酸性媒染紫—示波计时电位法测定天然水不同形态铝

本文报道酸性媒染紫（SVRS）一示波计时电位法测定天然水中不同形态铝。对24个实际水样分别在酸性pH5.2测定了无机单核铝Ali和碱性pH8.8底液中测定总单核铝Ala,有机单核铝Al0-Ala-Alio同时还应用该法测定了酸化水样中总铝AlT,酸溶态铝AlT=AlT-Ala,从而实现了水样中五种形态铝的电化学测定,测定值与Driscoll方法进行了比较对照,结果基本一致。本法特点为：简便快捷,灵敏准确,可以直接测定与铝毒性密切相关的无机单核铝Ali,无需分离步骤,水样用量小,适用于大批量天然水样中Al形态的快速分析。     

酸性媒染紫一示波计时电位法测定天然水不同形态铝

本文报道酸性媒染紫(SVRS)一示波计时电位法测定天然水中不同形态铝.对24个实际水样分别在酸性pH5.2测定了无机单核铝Ali和碱性pH8.8底液中测定总单核铝A1a,有机单核铝Al.=A1a-Ali.同时还应用该法测定了酸化水样中总铝AlT,酸溶态铝Alr=AlT-A1a,从而实现了水样中五种形态铝的电化学测定.测定值与DriSColl方法进行了比较对照,结果基本一致.本法特点为简便快捷,灵敏准确,可以直接测定与铝毒性密切相关的无机单核铝A1i,无需分离步骤,水样用量小,适用于大批量天然水样中Al形态的快速分析.     

铬蓝黑R-示波计时电位法快速测定天然水不同形态铝

报道了采用铬蓝黑R(EBBR)-示波计时电位法分别在酸性和碱性条件下直接检测天然水中的无机单核铝[Ali]和总单核铝[Ala]浓度.并用该法测定了酸消化水样中的总铝[AlT],由[Ala]-[Ali]间接得到有机单核[Alo],[AlT]-[Ala]得到酸溶态铝[Alr],从而实现了水中5种Al形态的电化学测定.实验条件和结果如下在碱性pH=8.0的0.5 mol*L-1 KCl+0.1 mol*L-1 Na2B4O7缓冲溶液中, EBBR切口为Ep1= -0.60 V,加入铝后出现新切口,Ep2=-1.05 V,检测线性范围为5×10-7～7×10-5 mol*L-1,检测下限为2×10-7 mol*L-1,在5× 10-6 mol*L-1 Al时相对标准偏差为4.6% (n=10).分别在酸性和碱性条件下测定了水样中的铝浓度,发现在酸性下测定的是无机单核铝,而在碱性下则是总单核铝(包括无机单核铝和有机单核铝两部分).据此实现了对铝形态的区分,测定了20多个实际水样,与Driscoll方法所获结果进行对照,结果基本一致.     

离子交换/8-羟基喹啉荧光法分别测定天然水中的无机和有机单核铝

采用离子交换／氯仿萃取－８－羟基喹啉荧光法（８－Ｏｘ－ＣＦ－ＥＦ）分别测定了天然水样中的无机和有机单核铝。与Ｄｒｉｓｃｏｌｌ建立的铝形态区分法进行了比较,结果一致,本法优点是：可以直接测定水中的无机单核铝,减少了实验误差。     

氯仿萃取8-羟基喹啉荧光法测定天然水中的总单核铝和酸溶态铝

采用氯仿萃取８－羟基喹啉荧光光度法（８－ＨＱ－ＣＬ－ＭＦ）测定了天然水样中的总单核铝和酸溶态铝含量,与Ｄｒｉｓｃｏｌｌ的甲基异丁基酮萃取８－羟基喹啉－石墨炉原子吸收法（８－ＨＱ－ＭＩＢＫ－ＧＦ／ＡＡＳ）法进行了比较,结果一致。本法具有取样量小,检测快捷,灵敏度高,重现性好等突出优点,合适于天然水中的总单核铝和酸溶态铝的分析。研究了滤膜过渡,酸消化以及紫外酸消化对天然水中铝形态测定的影响。     

