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。     

浊点萃取-石墨炉原子吸收测定自来水样中的铁

建立了一种用于环境水样中痕量铁元素测定的方法。该方法通过浊点萃取对环境水样中痕量铁进行预富集分离,并与石墨炉原子吸收分光光度法联用进行检测,在最优化条件下,测定水中的痕量铁,RSD为2．06％,检测限为1．2×10^-2μg／L。     

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.     

Micelle-Mediated Extraction and Cloud Point Preconcentration of Chlorophylls from Spinach

A micelle-mediated extraction and cloud point preconcentration of chlorophylls method was developed. Non-ionic surfactant (Genapol X-080) was employed as an alternative and effective extraction solvent. The optimal extraction parameters based on the micelle extraction technique were determined. Under optimal conditions, i.e., 5% Genapol X-080 (v/v), pH 9.0, liquid/solid ratio of 10:1 (mL g^?1), ultrasonic-assisted extraction for 30 min, extraction amount reached the highest value. For the preconcentration of chlorophylls by cloud point extraction (CPE), the solution was incubated at 50° for 30 min, and 0.1 g mL^?1 sodium chloride was added to the solution to facilitate the phase separation. The microstructure of coacervate phase after CPE was explored with transmitting electron microscopy. The preconcentration factor for chlorophylls was about 12.5, the extraction recovery approached 99.2%, and the loading capacity was about 1 mg mL^?1. Thus coupling of ultrasonic-assisted micelle extraction and cloud point extraction could be employed as a new and effective technique for the rapid extraction and preconcentration of chlorophylls from plants such as spinach.     

浊点萃取技术在环境样品分析中的应用

浊点萃取技术(CPE)是近年来提出的一种新型的液-液、液-固萃取分离提取技术,是将表面活性剂应用于分析化学领域的一种重要而实用的技术,具有萃取效率高、富集因子大、操作简便、安全、无需大量有机溶剂等优点。适用于环境样品中金属离子及痕量有机污染物的分析。本文主要介绍了CPE技术在环境样品分析中的应用,且探讨了该技术的发展前景。     

Cloud Point Extraction of Four Triphenylmethane Dyes by Triton X-114 as Nonionic Surfactant

A method for removing four triphenylmethane dyes from wastewater by cloud point extraction with the nonionic surfactant Triton X-114 (TX-114) was developed. The triphenylmethane dyes were crystal violet, ethyl violet, malachite green and brilliant green. The cloud point of TX-114 generally increased in the presence of any of the four dyes. In the cloud point system, these dyes were solubilized into a coacervate phase that left a color-free dilute phase. The extraction efficiency of the dyes increased with the temperature, TX-114 concentration, and salt (NaCl and CaCl₂) concentration. More than 97% TX-114 in the dilute phase was recovered by adjusting the volume ratio of dichloromethane to the dilute phase. The Langmuir-type adsorption isotherm was used to describe the dye solubilization. The Langmuir constants m and n were calculated as functions of temperature. The results showed that the solubilization of the triphenylmethane dyes in the cloud point system was related to the partition coefficient and their molecular structures.     

原子吸收光谱法测定水样中铁含量的不确定度评定

采用火焰原子吸收光谱法对水样中铁的含量进行测定,分析测量过程中不确定度来源及各不确定度分量对总不确定度的影响,确定测定结果的置信区间。给出本实验室测定水样中铁含量的扩展不确定度为0.087mg/L(Veff=10)。     

浊点萃取-原子吸收法测定水中微量的镉

基于5-Br-PADAP与镉形成稳定的螯合物能被TritonX-114浊点萃取的事实,建立了浊点萃取-原子吸收法测定水中微量的镉的新方法。镉的浓度在0.25～4.00μg/mL内呈线性,检测限为6.7μg/L;相对标准偏差（n=11）为2.7%,加标回收率为98.5%～102.3%。     

火焰原子吸收光谱法测定铜及铜合金中铁量

试样用硝酸、盐酸和过氧化氢溶解,于原子吸收光谱仪波长248.3 nm处用空气-乙炔贫燃型火焰进行铁量的测定。     

浊点萃取-原子吸收法测定水中微量的铅

基于5-Br-PADAP与铅形成稳定的螯合物能被TritonX-114浊点萃取的事实,建立了浊点萃取-原子吸收法测定水中微量的铅的新方法。铅的浓度在0~30μg/mL内呈线性,检测限为1.7 ng/mL;相对标准偏差（n=11）为2.7%,加标回收率为97.5%~102.5%。     

火焰原子吸收光谱法测定牛奶中铁和锌

先将牛奶碳化,再用酸溶解,利用TritonX-100使测定铁、锌的灵敏度分别提高8．3％、16．4％,且有效地消除了牛奶中存在的其他金属离子的干扰。该方法简单、快速、准确。     

火焰原子吸收分光光度法测定蔬菜中铜锌铅

蔬菜经过处理之后,在选定条件下,应用火焰原子吸收分光光度法同时测定蔬菜中铜、锌、铅的含量,方法简便、快速.三种元素的含量分别为0.5128 mg/Kg、0.8023mg/Kg、0.1028 mg/Kg,精密度RSD小于1.4%,加标回收率在92.3%～97.2%之间,结果令人满意.     

