies indicate that this method offers a MDL which approaches the EPA’s SAC method with the added benefit of increased specificity, shortened analysis time and reduced sample preparation. The method provides excellent ruggedness and acceptable precision and accuracy with a bromate MDL in reagent water of 0.1 μg/l, and a method reporting limit of 0.50 μg/l.     

微波炉浓缩甲基橙光度法测定饮用水中溴酸盐的研究

建立了一种微波浓缩甲基橙分光光度法测定水中溴酸根离子的方法。考察了酸度、时间、温度和甲基橙用量对测定方法的影响。分别对从各大超市购买的不同瓶装饮用水,经过微波炉浓缩后,用甲基橙分光光度法进行测定。其结果与离子色谱标准方法对比,结果表明:两种方法测定同一水样的相对误差小于7.0%。溴酸根离子氧化甲基橙使其褪色的最大吸收波长为510nm;溴酸根离子的浓度在0.0～1.0 mg/L范围内符合比尔定律。回归方程为:Y=0.9299X-0.0001,相关系数为r=0.9992。     

吸附柱分离-离子色谱法测定锑中微量硫

建立了吸附柱分离-离子色谱法测定锑样中微量硫的方法.方法采用王水,氢溴酸,浓HCl等试剂将锑样溶解,并使锑样中的硫转化为SO42-,低温加热蒸干,使锑完全挥发.然后在氧化铝柱上过柱,用氨水洗脱,最后将处理好的样品溶液注入离子色谱系统进行分析测定.优化了离子色谱操作条件,以流速为1.2 mL/min的3.5 mmol/L的Na2CO3与1.0 mmol/L的NaHCO3作为淋洗液,对标准液和样品溶液的测定,线性范围为0.2～100 μg/mL,检出限为0.2 μg/mL,回收率为92.9%～103.1%,该法适合锑样中微量硫的测定.     

盐析微萃取-气相色谱法测定饮用水中痕量甲苯

采用正丁醇为萃取剂,硫酸铵为盐析剂,建立了盐析微萃取-气相色谱法测定饮用水中痕量甲苯的分析方法,并对影响相分离的各种条件进行了优化。当水相体积为10m L,萃取剂正丁醇为300μL,盐析剂硫酸铵为4.5g,萃取时间为10min时,甲苯在0.01~0.50mg·L-1和0.50~25.00mg·L-1浓度范围内与峰面积呈线性关系,相关系数分别为0.99987和0.99982,方法的检出限为0.002mg·L-1,对于质量浓度为0.50mg·L-1的甲苯进行7次反复测量,得到其相对标准偏差为4.3%。该方法用于饮用自来水和河水中痕量甲苯的测定,平均回收率分别为91.59%和92.17%。     

Use of ion chromatography with post-column reaction for the measurement of tribromide to evaluate bromate levels in drinking water

A user-friendly ion chromatography method in conjunction with a post-column reaction (PCR) achieves practical quantitation limits for the oxyhalides bromate and chlorite of 0.05 μg/l and 0.10 μg/l, respectively. This level of measurement allows for the accurate assessment of bromate contributed to finished drinking waters that have been chlorinated using sodium hypochlorite. The target sensitivity of oxyhalides in the presence of other major ion species typically found in drinking water is achieved by PCR using excess bromide under acidic conditions to form a tribromide species that is detected by ultraviolet spectrometry. The method setup involves non-hazardous materials, as opposed to other recently developed methods that employ somewhat hazardous chemicals for generating the reaction necessary for the detection of bromate at sub-μg/l levels. No pretreatment of the samples is required, other than filtration and quenching of oxidant residual.     

高压离子色谱法快速测定饮用水中7种无机阴离子

建立了使用高压离子色谱快速测定饮用水中7种无机阴离子的方法。环境水样经0.22 μm尼龙滤膜过滤后可直接进样分析。采用Dionex Integrion高压离子色谱仪和AS22-Fast-4 μm阴离子交换柱（150 mm×4 mm）,可在5 min内完成对F^-、Cl^-、Br^-、NO₂^-、NO₃^-、SO₄^2-和PO₄^3-这7种阴离子的分析。以4.5 mmol/L碳酸钠和1.4 mmol/L碳酸氢钠为淋洗液,流速为2mL/min。7种阴离子的检出限为0.007~0.07 mg/L（S/N=3）,在较宽范围内有良好的线性关系（相关系数不小于0.999）和重现性（相对标准偏差不大于0.48%,n=8）。实际样品加标回收率为91.4%~109.7%,相对标准偏差为0.30%~0.45%（n=5）。将该方法应用于饮用水厂进出水的分析,结果表明在进出水中检出6种阴离子,以Cl^-、NO₃^-和SO₄^2-为主。该方法简便快速、灵敏准确,尤其适合高通量样品中阴离子的快速分析。     

膜萃取-气相色谱/质谱法测定瓶装饮用水中27种有毒有害物质含量

利用C18固相萃取膜与气质联用(GC-MS)技术建立了瓶装饮用水中27种痕量化合物多残留同时检测的方法.水中被测物多残留通过C18固相萃取膜富集,丙酮洗脱,旋转蒸发与吹氮浓缩,GC/MS选择离子监测模式(SIM)测定.被测物加标回收率在60%～120%之间,相对标准偏差小于25%.     