阳离子交换树脂分离-铝试剂分光光度法测定土壤中铝形态

研究了铝试剂光度法测定土壤溶液中铝的最佳条件,着重探讨了共存离子,特别是土壤溶液中的无机离子和有机阴离子对测定铝的影响。采用阳离子交换树脂分离,建立了测定土壤溶液及天然水中铝形态方法。用该法可测定总反应性铝、总单核铝和稳定性单核铝。由总反应性铝减去总单核铝求得酸溶性铝。由总单核铝减去稳定单核铝求得不稳定单核铝。与阳离子树脂交换分离-邻苯二酚紫光度法进行了比较。结果表明：邻苯二酚紫光度法灵敏度较高,但铁的干扰较大。铝试剂光度法灵敏度略低,但铁的干扰较少。阳离子树脂交换分离-铝试剂光度法更适合于测定含铁量比较高的土壤溶液中的铝形态。     

铍试剂Ⅲ/钙色素双偶氮染料-示波计时电位法快速测定天然水中不同形态铝

采用铍试剂Ⅲ (简称BER)和钙色素 (简称CAL)双偶氮染料 示波计时电位法快速测定天然水中不同形态铝。实验条件和结果如下 :在pH 5 .0NH4Ac HAc缓冲溶液中 ,BER在dE dt E示波图上出现一个切口 ,Ep1 =-0 .3 5V。加入铝后出现一新切口 ,Ep2 =-0 .70V ,该切口深度与加入铝量在 1 .0× 1 0 - 6 ～ 2 .0× 1 0 - 5mol L浓度范围内呈线性关系 ;检出限为 5 .0× 1 0 - 7mol L ;在 5 .0× 1 0 - 6 mol LAl时相对标准偏差为 5 5 % (n=1 0 )。在pH 8.0NH4Ac NH3·H2 O缓冲溶液中 ,CAL在示波图上出现一个切口 ,EP′1 =-0 .60V。加入铝后出现一新切口 ,EP′2 =-0 .75V ,该切口深度与加入铝量在 1 .0×1 0 - 6 ～ 1 .0× 1 0 - 5mol L浓度范围内呈线性关系 ,检出限为 5 .0× 1 0 - 7mol L ;在 2 .0× 1 0 - 6 mol LAl时 ,相对标准偏差为 5 .5 % (n =1 0 )。分别采用两种试剂在弱酸性和弱碱性条件下测定了天然水样中的铝浓度 ,发现在弱酸性下测定的是无机单核铝 ,而在弱碱性下则是总单核铝 ,据此可以实现对 5种铝形态的区分。测定了实际天然水样 ,与Driscoll方法进行了对照 ,结果基本一致     

天然水中总碱度的自动电位滴定

过去多采用经典的中和滴定法测定水中总碱度,在分析大批试样时,劳动强度较大,且易产生误差,我们改用自动电位滴定计测定天然水中总碱度,具有淮确度高、分析速度快的优点,一个工作日可以分析32—40个水样。实验中应用ZD-2型     

氯磺酚S-示波计时电位法测定天然水中5种形态铝

铝形态;氯磺酚S-示波计时电位法测定天然水中5种形态铝     

天然水中可溶性硅酸与铝盐作用机理探讨

通过考察单核铝和溶解铝浓度的变化, 对天然水体中溶解性硅酸与铝盐的反应机理进行研究. 试验过程中, 采用8-羟基喹啉荧光分光光度法测定铝浓度并结合热力学计算进行机理验证. 结果表明: 单体硅酸和聚硅酸主要与溶液中的单核铝反应生成溶解性硅铝酸盐. 单体硅酸与单核铝的结合能力较弱; 聚硅酸与单核铝的结合能力则较强, 反应产物主要为二啮或三啮配合物. 溶液pH对反应过程有着重要影响, 偏碱性环境对硅酸与单核铝间的反应具有促进作用.     

铬蓝黑R-示波计时电位法快速测定天然水中不同形态的铝浓度

本文报道铬蓝黑 R-示波计时电位法快速测定天然水中不同形态的铝。在 0 .5mol/L 乙酸 -乙酸铵 - 1× 1 0 - 3mol/L铬蓝黑 R( p H4.6)底液中 ,铝 -铬蓝黑 R铬合物在 - 0 .80 V电位处产生灵敏切口 ,切口深度与铝浓度成正比 ,线性范围为 8× 1 0 - 7～6× 1 0 - 5mol/L,检测下限为 6× 1 0 - 7mol/L,相对标准偏差为 4.8% ( n=1 0 ,4× 1 0 - 5mol/L Al)。应用该法测定了天然水中不同形态的铝浓度 ,并同 Driscoll的 MIBK-GF/AAS法进行了比较 ,结果基本一致     

Speciation of aluminium(III) in natural waters using differential pulse voltammetry with a pyrocatechol violet-modified electrode

