Manufacture of Boron-free Magnesia with High Purity from Residual Brine

A novel method for removing boron with ion exchange resin from residual brines tomanufacture boron-free magnesia is described. The concentration of boron in the target magnesiamanufactured thereby from Qinghai salt lakes is lower than 5 μg/g, and the typical D50 size ofproduct is 10.625 μm.     

Boron Separation by the Two—step Ion—Exchange for the Isotopic Measurement of Boron

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新型酰乙基葡甲胺树脂的合成及吸硼性能

采用一步法, 用氯乙酰化聚苯乙烯树脂(PS-Acyl-Cl)与葡甲胺反应制得一种同时含有α-酰乙基胺和邻羟基双官能团的新型酰乙基葡甲胺树脂, 考察了溶液pH值、 温度、 初始浓度和吸附时间对酰乙基葡甲胺树脂吸附硼的影响. 结果表明, 在实验浓度范围内, 该树脂对硼的吸附符合Langmuir方程, 最大吸附量约为28.1 mg/g干树脂, 优于氯甲基树脂制得的硼特效树脂. 表明α-酰乙基胺和邻羟基双官能团对硼有双重或协同吸附作用. 该树脂在pH=6.0时对硼的吸附量最大; 温度对树脂吸附的影响不大; 树脂解吸率大于96%; 树脂重复使用5次后吸附量基本不变. 动力学研究结果表明, 吸附过程为液膜扩散控制过程.     

Column chromatographic boron isotope separation at 5 and 17 MPa with diluted boric acid solution

Boron isotopic fractionation factor (S) between boron taken up in strongly basic anion exchange resin and boron in aqueous solution was determined by breakthrough column chromatography at 5 and 17 MPa at 25 degrees C, using 0.1 mM boric acid solution as feed solution. The S values obtained were 1.018 and 1.012, respectively, which were smaller than the value reported by using the same chromatographic method at the atmospheric pressure at 25 degrees C with the boron concentration of 10mM, but were larger than the values under the same condition with much higher concentration of 100 and 501 mM. Calculations based on the theory of isotope distribution between two phases estimated that 21% (5 MPa) and 47% (17 MPa) of boron taken up in the resin phase was in the three-coordinated B(OH)(3)-form, instead of in the four-coordinated B(OH)(4)-form, at high pressures even with a very diluted boric acid solution. We discussed the present results by introducing (1) hydration and (2) a partial molar volume difference between isotopic molecules. Borate may have been partially dehydrated upon transfer from the solution phase to the resin phase at high pressures, which resulted in smaller S values compared with those at the atmospheric pressure. Instead, it may be possible that the difference in the isotopic partial molar volume difference between B(OH)(3) and B(OH)(4)(-) caused the S value to decrease with increasing pressure.     

有孔虫中硼的分离及其正热电离质谱法测定

针对大洋钻探计划(0DP)钻孔中有孔虫数量少、硼含量低的特点，改进了硼特效树脂和阴、阳混合离子交换树脂相结合进行分离硼的方法，成功地实现了硼的分离，并且首次采用正热电离质语法测定了有孔虫中硼同位素的比值。由于硼的分离过程不产生同位素分馏，测定结果令人满意。     

基于FIA-ISE测定WACR交换性能的研究

基于FIA-ISE测定痕量Na~+原理,建立了一种自动测定弱酸性阳离子交换树脂(WACR)交换性能的方法.本研究对WACR交换性能的各影响因素进行考察,优选出其测定条件:微型交换柱内径3.0mm、长80mm;交换反应温度33℃;树脂填充量0.1762g;样品为NaOH溶液(Na~+浓度10mg/L),流速0.92mL/min;再生剂(HCl)浓度4%,流速1.25mL/min,用量40mL.本方法实现了一次测定同时获得WACR平衡交换容量(E_q)、全交换容量(E_t)和利用率(η)等多个指标.与GB法对比,二者相关性好(r=0.9904).     

Determination of boron in water samples by chemical prompt gamma neutron activation analysis

Boron concentration has been determined in groundwater samples, collected from Khuchch, Gujarat, India, by prompt gamma neutron activation analysis (PGNAA) after selective separation and pre-concentration by solvent extraction with 10% 2-ethyl hexane 1,3-diol in CHCl₃. Solvent extraction separation helped to eliminate the interfering elements in PGNAA determination of boron. The sensitivity of PGNAA is found to be 18.83 cps/mg B based on the slope of a calibration plot obtained by carrying out measurements on synthetic boric acid samples containing boron in the range of 30–150 μg. Detection limit of the method is 0.2 μg/g counted for 35,000 seconds at a sample size of 15 gram. The precision (relative standard deviation at 1σ level) and accuracy of the method is 5%. The analytical results of the present method agreed well with well-established spectrophotometric determination of boron as boron-curcumin complex and inductively coupled plasma atomic emission spectroscopy (ICP-AES).     