Determination of trace level perchlorate in drinking water and ground water by ion chromatography

Ammonium perchlorate, a key ingredient in solid rocket propellants, has recently been found in ground and surface waters in the USA in a number of states, including California, Nevada, Utah, and West Virginia. Perchlorate poses a health risk and preliminary data from the US Environmental Protection Agency reports that exposure to less than 4–18 μg/l provides adequate human health protection. An ion chromatographic method was developed for the determination of low μg/l levels of perchlorate in drinking and ground waters based on a Dionex IonPac AS11 column, a 100 mM hydroxide eluent, large loop (1000 μl) injection, and suppressed conductivity detection. The method is free of interferences from common anions, linear in the range of 2.5–100 μg/l, and quantitative recoveries were obtained for low μg/l levels of perchlorate in spiked drinking and ground water samples. The method detection limit of 0.3 μg/l permits quantification of perchlorate below the levels which ensure adequate health protection. A new polarizable anion analysis column, the IonPac AS16, and its potential applicability for this analysis is also discussed.     

大体积进样-浓缩柱在线富集-离子色谱法测定水中痕量及超痕量溴酸盐

建立了一种测定水中痕量及超痕量溴酸盐的在线富集大体积进样离子色谱法。采用实验室常备的柱容量较高的Dionex IonPac AG23保护柱作为浓缩柱,连接在定量环处富集溴酸盐。淋洗液自动发生装置在线生成高纯度氢氧化钾淋洗液进行梯度洗脱,抑制电导检测。实验结果表明:溴酸盐质量浓度范围在0.05~51.2 μg/L之间时线性关系良好,相关系数r≥0.9995,方法检出限为0.01 μg/L。与常规进样相比,进样量可高达5 mL,浓缩因子约为240倍。本方法成功应用于市售纯净水中溴酸盐的测定,2个加标水平的回收率在90%~100%之间,RSD(n=6)为2.1%~6.4%。该方法无需前处理,操作简单,准确度和精密度良好。通过大体积进样实现高倍富集,适用于痕量及超痕量溴酸盐的分析。     

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

A new and simple method was developed to determine anions in oxalate of analytical reagent grade.After UV photolysis with optimal 1%H₂O₂ in 10,000 mg/L oxalate in the fabricated photoreactor,sample was directly injected into IC system.Satisfactory linearity,detections limits,good repeatability and spiked recovery were obtained.The method was successfully applied to determine anions in two commercial oxalate samples.     

单泵柱切换离子色谱法分析复杂基体中痕量阴离子

本文通过离子色谱与柱切换技术联用实现了高浓度样品基体中的痕量阴离子检测.分别研究了不同类型基体的处理方法,使用商品化离子排斥柱和自制的聚合物色谱柱实现多种样品基体中痕量阴离子的检测.同时开发一种简化的单泵柱切换系统,利用抑制器将KOH淋洗液转化为水作为前处理柱的淋洗液,在同一个色谱系统中产生两种淋洗液,实现色谱分离与前...     

离子色谱法检测酸性镀铜液中的微量氯离子

采用Na2CO3-NaHCO3为淋洗液和抑制电导检测,对酸性镀铜液中的微量氯离子进行检测。采用AgNO3作为沉淀剂使Cl-分离富集,再用Na2S2O3溶液溶解沉淀后进行检测,可以很好地消除酸性电镀液中高浓度SO4^2-的干扰。该方法线性良好,Cl^-的检出限为0.01μg/mL,回收率在98.6%-101.7%之间,由于该方法能够很好地消除大量SO4^2-的干扰,在电镀铜工业中对酸性镀铜液中氯离子的监控可发挥作用。     

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%.     

Determination of trace level bromate and perchlorate in drinking water by ion chromatography with an evaporative preconcentration technique

A simple sample preconcentration technique employing microwave-based evaporation for the determination of trace level bromate and perchlorate in drinking water with ion chromatography is presented. With a hydrophilic anion-exchange column and a sodium hydroxide eluent in linear gradient, bromate and perchlorate can be determined in one injection within 35 min. Prior to ion chromatographic analysis, the drinking water sample was treated with an OnGuard-Ag cartridge to remove the superfluous chloride and concentrated 20-fold using a PTFE beaker in a domestic microwave oven for 15 min.The recoveries of the anions ranged from 94.6% for NO2- to 105.2% for F-. The detection limits for bromate, perchlorate, iodate and chlorate were 0.1, 0.2, 0.1 and 0.2 microg/l, respectively. The developed method is applicable for the quantitation of bromate and perchlorate in drinking water samples.     

Determination of iodide in seawater using C30 column modified with polyoxyethylene oleyl ether in ion chromatography

An ion chromatographic method for rapid and direct determination of iodide in seawater samples is reported. Separation was achieved using a laboratory-made C30 packed column (100 mm × 0.32 mm i.d.) modified with polyoxyethylene oleyl ether, with an aqueous solution of 300 mM sodium chloride as eluent and using UV detection at 220 nm. Samples containing iodate, nitrate, iodide and thiocyanate were eluted within 8 min, and the relative standard deviations of the retention time, peak area and peak height were all smaller than 4.19% for all of the analyte anions. Effects of eluent composition on retention behavior of inorganic anions have been investigated. Both cation and anion of the eluent affected the retention time of analytes. When inorganic eluents, such as ammonium chloride, ammonium sulfate, lithium chloride, sodium chloride, sodium sulfate, magnesium chloride and magnesium sulfate were used, the retention time of analytes increased with increasing eluent concentration. The limit of detection of iodide was 19 μg l⁻¹ (S/N = 3), while the limit of quantitation was 66 μg l⁻¹ (S/N = 10). The present method was successfully applied to the rapid and direct determination of iodide in seawater samples.