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.     

Analysis of bromate in drinking water using liquid chromatography-tandem mass spectrometry without sample pretreatment

An analytical method for determining bromate in drinking water was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The (18)O-enriched bromate was used as an internal standard. The limit of quantification (LOQ) of bromate was 0.2 μg/L. The peak of bromate was separated from those of coexisting ions (i.e., chloride, nitrate and sulfate). The relative and absolute recoveries of bromate in two drinking water samples and in a synthesized ion solution (100 mg/L chloride, 10 mg N/L nitrate, and 100 mg/L sulfate) were 99-105 and 94-105%, respectively. Bromate concentrations in 11 drinking water samples determined by LC-MS/MS were <0.2-2.3 μg/L. The results of the present study indicated that the proposed method was suitable for determining bromate concentrations in drinking water without sample pretreatment.     

Sensitive reaction rate method for the determination of low levels of formaldehyde with photometric detection

A simple and rapid method is proposed for the determination of ultra trace amounts of formaldehyde. It is based on the catalytic effect of formaldehyde on the oxidation of Brilliant cresyl blue by bromate. The reaction is monitored photometrically by measuring the decrease in absorbance of the dye. Formaldehyde in the range of 0.005–2.300 μg/mL can be determined with a limit of detection of 0.003 μg/mL. The relative standard deviation for ten replicate measurements of 1.5 μg/mL formaldehyde is 0.1%. The method was used for the determination of formaldehyde in real samples with satisfactory results.     

紫外分光光度法检测水中微量溴酸盐的含量

基于BrO3-与I-在酸性介质中发生氧化还原反应形成具有紫外吸收的I3-的性质,采用了紫外分光光度法测定水体中微量溴酸盐含量,方法加标回收率在98%～102%之间,相对标准偏差RSD为1.7%,线性相关系数为0.9991,检测限为4.0μg/L,能满足现有标准的检测要求。     

催化动力学极谱法测定痕量钒

在硫酸介质中,以酒石酸为活化剂,痕量钒对溴酸钾氧化甲基橙的反应有极强的催化作用,以极谱法监测催化反应过程中甲基橙及其氧化产物浓度的变化,建立了双峰指示催化动力学极谱法制定痕量钒的新方法,方法的线性范围为0.23-3.70μg/L,检出限为0.17μg/L。方法已用于食品及水样中痕量钒的测定。     

Spectro photometric determination of bromate with o-arsanilic acid

o-Arsanilic acid reacts with bromate ions in dilute acid solution and forms a reddish-brown color which is suitable for the spectrophotometric determination of bromate. The reaction has a sensitivity of 0.05 μg BrO₃^- per cm2 for log $\text{I}{}_{\mathrm{o}}\text{l}$ = 0.001 and obeys Beer's law up to 50 p.p.m.The standard deviation for the color development (387 p.p.m. brornate) is 0.95%, and 0.52% in the determination of bromate in salt solutions.Optimum analytical conditions for the reaction have been established and a procedure for the spectrophotometric determination of bromate is given.     

离子色谱法测定瓶(桶)装纯净水中痕量溴酸盐和亚硝酸盐的含量

采用离子色谱法同时测定瓶(桶)装纯净水中溴酸盐和亚硝酸盐的含量。水样经AG19-4mm保护柱及DIONEX AS19色谱柱分离,以不同浓度的氢氧化钾溶液为淋洗液,溴酸盐和亚硝酸盐得到很好的分离。BrO3-和NO2-分别在5.00～100.00μg.L-1和1.00～50.00μg.L-1范围内呈线性,检出限(3s/k)分别为0.08,0.14μg.L-1。方法用于瓶(桶)装水中溴酸盐和亚硝酸盐的测定,加标回收率在92.7%～98.4%之间,相对标准偏差(n=5)均小于5.0%。     

离子色谱法测定饮用水中痕量溴酸盐

建立了一种利用离子色谱法测定饮用水中痕量溴酸盐(BrO<,3><'->)的方法.色谱条件为:IonPac AS19(250mm x4 mm)色谱柱分离,KOH 梯度淋洗,流速1.0 mL/min,抑制电导检测,外标法定量.BrO<,3><'->浓度在2.0～100μg/L范围内有良好的线性,检出限为0.3 ng/mL,...     

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。     

Trace analysis of bromate in drinking waters by means of on-line coupling IC-ICP-MS

The on-line-coupling of ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool for the determination of bromate in drinking waters. The use of a high-capacity and high-performance anion-exchanger combined with an NH₄NO₃-based elution system allows the determination of bromate in almost every water sample without any sample pretreatment. The method detection limits in the water samples investigated are 50 to 65 ng/L or 44 to 58 pg bromate, respectively. Considering sensivity as well as imprecision (5% at 500 ng/L bromate) and short analysis times (8 to 15 min per sample including sample uptake), the described IC-ICP-MS coupling is well suited for precise routine analyses of bromate in drinking waters at the sub μg/L level.     