A Kinetic Investigation of Chromium

A kinetic investigation was performed with an ion exchange resin for chromium. A chelating cation exchange resin (Amberlite IRC 718) was used for removal and recovery of chromium. The effect of concentration, resin amount, particle size and stirring speed on kinetics were investigated. The metal concentration range studied was between 5 to 160 mg L^–1, the resin amount range was between 5 to 20 mg, the particle size range was between 0.35 to 1.8 mm and the stirring speed range was between 1000 to 3500 rpm.Kinetic studies were done using a Kressman-Kitchener stirrer reactor system and the results were compared with existing kinetic models. Two models; Nernst-Plank film diffusion control model (fdc) and solid phase diffusion control model (pdc) were identified and the dependence of the rate on parameters, such as solution concentration, particle size, resin amount, stirring speed, etc., was examined for each of them. As a result, interpretation of these data showed that the system is probably controlled both film and particle diffusion.     

Ion Exchange Extraction of Boron from Aqueous Fluids by Amberlite IRA 743 Resin

The ion exchange characteristics d Amherlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that AmherHte IRA 743 resin, a boron specific ion exchange resin, can quantitatively extract boron as the B (OH)4- spedes from weakly basle solution. Some exchangeable anions such as CI- and SO4^2- are present, resulting in an increase in pH value of the loeded solution within the nan, and the boron in natural aqueous fluids with low nH is also extracted by Amberlite IRA 743 resin. However, the voiume of loaded solution must be restricted. The maximum voiume of loaded solution giving quantitative extraction of boron decreases for sample soh.,tiom of lower pH value. Warm HCI solution is more effective than room temperature HCI solution for eluting boron from Amberllte IRA 743 resin.     

Separation of lithium isotopes by NDOE bonded Merrifield peptide resin

The novel NDOE (1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane) ion exchange resin was prepared. The ion exchange capacity of NDOE azacrown ion exchanger was 0.2 meq/g dry resin. A study on the separation of lithium isotopes was carried out with NDOE novel azacrown ion exchange resin. The lighter isotope,⁶Li concentrated in the solution phase, while the heavier isotope,⁷Li is enriched in the resin phase. By column chromatography (0.1 cm I.D.×32 cm height) using 2.0M NH₄Cl as an eluent, a separation factor,a=1.0201 was obtained.     

Synthesis of cross-linked chitosan possessing N-methyl-d-glucamine moiety (CCTS-NMDG) for adsorption/concentration of boron in water samples and its accurate measurement by ICP-MS and ICP-AES

A chitosan resin derivatized with N-methyl-d-glucamine (CCTS-NMDG) was synthesized by using a cross-linked chitosan (CCTS) as base material. The N-methyl-d-glucamine (NMDG) moiety was attached to the amino group of CCTS through the arm of chloromethyloxirane. The adsorption behavior of 59 elements on the synthesized resin was systematically examined by using the resin packed in a mini-column, passing water samples through it and measuring the adsorbed elements in eluates by ICP-MS. The CCTS-NMDG resin shows high ability in boron sorption with the capacity of 0.61 mmol ml⁻¹ (= 2.1 mmol g⁻¹). The sorption kinetics of this resin was faster than that of the commercially available resins. Other advantages of the synthesized resin are: (1) quantitative collection of boron at neutral pH regions; (2) complete removal of large amounts of matrices; (3) no loss of efficiency over prolonged usage; (4) effective collection of boron in wide range concentration using a mini column containing 1 ml resin; (5) complete elution of boron with 1 mol l⁻¹ nitric acid. The resin was applied to the collection/concentration of boron in water samples. Boron in tap water and river water was found to be in the range of 6-8 μg l⁻¹. The limit of detection (LOD) of boron after pretreatment with CCTS-NMDG resin and measurement by ICP-MS was 0.07 μg l⁻¹ and the limit of quantification (LOQ) was 0.14 μg l⁻¹ when the volume of each sample and eluent was 10 ml.     

