用1-亚硝基-2-萘酚修饰的微晶蒽分离富集与测定环境水中钴

建立了微晶蒽分离富集环境水样中痕量Co(II)的方法。在pH3.0条件下,1-亚硝基-2-萘酚与Co(II)形成红棕色螯合物被微晶蒽定量吸附,能使Co(II)与Pb(II)、Ni(II)、Mn(II)、Cu(II)、Cd(II)、Zn(II)、Fe(III)、Cr(III)、Al(III)等常见离子分离。本法富集倍数达100倍,检出限为0.14μg/L,回收率97.5%～105%,已应用于不同水样中Co(II)的测定。     

负载乙基紫的微晶酚酞吸附富集-分光光度法测定水中痕量钒

建立了以微晶酚酞作为吸附剂分离富集环境水样中痕量钒的新方法。研究表明,当pH值在3.7～7.0时,溶液中以V3O39-存在形式为主的钒,与乙基紫阳离子(EV )形成的离子缔合物(V3O93-).(EV )3能被微晶酚酞定量吸附,在钒被富集的同时并能使其与常见阳离子Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)、Al(Ⅲ)、Cu(Ⅱ)、Hg(Ⅱ)、Pb(Ⅱ)、Mn(Ⅱ)、Fe(Ⅲ)、Cr(Ⅲ)等完全分离,且基本不受能与EV 形成离子缔合物的阴离子SO24-、NO3-、Br-、Cl-、I-、ClO4-的影响。分别在1.0L不同环境水样中加入5.00mL1.0×10-3mol/LEV 及1.0mL0.10mol/LHCl(调溶液pH值约为4.0)和5.00mL15.8%的酚酞乙醇溶液,搅拌约50min,能够使水样中的痕量钒得到很好的富集。富集因数达100～200倍,回收率在98.0%以上,RSD为1.1%～2.3%。     

微晶酚酞分离富集分光光度法测定铊(Ⅲ)

建立了利用无毒的微晶酚酞作为固相萃取剂分离富集溶液中痕量Tl(Ⅲ)的方法。在H3PO4介质中,Tl(Ⅲ)在水相中与I-和结晶紫(CV+)形成离子缔合物而被微晶酚酞定量吸附,富集后的Tl(Ⅲ)可直接用光度法测定。控制一定的条件,Tl(Ⅲ)能与常见离子Na+,K+,Al3+,Cu2+,Pb2+,Zn2+,Ba2+,Mn2+,Ca2+,Cd2+,Fe2+等完全分离,且基本不受Cl-,Br-,SO42-,NO3-等阴离子的影响。方法可直接应用于环境水样中痕量Tl3+的测定,富集倍数可达100倍,回收率95.6%~101.8%,检出限为13 ng/L。     

负载十四烷基二甲基苄基铵的微晶三苯甲烷分离富集痕量Cu(Ⅱ)

在SCN-存在下,Cu(Ⅱ)与SCN-形成的Cu(SCN)42-可被吸附在负载氯化十四烷基苄基铵(Zeph)的微晶三苯甲烷(TPM)上。在最佳条件下,Cu(Ⅱ)能与常见阳离子Fe(Ⅲ)、Ni(Ⅱ)、Cr(Ⅲ)、Al(Ⅲ)、Mn(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)等完全分离,且富集时基本不受SO24-、NO3-、SCN-、Br-、Cl-、ClO4-的影响。富集因子可达100倍,回收率在91%以上。该方法已成功用于环境水样中Cu(Ⅱ)的富集与测定。     

甲基紫修饰的微晶酚酞分离富集-光度法测定痕量铋(Ⅲ)的研究

建立了以修饰有甲基紫(MV)的微晶酚酞作为固相吸附剂分离富集和测定环境样品中痕量Bi(Ⅲ)的新方法.研究表明,Bi(Ⅲ)与I-、 MV 形成三元离子缔合物[BiI6] (MV)3能定量吸附在微晶酚酞上,在适当条件下,Bi(Ⅲ)能与Co(Ⅱ)、 Ni(Ⅱ)、 Mn(Ⅱ)、 Fe(Ⅱ)、 Al(Ⅲ)、 Zn(Ⅱ)等常见阳离子分离,且基本不受Br-、 SCN-、 SO42-、 NO3-、 Cl-、 ClO4-等阴离子影响.Bi(Ⅲ)的静态吸附容量为0.81 mmol/g,富集因数可达200倍,回收率在97.2%以上,RSD 1.3%～2.2%之间.已应用于环境水样中Bi(Ⅲ)的测定.     