Amperometric titrations with rotated platinum electrode: Determination of hydrazine by potassium bromate

The reaction between hydrazine and potassium bromate is studied amperometrically at rotating platinum electrode. The bromate titration is performed at an applied e.m.f. of zero (versus S.C.E.) and in the presence of bromide and 1–5N sulfuric acid or 0.5–4N hydrochloric acid. Quantities ranging from 30 μg to 3 mg of hydrazine can be estimated accurately by this method. Determination of phenylhydrazine, Semicarbazide and other oxidizable materials on similar lines is suggested.     

抑制型电导检测离子色谱法测定饮用水中的痕量溴酸盐

建立一种直接进样测定饮用水中痕量溴酸盐的电导检测离子色谱法。选用Metrosep A Supp 5阴离子交换分离柱,碳酸盐淋洗液。抑制型电导检测采用化学抑制器和CO2抑制器顺序双抑制系统。实验结果显示,溴酸根阴离子与常见共存阴离子完全分离,溴酸盐含量在5~100 μg/L范围内具有良好的线性(r=0.9999),精密度高(相对标准偏差（RSD）<4%),方法的检出限为0.50 μg/L,样品加标平均回收率为96.1%~107%。该方法操作简单,分离效果好,可与常见阴离子实现同时分析,灵敏度高,重现性好,可作为饮用水中溴酸盐的标准测定方法。     

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。     

二甲酚橙-溴酸钾体系催化动力学光度法测定微量甲醛

在硫酸介质中,溴酸钾在甲醛的催化作用下能氧化二甲酚橙褪色,其褪色程度与甲醛含量成正比,从而建立了光度法测定微量甲醛的新方法。方法的最大吸收波长为435 nm,在50℃水浴中反应10 min,甲醛含量在0～20μg/mL内呈线性关系。方法应用于废水中微量甲醛的测定,相对标准偏差为4.34%,回收率在91.0%～102.8%之间。     

溴酸钾氧化孔雀石绿和甲基橙褪色光度法测定水中亚硝酸根

在H3PO4介质中,利用痕量NO2-催化KBrO3氧化孔雀石绿和甲基橙褪色的反应,建立了双波长双指示剂催化动力学光度法测定痕量NO2-的新方法。该反应在最大吸收峰505nm和615nm处,催化和非催化体系吸光度的变化与NO2-浓度呈线性关系,线性范围为0.01～0.80μg/mL,检出限为1.3×10-3μg/mL,该方法用于环境水样(自来水、雨水、延安卷烟厂废水)中痕量NO2-的测定,加标回收率为97%～110.2%.     

Flow-injection chemiluminometric analysis of some steroids by their sensitizing effect on the bromate-sulphite reaction

The chemiluminescent oxidation of sulphite by bromate was investigated and compared with that by cerium(IV). The reaction is sensitized by various steroid hormones which can thus be determined in the ranges 0.50–20.0μg ml ¹ for cortisone; 0.50–5.00 μg ml^?1 for hydrocortisone and progesterone and 0.50–6.00 μg ml^?1 for testosterone and corticosterone.     

Differential pulse polarographic determination of traces of iron in solar-grade silicon

Iron is determined, after volatilization of the matrix as hexafluorosilicic acid, by means of the polarographic iron(III) wave in a 0.1 M triethanolamine—0.1 M potassium bromate—0.5 M sodium hydroxide medium. Differential pulse polarography provides a detection limit of about 0.15 μg g^-1 with a precision of 1–2% and linear calibration graphs up to 0.5 μg Fe(III) ml^-1.     

Kinetic Flow Injection Spectrophotometric Determination of Nitrite by its Catalytic Effect on the Oxidation of Chlorophosphonazo-pN by Bromate

Abstract

A flow injection kinetic method has been developed for the determination of nitrite, based on its catalytic effect on bromate oxidation of chlorophosphonazo-pN in H₂SO₄ medium. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 551 nm. The sampling frequency was 83 h^?1. The calibration curve was linear between 0.050 and 1.00 μg/ml, and the detection limit was 0.018 μg/ml. The proposed method was applied to the determination of nitrite in waters and soil with satisfactory results.     

柱前衍生化高效液相色谱法(HPLC)测定水中微量溴酸盐含量

联合柱前衍生化技术,成功地用高效液相色谱法(HPLC)测定了水体中微量溴酸盐含量。通过衍生化条件的优化,方法回收率在98%～105%之间、相对标准偏差RSD小于2.0%,线性相关系数达0.9995,检测限为1.0μg/L。方法简便快速、准确可靠,能满足现有标准的检测要求。     

Colorimetric determination of persulfate with alcian blue

Alcian blue buffered at pH 2.5 is oxidized by persulfate. The plot of optical density at 615 mμ vs. concentration of persulfate (within the range of 10 to 80 μg) is linear. The assay is not affected by bromate and iodate.