珊瑚中硼的分离及其同位素组成的测定

介绍了用硼特效树脂和阴、阳混合离子交换树脂相结合进行珊瑚中硼的分离和纯化方法，满足了正热电离质谱法测定硼同位素的要求，并且对几个珊瑚样品进行了硼的分离和硼同位素组成的测定，结果满意，为研究珊瑚中的硼同位素示踪古海洋环境变化提供了可能。     

Estimation of uncertainty in measurement of boron in Zr–Nb alloy samples by BF4 − ion selective electrode

Boron doped zirconium–niobium alloy is employed for neutron reactivity control in advanced nuclear reactors. An accurate knowledge of the boron content and uncertainty associated with the measurement result is essential for reactivity calculations. In view of the refractory nature of the alloy, boron determination in these matrices is a challenging task for analytical chemists. Also due to non-availability of matrix-matched reference materials, direct solid analysis cannot be resorted to. With this in view, a simple and sensitive method based on potentiometric determination of boron as tetrafluoroborate with tetrafluoroborate ion selective electrode has been developed. After dissolving the sample, boron was quantitatively converted to BF₄ ⁻ with the addition of HF. Potential response was measured with Orion 9305 BN BF₄ ⁻ ion selective electrode. The response of the ion selective electrode was Nernstian in the range of 0.1–100.0 μg/g of boron in the solution. The method has been validated by two independent methods namely spectrophotometry and inductively coupled plasma-atomic emission spectrometry (ICP-AES). All identifiable sources of uncertainties in the methodology have been individually assessed. The combined uncertainty is calculated employing uncertainty propagation law. The expanded relative uncertainty in the measurement (coverage factor 2) is 6.50%.     

Urethane modified boron filled polyesteramide: a novel anti-microbial polymer from a sustainable resource

Boron filled soybean oil based polyesteramide (BPEA) was synthesized. It was further modified through a reaction with tolylene-2,4-di-isocyanate (TDI) to obtain boron filled polyesteramide urethane (BPEAU) with different loadings of urethane. The structures of BPEA and BPEAU polymers were confirmed by FT-IR, ¹H NMR and ¹³C NMR spectroscopies. The physico-chemical characterization, viz., hydroxyl value, iodine value, acid value, refractive index and inherent viscosity was carried out by standard methods. Anti-bacterial and anti-fungal activities of these polymers were investigated by the measurement of the size and clarity of the zone of inhibition in nutrient media. All compositions of BPEAU resin were found to inhibit microbial growth while the resin with 8% urethane loading (BPEAU-8) showed the highest anti-microbial activity. The BPEAU resin can, therefore, be used as an anti-fungal and anti-bacterial coating material.     

Analysis of streptokinase by validated liquid chromatography methods and correlation with an in vitro bioassay

Reversed‐phase and size‐exclusion liquid chromatography methods were validated for the assessment of streptokinase. The reversed‐phase method was carried out on a Jupiter C₄ column (250 mm × 4.6 mm id) maintained at 25°C. The mobile phase consisted of 50 mM sodium sulfate solution pH 7.0 and methanol (90:10, v/v), run isocratically at a flow rate of 0.8 mL/min. The size‐exclusion method was carried out on a Protein KW 802.5 column (300 mm × 8.0 mm id), at 25°C. The mobile phase consisted of 40 mM sodium acetate solution pH 7.0, run isocratically at a flow rate of 1.0 mL/min. Retention times were 19.3 min, and 14.1 min, and calibration curves were linear over the concentration range of 0.25–250 μg/mL (25.75–25 750 IU/mL) (r ² = 0.9997) and 5–80 μg/mL (515–8240 IU/mL) (r ² = 0.9996), respectively, for reversed‐phase and size exclusion, with detection at 220 and 204 nm. Chromatographic methods were employed in conjunction with the in vitro bioassay for the content/potency assessment of Streptokinase, contributing to improve the quality control and ensure the efficacy of the biotherapeutic.     

Determination of ultratrace boron concentrations in uranium oxide by isotope dilution-thermal ionization mass spectrometry using a simplified separation procedure

Boron was determined at sub-ppm levels in uranium oxide by ID-TIMS. Following nitric acid dissolution, a solvent extraction method was adapted for extraction of boron by 5% 2-ethylhexane-1,3-diol in chloroform followed by evaporation of the extractant in presence of sodium carbonate and mannitol. This procedure allowed TIMS analysis of boron by monitoring the Na₂BO ₂ ⁺ ions formed from the sodium borate salt in the ion source. Reproducibility of about 1% was obtained for boron determination in the three different uranium oxide samples containing sub-ppm amounts of boron.     