微晶酚酞预富集-分光光度法测定痕量Co(Ⅱ)

建立了一种以微晶酚酞作为固态吸附剂对样品中痕量的Co（Ⅱ）分离富集的新方法，富集后的co（Ⅱ）可直接用光度法测定。控制一定条件，Co（Ⅱ）能与常见阳离子Ni（Ⅱ）、Cd（Ⅱ）、Al（Ⅲ）、Ca（Ⅱ）、Mg（Ⅱ）、Pb（Ⅱ）、Mn（Ⅱ）、Fe（Ⅲ）、Bi（Ⅲ）等完全分离，且富集时基本不受SO4^2-、NO3^-、Br^-、Cl^-、I^-等阴离子影响。微晶酚酞对Co（Ⅱ）的吸附容量为23．5mg／g；富集因数可达200倍，回收率在97．6％以上，RSD为1．1％～2．3％。已用于环境水样及日常用水中Co（Ⅱ）的富集测定。     

苯甲酰偶氮间苯二酚氨丙基键合硅胶的制备及其富集、分离痕量元素的研究

本文介绍了苯甲酰偶氮间苯二酚氨丙基键合硅胶(BARA·SG)的合成方法,研究了BARA·SG的性质及其对痕量元素的富集和分离。结果表明:BARA·SG在6mol/L HCl～pH9.0的溶液中稳定;对Cu(Ⅱ)的最大吸附量为26.3μmol/g。在pn5.0时,经BARA·SG柱预富集处理后,可测定水样中ng/g级的Cu(Ⅱ);调节溶液的pH为2.7,痕量UO_2(Ⅱ)、Pd(Ⅱ)、Pt(Ⅳ)可与常见过渡金属离子、稀土金属离子直接柱上分离;采用分步洗脱方法,可将UO_2(Ⅱ)与Pd(Ⅱ)、UO_2(Ⅱ)与Pt(Ⅳ)分离。色层柱可重复使用多次,用普通分光光度法测定痕量元素的下限可达ng/g级。     

双波长双指示剂催化光度法同时测定Fe和Cu

研究了在Na2SO4介质中,痕量Fe(Ⅲ)和Cu(Ⅱ)催化H2O2氧化次甲基蓝和甲基橙褪色的指示反应,通过测量440和664 nm波长下,催化反应体系和非催化反应体系的吸光度,建立了双波长、双指示剂催化动力学光度法同时测定痕量Fe(Ⅲ)和Cu(Ⅱ)的新方法.同时测定Fe(Ⅲ)和Cu(Ⅱ)的线性范围分别为0.0050～0.50 μg/25 mL和0.0025～0.75 μg/25 mL,检出限分别为6.9×10-8 g/L和8.7×10-8 g/L.用于水样中痕量Fe(Ⅲ)和Cu(Ⅱ)的测定.     

氨丙基硅三烷改性介孔二氧化硅及对痕量镉(Ⅱ)的分离富集性能研究

以氨丙基硅三烷作为改性剂,对介孔二氧化硅表面进行修饰,制备了氨基化介孔二氧化硅吸附材料,采用透射电镜和傅立叶红外光谱仪对其进行表征,并用于水样中痕量镉的富集,建立了氨基化介孔二氧化硅分离预富集/火焰原子吸收光谱法测定痕量镉的方法。考察了溶液pH值、样品流速、洗脱剂类型、干扰离子和吸附容量等对痕量镉分离富集的影响,以及该吸附材料对痕量镉(Ⅱ)的吸附性能。结果表明,溶液pH 7.0,样品流速8 m L/min时镉离子能被制备材料高效吸附,吸附的镉(Ⅱ)用5.0 m L 2 mol/L HNO_3完全洗脱,火焰原子吸收法测定。在最佳实验条件下,方法的线性范围为0.6~20 ng/m L,定量下限为0.5 ng/m L,富集倍数为50倍,对10 ng/m L Cd2+测定的相对标准偏差(n=11)为0.92%,加标回收率为98.8%~104.5%。该方法的抗干扰能力较好,富集柱可循环使用12次以上,可用于环境水样中镉(Ⅱ)的测定。     

活性炭吸附及离子交换富集分离-分光光度法测定水中痕量银

建立了用活性炭对水中痕量银进行预富集的新方法。结果表明,pH=1.0时,活性炭能对水中被抗坏血酸还原后的痕量银进行吸附富集,而Cu(Ⅱ)、Fe(Ⅲ)、Co(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)、Mn(Ⅱ)、Al(Ⅲ)、Bi(Ⅲ)和Sb(Ⅲ)等常见阳离子不被吸附,用K2S2O8将吸附在活性炭上的单质银氧化解脱后,用Mg(NO3)2辅助置换洗脱,可用分光光度法测定。该法在8～50μg/L银(Ⅰ)范围内加标回收率为93.2～97.1%。同时还研究了活性炭对银的吸附行为,提出了活性炭表面上被氧化的Ag(Ⅰ)和Mg(Ⅱ)有离子交换作用。应用该法测定自来水中痕量银,结果令人满意。     

