Adsorption isotherm and kinetic modeling of a novel procedure for physical modification of silica gel using aqueous solutions of 4,4′-(1,2-ethanediyldinitrilo)bis-(2-pentanone) for preconcentration of Ni(II) ion

ABSTRACT

Aqueous solutions of 4,4′-(1,2-ethanediyldinitrilo)bis-(2-pentanone) (EDDBP) have been used in a novel green procedure for the physical modification of silica gel (SG) for solid-phase extraction and preconcentration of Ni(II) ion. Optimization experiments were carried out at 301 ± 1 K by batch technique. The EDDBP-modified SG was characterized using X-ray Diffraction Spectroscopy (XRD) and Brunaeur-Emmett-Teller (BET) determinations. The adsorption isotherm and kinetic models indicated a physisorption process. The modified SG showed moderate to high adsorption capacity values for Ni(II) ion (~98% removal efficiency) at pH 8. A sorption mechanism for Ni(II) chelation with EDDBP-modified-SG was proposed. These results suggest the procedure has advantages.     

螯合树脂分离富集—电感耦合等离子体质谱法测定矿石中铂、钯

研究了LCS-200硫脲型螯合树脂对Pt、Pd的吸附性能,采用ICP-MS同时测定矿石中Pt、Pd。实验探讨了介质、酸度、树脂粒度、树脂用量、吸附方式及其他元素干扰等对Pt、Pd吸附效果的影响,并确定了仪器的最佳测试条件。该方法检出限Pt为0.1 ng/g、Pd为0.12 ng/g,测定国家一级标准样品中的Pt、Pd,其结果与标准值相符,相对标准偏差(RSD)Pt为3.8%～4.5%、Pd为4.1%～5.2%。该方法适用于矿石中Pt、Pd的测定。     

γ-氯丙基三乙氧基硅烷改性纳米Si-HAP分离富集-火焰原子吸收光谱测定水样中痕量的锰、钴、镍

目的建立γ-氯丙基三乙氧基硅烷改性纳米Si-HAP分离富集-火焰原子吸收法测定痕量锰、钴、镍的新方法。方法研究γ-氯丙基三乙氧基硅烷改性纳米Si-HAP在不同p H、吸附温度和时间、洗脱条件及共存离子对锰、钴、镍分离富集的影响。结果在最佳吸附条件下,该方法检出限分别为锰0.21μg/L,钴0.18μg/L,镍0.24μg/L,相对标准偏差分别为锰0.90%(1μg/mL),钴0.78%(2μg/mL),镍0.18%(5μg/mL)(n=11),样品加标回收率在95.0%~108.0%之间。结论该方法适用于水样中痕量锰、钴、镍的测定。     

Two-Directional Immunoelectrophoresis: Technique and Applications in the Clinical Laboratory

Abstract

Some recent applications of “crossed electrophoresis” (also called “electro-immunodiffusion” and “rocket electrophoresis”) are reviewed, particularly in the clinical laboratory.     

Cloud Point Extraction and Preconcentration for the Determination of Cu and Ni in Natural Water by Flame Atomic Absorption Spectrometry

Abstract

In this work, a new cloud point extraction (CPE) method was developed for the separation and preconcentration of copper and nickel. The analyte was complexed with 3‐[(8‐{[(E)‐2‐hydroxyimino‐1‐methylpropylidene] amino}‐1‐naphthyl) imino]‐2‐butanone oxime (H₂mdo) in the initial aqueous solution and octylphenoxy polyethoxy ethanol (Triton X‐114) was added as a surfactant. After phase separation, based on the cloud point in the mixture, and dilution of the surfactant‐rich phase with methanol containing 0.1 mol l^?1 HNO₃, the enriched analytes were determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions (i.e. pH=8.5, H₂mdo=3×10^?4 mol l^?1, Triton X‐114=0.1% (w/v)) the enhancement factors of 65 and 59 and detection limits of 0.14 and 0.2 ng ml^?1 were obtained for copper and nickel respectively. The proposed method was applied to the determination of copper and nickel in several natural water samples with satisfactory results.     

浊点萃取火焰原子吸收法测定水样中痕量铅的研究

以浊点革取-火焰原子吸收光谱法测定痕量铅，探讨了实验条件对浊点草取及测定灵敏度的影响。在最佳条件下，铅富集倍数达到20倍。该方法可用于自来水、井水及河水中痕量铅的测定。     

包头铁矿石中痕量铀的测定

采用碳酸钠沉淀、P350萃淋树脂微色谱柱联合分离的方法,测定铁矿石中痕量铀的含量.首先用碳酸钠将样品溶液沉淀除去大量的铁,再用P350微色谱柱分离富集痕量铀,以4 g/L氟化钠溶液洗脱,偶氮氯膦Ⅲ光度法测定铁矿石中痕量铀的含量.通过研究铁和铀分离的条件,在最佳分离条件下,铁的分离效率达99.9%,能有效地消除样品中大量铁的干扰并富集痕量铀.经包头铁矿样品验证,分析结果接近标准样品参考值,通过标准加入法获得的回收率为98.6%～101.4%.     

酒钢桦树沟铁矿石智能分选机预选抛废试验研究

采用X射线透射智能分选技术对酒钢桦树沟铁矿石进行预选抛废处理,结果表明,抛废率13%左右时,能够取得尾矿品位小于10%、铁回收率大于96%、预选粗精矿铁品位提高3.6个百分点以上的指标,试验结果稳定、数据可再现,说明利用该智能分选机可以实现酒钢镜铁山桦树沟铁矿石的有效预选抛废、提高铁矿石输出品位。     

铅的富集与快速检测

对铅的各种分离富集方法进行了分析研究,改进了碘乙醇－醋酸铵处理汽油有机铅的方法,适宜现场测定汽油中铅,该方法快速,简单,效果好。