A differential pulse voltammetric (DPV) procedure is proposed for the speciation of aluminium in natural waters using Pyrocatechol Violet chemically modified electrodes (PCV-CMEs). This novel speciation idea is based on the selective determination of different AlIII forms under two pH conditions. The labile monomeric Al fraction (mainly inorganic Al) is analysed at pH 4.8 (0.20 mol dm(-3) NaOAc-HOAc) and the total monomeric Al fraction is analysed at pH 8.5 (0.20 mol dm(-3) NH3.H2O-NH4Cl). The difference is thought to be caused by the weak competition ability of PCV to sequester AlIII from AlIII-natural organic matter complexes. This sensitive and simple speciation method has been applied successfully to aluminium speciation in natural waters sampled from different regions of China. Five fractions are measured directly or indirectly: (i) labile monomeric Al; (ii) total monomeric Al; (iii) acid reactive Al; (iv) non-labile monomeric Al; and (v) acid soluble Al. The results are in satisfactory agreement with those obtained by Driscoll's 8-hydroxyquinoline extraction-ion exchange method.     

钙镁试剂-示波计时电位法测定天然水和饮用水中铝含量

本文报道钙镁试剂 ( CLG) -示波计时电位法直接测定天然水和饮用水中的铝含量。在 0 .2 mol/L 乙酸 -乙酸铵 ( p H=6.3)缓冲溶液中 ,加入铝后 ,铝 - CL G配合物切口电位为 - 0 .75V,切口深度在 5× 1 0 - 6～ 5× 1 0 - 5mol/L范围内呈线性关系 ,检测下限为 4× 1 0 - 6 mol/L。在 5× 1 0 - 5mol/L时相对标准偏差为 4.7% ( n=1 0 )。应用该法测定了天然水和饮用水中铝含量 ,并同 ICP/AES法所获结果进行了对照 ,结果基本一致     

Speciation analysis of aluminium(III) in natural waters and biological fluids by complexing with various catechols followed by differential pulse voltammetry detection

The biological effects of aluminium have received much attention in recent years. Speciation of Al is of basic relevance as it concerns its reactivity and bioavailability. A differential pulse voltammetry (DPV) procedure is proposed for speciation analysis of Al(III) in natural waters and biological fluids using six catechols (L-dopa, dopamine, epinephrine, norepinephrine, caffeic acid and o-benzenediol) as electroactive ligands. The decrease of the DPV anodic peak current for each catechol ligand is linear with the increase of Al concentration. This speciation analysis idea is based on the measurement of the complexation capacity, namely, different affinities of Al(III) for catechols and organic ligands under two pH conditions. The labile monomeric Al fraction (mainly inorganic aluminium) is determined at pH 4.6, while the total monomeric Al fraction is determined at pH 8.5. The principle for Al(III) speciation analysis by an electrochemical method is discussed. This sensitive and simple fractionation method is successfully applied to the speciation analysis of Al in natural waters and the results agree well with those of Driscoll's method. The speciation analysis of Al in biological fluids is also explored and the results are compared with those obtained by ultrafiltration and dialysis. Compared with other speciation protocols the electrochemical method possesses some remarkable advantages: rapidity, high sensitivity, cheap instrumentation and a simple operation procedure.     

Direct Determination of Labile Monomeric Aluminum in Natural Waters By A.C. Oscillopolarography in the Presence of Rubeanic Acid

ABSTRACT

A simple and sensitive electrochemical method for the direct determination of labile (monomeric inorganic Al speciation) Al concentration in natural waters is developed in this paper. It is based on the use of a.c. oscillopolarography in the presence of rubeanic acid (RA). The optimal experimental conditions are: 1 mol/L NaAc-HAc buffer (pH 5.4) and a RA concentration of 6x10^?4 mol/L. The response is linear over the 2x10^?7 to 2x10^?6 mol/L concentration range. The detection limit is 1x10^?7 mol/L and the relative standard deviation (at the 1.2 x 10^?6 mol/L level) is 5.5%. The method has been applied to the direct determination of labile monomeric Al concentrations in various natural samples. The results were verified by the classic ion exchange method.     