Kinetic and Thermodynamic Investigations of Zn(II) Adsorption on Microcrystalline Anthracene Modified with 8‐Hydroxyquinoline and Its Application to the Preconcentration and Determination of Trace Zinc

A new method that utilizes microcrystalline anthracene modified with 8‐hydroxyquinoline as an adsorbent has been developed for the preconcentration of trace Zinc(II). The possible reaction mechanism is discussed in detail. The influences of different parameters, such as acidity, other metal ions, the amounts of 8‐hydroxyquinoline and anthracene, etc. on the enrichment yield of Zn(II) have been studied to optimize the experimental conditions. The experimental data were fitted well with the pseudo‐second‐order kinetic model and Langmuir model at all studied temperatures and the maximum adsorption capacity was 32.58 mg·g^?1 (300 K). The thermodynamic parameters (ΔG^θ, ΔH^θ and ΔS^θ) showed the feasibility, exothermic and spontaneous nature of the adsorption at 280～320 K. Experiments indicate that Zn(II) can be completely separated from Cu(II), Co(II), Cd(II), Mn(II), Ni(II) in the eluent. The recovery of this method is in the range of 96.0%～105.0% with preconcentration factor of 100 and the limit of detection after preconcentration is 0.068 μg·L^?1. The proposed method has been successfully applied to the determination of trace Zn(II) in effluents and synthetic water sample having a composition similar to certified water sample SLRS‐4 (NRC, Canada). Analytical results obtained by this recommended method were very satisfactory.     

Study on Preconcentration of Trace Copper Using Microcrystalline Triphenylmethane Loaded with Malachite Green

The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry （FAAS）. Under the optimum conditions, Cu（Ⅱ） can be totally adsorbed on the surface of microcrystalline triphenylmethane, and completely separated from Pb（Ⅱ）, Cd（Ⅱ）, Co（Ⅱ）, Cr（Ⅲ）, Ni（Ⅱ）, Mn（Ⅱ）, Fe（Ⅲ） and Al（Ⅲ） by controlling acidity. The preconcentration factor of this proposed method is 200. The recovery is in a range of 97.5%-105%. The relative standard deviation （RSD） is not beyond 3.0%. The proposed method has been successfully applied to the determination of trace copper in various water samples with satisfactory results.     

A novel method of the separation/preconcentration and determination of trace molybdenum(VI) in water samples using microcrystalline triphenylmethane loaded with salicyl fluorone

It is the first time that triphenylmethane was used as an adsorbent to preconcentrate and separate trace amount of molybdenum in water samples. The effects of different parameters, such as acidity, stirring time and various metal ions, the amounts of triphenylmethane and salicyl fluorine, etc. on the enrichment yield of molybdenum have been studied to optimize the experimental conditions. Under the optimum conditions, molybdenum can be adsorbed on the surface of microcrystalline triphenylmethane loaded with salicyl fluorone by the intermolecular action strength. The possible reaction mechanism for the enrichment of molybdenum was discussed in detail in this paper. Mo(VI) can be completely separated from Pb(II), Co(II), Cu(II), Cr(III), Ni(II), Hg(II), Zn(II), Cd(II), Fe(III) and Al(III) in the solution. The proposed method was successfully applied to the determination of trace amount of molybdenum in various water samples by spectrophotometry after preconcentration using microcrystalline triphenylmethane. The preconcentration factor is from 83 (500 ml water sample was enriched to 6.0 ml) to 166 (1000 ml water sample was enriched to 6.0 ml). The detection limit is 1.3 × 10⁻⁵ mg l⁻¹ and the linearity is maintained in the concentration range 3.8 × 10⁻³ to 0.36 mg l⁻¹ with a correlation coefficient of 0.9998. The recoveries are in the range of 93.5-104%. The relative standard deviation is 1.8-2.9%. Analytical results obtained with this novel method are very satisfactory.     

Determination of Copper by Faas After Preconcentration with Lead-4-Methylpiperidinedithiocarbamate on Microcrystalline Naphthalene By Solid Phase Extraction

ABSTRACT

By using the Pb-4-methylpiperidinedithiocarbamate complex (Pb(4-MPDC)₂) on microcrystalline naphthalene in a column a method was developed for the preconcentration of copper in water samples prior to its determination by FAAS. In this method, copper in liquid phase quantitatively replaces lead on the Pb(4-MPDC)₂-naphthalene solid phase in the column, forming solid Cu(4-MPDC)₂ complex.

Afterwards, copper on Cu(4-MPDC)₂-naphthalene can be easily eluted by potassium cyanide into the aqueous phase, and the Cu is measured by FAAS. The optimum experimental parameters such as pH, flow rate, sample volume, Pb(4-MPDC)₂-naphthalene ratio, concentration of the potassium cyanide solution and effect of matrix ions for the preconcentration of copper were investigated. The obtained recovery was nearly 100 %, when the enrichment factor was 100 for standard solutions and spiked water samples. The proposed method has been employed for the determination of copper in various standard metal alloys and natural water samples.     