流动注射离子选择电极法自动测定阳离子交换树脂交换容量的研究

基于流动注射离子选择电极法(FIA-ISE)测定痕量Na 原理,建立了一种能自动测定阳离子交换树脂各种交换性能的方法,对影响阳阳离子交换树脂交换容量的各种因素进行考察,筛选出凝胶型强阳离子交换树脂(SACR)交换性能测定的最佳条件:微型交换柱内径3.0mm、长80mm;树脂填充量0.1951g;再生剂HCl浓度为3.0%,其流速为0.90mL/min(7.64m/h),再生剂耗量350mL/g(干树脂);样品为20mg/LNa 溶液,其流速为1.50mL/min;实现了一次测定同时获得SACR的工作交换容量、平衡交换容量、全交换容量、交换速率和树脂利用率。与ASTM法进行对照实验,其结果相关性良好(r=0.9922)。     

微色谱柱分离/ICP-AES测定环境样品中的痕量硼

本文采用色谱系统对水样品（温泉水、卤水）中的硼进行分离富集，探讨了影响其分离富集的条件。实验表明，在pH＝8条件下，硼可被树脂完全吸附，用3mL 1mol/L硫酸可以从吸附术上完全解吸硼，浓缩物用ICP－AES进行测定，所建立的方法简便、准确，适合于含盐量高及其它水样品中微量硼的测定。     

Pilot‐scale ion‐exchange centrifugal partition chromatography: Purification of sinalbin from white mustard seeds

The purification of p‐hydroxybenzylglucosinolate (sinalbin) on a multigram scale from a crude aqueous extract of white mustard seeds (Sinapis alba var. concerta) was successfully achieved by scaling up a strong ion‐exchange centrifugal partition chromatography (SIXCPC) laboratory procedure. Thus, the one‐step sinalbin purification was performed with 2.35 g of crude extract in ?170 min (830 mg/h) up to 70.3 g in ?160 min (26.3 g/h) by switching from a 200 mL laboratory scale column to a 5.7 L pilot‐scale column. The required biphasic solvent system contained ethyl acetate, n‐butanol, and water in 3:2:5 v/v/v proportions, Aliquat 336® (trioctylmethyl ammonium chloride) was added to the organic stationary phase (80 mM) and acted as ion‐exchanger. Potassium iodide in the aqueous mobile phase (80 mM) was used as sinalbin displacer. The 28.5 mass scale factor arose from the increase in mobile phase flow‐rate (from 2 to 50 mL/min), from the higher mass of injected white mustard seed extract (from 12 to 350 g), and from the calculated productivity (from 830 mg to 26.3 g). These results demonstrate that industry scale production of glucosinolates is easily performed by SIXCPC, thus providing pure reference standards for pharmacology studies.     

Ion-isotopic exchange reaction kinetics using organic base anion exchange resins Indion-102 and Indion GS-400

The present study deals with the kinetic study of iodide and bromide ion-isotopic exchange reactions in organic based anion exchange resins Indion-102 (nuclear grade) and Indion GS-400 (non-nuclear grade) using radiotracer isotopes. The resins in iodide and bromide form were equilibrated respectively with iodide and bromide ion solutions which were previously spiked with ¹³¹I and ⁸²Br radiotracer isotopes. For both bromide and iodide ion-isotopic exchange reactions, it was observed that the values of specific reaction rate increase with increase in ion concentration from 0.001 to 0.004 M at a constant temperature of 40.0°C. However, at constant ion concentration of 0.003 M, the specific reaction rate was observed to decrease with rise in temperature from 30.0 to 45.0°C. Also it was observed that for iodide ion-isotopic exchange reaction by using Indion-102 resin, the values of specific reaction rate, amount of iodide ion exchanged, initial rate of iodide ion exchange and logK _d were 0.258 min^?1, 0.492 mmol, 0.127 mmol/min and 19.2, respectively, which were higher than 0.208 min^?1, 0.416 mmol, 0.087 mmol/min and 17.6, respectively, obtained by using Indion GS-400 resin under identical experimental conditions of 40.0°C, 1.000 g of ion exchange resin and 0.003M labeled iodide ion solution. The same trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that, under identical experimental conditions, Indion-102 resin shows higher performance than Indion GS-400 resin.