离子液体萃取-火焰原子吸收光谱法测定痕量铜

以N-正丁烷基苯并噻唑六氟磷酸盐温敏性离子液体为萃取剂,乙腈为分散剂,萃取富集痕量铜离子,用火焰原子吸收法测定,建立了一种快速、简便分析铜离子的新方法。考察了离子液体的浓度、冰浴时间、溶液p H、萃取温度、萃取时间等对萃取率的影响。结果表明,方法检出限为0.18μg/L,相对标准偏差(RSD)为1.09%;对矿泉水和绿茶中铜离子进行分别检测,加标回收率为98.5%~105.1%。     

Determination of Iron and Copper in Edible Oils by Flame Atomic Absorption Spectrometry After Liquid–Liquid Extraction

In the present work, a novel and rapid extraction method for Fe(III) and Cu(II) from liquid edible oils is described. N,N′‐Bis(4‐methoxysalicylidene)‐1,2‐diamino ethane (MSE) was utilized for the extraction of metal ions and the determination was achieved by flame atomic absorption spectrometry (FAAS). In order to optimize the extraction conditions, a central composite design (CCD) technique was employed. The optimum conditions, the ratio of MSE solution volume to oil mass, stirring time and temperature, were determined as 1.2 and 1.1 mL g^?1; 24.0 and 31.8 min and 25.3 and 33.2 °C for Fe(III) and Cu(II) extraction, respectively. The feasibility of the improved method was tested with oil‐based metal standards affording 98.6 % recovery for both metals and 67.3 ng g^?1 for Fe(III) and 15.3 ng g^?1 for Cu(II) as limit of detection (LOD).     

Extraction of Zinc,Copper, and Lead Ions with a Zeolite Loaded by a Multidentate Schiff Base Ligand Followed by Flame Atomic Absorption Spectrometric Analysis

A multi-element preconcentration–separation technique for metal ions is established. The procedure is based on complex formation of metal ions with Bis(2-hydroxy-1-naphtaldimine)-N-diethylentriamine (BHNDT) on nanoporous Analcime as sorbent followed by their determination using flame atomic absorption spectrometry. The effects of analytical parameters like pH, flow rates, eluent types, and sorption capacity on the recoveries of metal ions are investigated. In order to predict the extraction ability of BHNDT for different metallic ions, DFT method is used to compute the binding energies of the cations to the title Schiff base compound. The calculated binding energies are in good agreement with the observed extraction power of the Shiff-base ligand.     

微波辐射下空气氧化法合成2-(对甲氧基苯基)苯并咪唑

首次在微波辐射下无催化剂空气直接氧化合成了2-(对甲氧基苯基)苯并咪唑,考察了微波辐射功率、辐射时间、原料配比、溶剂用量对产率的影响.实验表明:当微波辐射功率为280W,辐射时间为5.0min,n(对甲氧基苯甲醛):n(邻苯二胺)=1.1:1.0,乙醇用量为6.0mL时,产率可达88.7％.     

浊点萃取-高效液相色谱法测定某些中草药中铜的研究

基于浊点现象,建立了以双硫腙为配位剂、TritonX-114为表面活性剂的浊点萃取-高效液相色谱法测定中草药中痕量铜的新方法。研究了溶液pH值、配位剂的浓度、表面活性剂的浓度、平衡温度和平衡时间、流动相类型等实验条件对浊点萃取及铜测定的影响。在最佳试验条件下,该方法的线性范围为0．1—120μg·L^-1,相关系数达0．997-0．999,铜的检出限达到0．1μg·L^-1。相对于传统的液相色谱分析法灵敏度提高了18倍。该方法成功用于中草药样品中铜的测定并获得了满意的结果。     

OP乳化剂进样火焰原子吸收光度法对微量锌、铁的测定

研究了表面活性剂及微乳液对火焰原子吸收光度法测定锌,铁的增敏作用。并选择增敏作用较好的OP乳化剂作用锌,铁测定的增敏试剂,该方法快速简便,结果准确。     

一次溶样原子吸收光谱法检测地质样品银、铜、铅、锌的方法研究

通过实验探讨了一次溶样原子吸收光谱法检测地质样品中银、铜、铅、锌的有关问题的方法研究,改变了原来的分别溶样定容即操作繁琐浪费资源又延长了周期,而是采用一次王水溶样定容,达到了降低成本、简便、快速、准确的宗旨。     

Cloud Point Extraction and Pre-Concentration of Four Alkaloids in Nelumbo nucifera Leaves by Ultrahigh Pressure-Assisted Extraction

A rapid micellar extraction and pre-concentration method by ultrahigh pressure-assisted was developed for four alkaloids in Nelumbo nucifera leaves. Nonionic surfactant polyoxyethylene octylphenol ether (OP-10) solution was selected as solvent. Various experimental conditions were investigated to optimize the extraction and pre-concentration process. The optimal UPE condition was 5% OP-10 (w/w) solution, 400 MPa of pressure, 1 min of extraction time, and 1:20 (g/mL) of solid/liquid ratio. The pre-concentration of alkaloids was achieved by cloud-point extraction (CPE) and the optimum CPE condition was incubated in a thermostatic water bath at 55°C for 10 min, with 10% OP-10 and 15% sodium chloride added into the solution. The pre-concentration factor (CF) value was 11.6 ± 0.127, and the CPE recoveries for O-nornuciferine, N-nornuciferine, nuciferine, and roemerine were 91.0%, 92.3%, 92.7%, and 94.5%, respectively.