微晶酚酞富集-分光光度法测定痕量Zn(II)

建立了一种利用修饰有结晶紫(CV^＋)的微晶酚酞作为固态吸附剂分离富集溶液中痕量Zn(II)的新方法, 富集后的Zn(II)含量可直接用光度法测定. 控制一定条件, Zn(II)能与常见阳离子Ni(II), Cd(II), Al(III), Ca(II), Mg(II), Co(II), Mn(II), Cu(II), Pb(II), Fe(III)等完全分离, 且富集时基本不受, , Br^－, Cl^－, I^－,等阴离子影响. 微晶酚酞对Zn(II)的吸附容量为25.8 mg/g; 富集因数可达200倍, 回收率在97.7%～102%之间, RSD小于2.7%. 该方法已成功应用于实际水样中Zn(II)的富集测定, 结果令人满意.     

Synthesis and Efficiency of a Spherical Macroporous Epoxy-dicyandiamide Chelate Resin for Preconcentrating and Separating Trace Au, Hg, Pd and Ru from Samples

IntroductionThe preconcentration and separation of elements in samples by means of a chelateresin[l--5J or a chelate fibre[6'7J have been reported. However, the synthesis of the resin or thefibre usually takes a long time and a complex synthetic process. Accordingly, the epoxy--tan-ning chelate resin[8] and the epoxy-urea chelate .esin[9] have been synthesized and used for thepreconcentration of trace elements. However, these chelate resins could not be used for theenrichment of trace element…     

Thioacetamide chemically immobilized on silica gel as a solid phase extractant for the extraction and preconcentration of copper(II), lead(II), and cadmium(II)

Thioacetamide immobilized on silica gel was prepared via the Mannich reaction. The extraction and enrichment of copper(II), lead(II), and cadmium(II) ions from aqueous solutions has been investigated. Conditions for effective extraction are optimized with respect to different experimental parameters in both batch and column processes prior to their determination by flame atomic absorption spectrometry (FAAS). The optimum pH ranges for quantitative adsorption are 4.0-8.0, 2.0-7.0, and 5.0-10.0 for Pb(II), Cu(II), and Cd(II), respectively. Pb(II) and Cd(II) can be desorbed with 3 mol/L and 0.1 mol/L HCl/HNO3, and Cu(II) can be desorbed with 2.5% thiourea. The adsorption capacity of the matrix has been found to be 19.76, 16.35, and 12.50 mg/g for Pb(II), Cu(II), and Cd(II), respectively, with the preconcentration factor of approximately equal to 300 for Pb(II) and approximately equal to 200 for Cu(II) and Cd(II). Analytical utility is illustrated in real aqueous samples generated from distilled water, tap water, and river water samples.     

在线固相萃取预富集-原子吸收联用测定痕量Fe(Ⅱ)和总铁量

以1,10-二氮菲(1,10-phen)为配合剂,乙醇为洗脱液,在C₁₈柱上将流动注射固相萃取预富集-原子吸收光谱联用测定痕量Fe(Ⅱ)和总铁.Fe(Ⅲ)的含量可通过抗坏血酸还原后用差示法测得.本法灵敏度高,选择性好,能在线分离干扰富集Fe(Ⅱ),采样速度80次/h,富集倍数19倍,检测下限为3μg/L,相对标准偏差1.1%(n=10),可用于测定水样中痕量Fe(Ⅱ)和Fe(Ⅲ),回收率为94%105%.     

四丁基溴化铵-KI-水体系浮选分离钯(Ⅱ)的研究

研究了四丁基溴化铵-KI体系分离钯的行为及与其他金属离子分离的条件。实验结果表明,在水溶液中,Pd(Ⅱ)与四丁基溴化铵和KI形成不溶于水的三元缔合物[PdI4][TBAB]2,此三元缔合物沉淀浮于盐水相上层形成界面清晰的液-固两相。当四丁基溴化铵和KI的浓度分别为7.0×10-4mol/L和2.0×10-3mol/L时,Pd(Ⅱ)的浮选率达到99.5%以上。而Ce(Ⅲ),Fe(Ⅱ),Sn(Ⅳ),Co(Ⅱ),Mn(Ⅱ),Rh(Ⅲ),Zn(Ⅱ),Ga(Ⅲ),Cr(Ⅲ),Mo(Ⅵ),W(Ⅵ),Ni(Ⅱ),Al(Ⅲ)和V(Ⅴ)离子在该体系中不被浮选,实现了Pd(Ⅱ)与这些金属离子的定量分离。对合成水样中Pd(Ⅱ)的分离和测定,结果满意。该方法在微量钯的分离和富集分析中有一定的实用价值。