Fractionation of aluminum in natural waters by fluorometry based on the competitive complexation

A novel strategy for the speciation of aluminum has been developed by fluorometry using selective analytical reagents under different pH conditions, which is based on the measurement of the complexation ability of Al for analytical reagents and native organic matters. With Eriochrome Blue Black R, labile monomeric Al and total monomeric Al fractions are determined at pH 4.5 and pH 8.0, respectively. With morin only the labile monomeric Al is determined at pH 4.0, while with 8-hydroxyquinoline the total monomeric Al is determined at pH 5.5. So, acid soluble Al fraction is obtained indirectly. This method is successfully applied to the fractionation of Al in natural waters. The results well agree with those obtained by Driscoll’s 8-hydroxyquinoline/cation-exchange protocol. This fluorometric method possesses some advantages such as high sensitivity, easy manipulation, no separation step and less time-consuming.     

Resonance Rayleigh scattering determination of trace amounts of Al in natural waters and biological samples based on the formation of an Al(III)-morin-surfactant complex

A novel method for the determination of trace amounts of Al(III) based on resonance Rayleigh scattering (RRS) has been developed. In the presence of some surfactants, Al(III) can react with morin and form an Al(III)-morin-surfactant complex, which results in the enhancement of RRS intensity and the appearance of the corresponding RRS spectral characteristics. Their maximum scatter peaks are at 476 nm for the cetyltrimethylammonium bromide (CTAB) system, 489 nm for the cetylpyridinium chloride (CPC) system, 474 nm for the Triton X-100 system, and 473 nm for the Tween-20 system. The enhanced RRS intensity is directly proportional to the concentration of Al(III). The detection limits are in the range of (0.50-1.2)×10⁻⁷ mol l⁻¹ depending on the surfactant. The characteristics of RRS spectra of the complexes, the optimum conditions of these reactions and the influencing factors have been investigated. The method has high selectivity, and was successfully applied to the determination of Al(III) in natural and biological samples. Furthermore, according to different complexation capacity of Al(III)-morin-CTAB system under two pH conditions, speciation analysis of Al(III) in natural waters was explored. The labile monomeric Al fraction (mainly inorganic Al, Al_i) is determined at acidic pH and the total monomeric Al fraction (Al_a) is determined at alkaline pH. The results are in agreement with those obtained by Driscoll’s 8-hydroxyquinoline extraction-ion exchange method.     

Indirect A.C. Oscillopolarographic Determination of Total Monomeric and Acid-Reactive Aluminum in Natural Waters by Using Pyrocatechol Violet

ABSTRACT

Indirect determination of total monomelic and acid-reactive aluminum in natural waters by a.c. oscillopolarography in the presence of pyrocatechol violet (PCV) is presented in this paper. In 0.5 mol 1^?1 NH₄Ac buffer solution (pH 6.4) containing l×lO^?3 mol 1^?1 PCV, PCV yields two incisions on the a.c oscillogram at the potentials of - 0.80 and - 1.20 V, respectively. The incision depth declines when adding aluminum in the solution. The decreases of incision depth (Ep = -1.20 V) has a linear relationship with increasing Al concentrations (4×10^?7 - 4×10^?6 mol 1^?). It is the basis for indirect quantitative analysis. The relative standard deviation is 8.3% for 1×10^?6 mol 1^?1 Al (n = 10) and the detection limit is 2 × 10^?7 mol 1^?1. The proposed method has been applied to determine total and acid-reactive Al in natural waters and the results are compared with Driscoll's 8-HQ-MIBK-GF/AAS and PCV colorimetric methods.     

酸性媒染紫-示波计时电位法测定天然水和饮用水中铝

报道酸性媒染紫（ＳＶＲＳ）－示波计时电位法测定天然水及饮用水中铝。在０．８５ｍｏｌ／Ｌ　ＮＨ３·Ｈ２Ｏ－ＮＨ４Ｃｌ－５×１０－５ｍｏｌ／Ｌ ＳＶＢＳ（ｐＨ８．８）底液中,Ａｌ－ＳＶＲＳ络合物在－１．０５Ｖ电位处产生灵敏切口,切口深度与铝浓度成正比,可用于定量分析。线性范围为１×１０－７～６×１０－６ｍｏｌ／Ｌ． ＲＳＤ为５．５％ （ｎ＝１０,２×１０－７ｍｏｌ／Ｌ）,检测限为５×１０－８ｍｏｌ／Ｌ。本法特点为：在碱性条件下,无需加热,无需通氮除氧,无需预富集,大大减少了分析时间。仪器简单,方法灵敏准确,特别适用于天然水和饮料中Ａｌ的分析。对实际水样进行了分析,与ＩＣＰ／ＡＥＳ法所测结果基本一致。