Extractive Spectrqphotometric Determination of Vanadium Liith o-Aminobenzo-Hydroxamic Acid

Abstract

A new spectrophotometric method for vanadium determination is proposed. The method is based on the extraction in Adogen-toluene solution of the complex formed between V(V) and o-Aminobenzohydraxámic acid

The method allows determination of 50 to 110 μg of V(V). The error and the apparent molar absorptivity are 1.2% and 5.2 ± 10³ l.mol^?1. cm^?1 respectively. The interferences caused by foreign ions have been established. The method is applied with success to determination of vanadium in petroleum crudes.     

催化动力学褪色光度法测定痕量钒

研究了在H3PO4介质中,钒(V)对KBrO3氧化偶氮氯磷mA褪色反应的催化作用及柠檬酸的活化作用,建立了测定钒的新方法。实验发现,无柠檬酸时体系为准零级反应,表观活化能为54.3kJ/mol。在柠檬酸存在下则为准一级反应,表观活化能为30.9kJ/mol,钒的量在0~5.0×10-8g/mL范围内与log(A0/A)呈线性,检出限为5.6×10-11g/mL。在NH4F及尿素存在下,大多数常见离子无干扰。可用于钢样中微量钒的直接测定。     

Spectrophotomhtric Determination of Vanadium with Salicylic Acid in Formic Acid Medium

Abstract

A method is described for the spectrophotometric determination of vanadium by measuring its colored complex with salicylic acid in formic acid medium. Lambert-Beer's law is followed in the range of 2.0 - 32.0 μg V/ml of the final solution. Thirty-six ions were tested and did not interfore, at the established conditions.     

Sensitive Spectrophotometric Determination of Vanadium in Environmental Samples at PPB Levels

Abstract

A new, sensitive and selective method for separation, and extraction - spectrophotometric determination of V (V) with pyrogallol {Ar (OH)₃} and hydroxyamidines (HOA) is described. The molar absorptivities of the colored species with six substituted HOA lie in the range of (0.52–1.5)x 10⁶ L mole^?1 cm^?1 at λ_max 430–440 nm. Of these, the simplest compound, N-hydroxy-N, N- diphenylbenz-amidine (HDPBA) gives the most sensitive color reaction and hence, it is used for detailed studies. No interference of almost all diverse ions tested is noticed. The method offers the determination of vanadium in different environmental samples.     

流动注射催化光度法测定化探样品中痕量钒

利用痕量钒对铍试剂Ⅲ-抗坏血酸体系的催化作用，建立了一个流动注射-分光光度法测定化探样品中痕量钒的方法。该方法具有灵敏度高，分析速度快的特点。选择反应温度为90℃时，反应速度加快，测量时间由普通光度法1h减少到约1min，分析速度为60样次／h。方法的检测限为7μg／L，对于含钒0．4mg／L的试样,RSD为0．6％（n＝30），用于化探样品，分析结果满意。     

测定化探样品中痕量钒的流动注射光泽精化学发光法

用配有Jones还原器的流动注射系统,研究了光泽精与钒(Ⅱ)的化学发光反应,并建立了钒的流动注射化学发光分析法。该法线性范围为1×10-6～1×10-2 g/L ,检出限为3×10-7 g/L,相对标准偏差为2.0 %(1×10-4 g/L,n=11),相关系数在0.9988以上。已用于化探样品中痕量钒的测定,结果令人满意。     

Extraction Spectrophotometric Determination of Vanadium in Industrial Waste Water

A new and simple extraction spectrophotometric method for the determination of vanadium(V) with KIO₄, N‐phenylbenzohydroxamic acid (PBHA) and crystal violet (CV), in industrial waste water samples is described. It is based on the extraction of mixed‐ligand complex V(V)‐IO₄^? ‐PBHA‐CV⁺ into chloroform solution over 2‐7 MHC1. The molar absorptivity of the complex is (7.20) × 10³1 mol^?1 cm^?1 at λ_max 535 nm. The detection limit of the method is 44 μg 1^?1 V. The linearity of the calibration curve is followed up to 6 μgmL^?1 in the organic solution with slope, intercept and correlation coefficient of 1.34 × 10^?1, 6.7 × 10^?3 and +0.99, respectively. This method enhances the sensitivity of the conventional PBHA method for the determination of vanadium, and is free from interferences of other metal ions commonly associated with vanadium. The method has been successfully tested for the determination of V in the industrial waste water samples.     

用若丹明B光度法测定石煤渣中微量钒

研究了痕量V(Ⅴ)催化KBrO3 氧化还原型若丹明B(RRhB)的显色反应 ,建立了光度法测定石煤渣中痕量V(Ⅴ)的新方法。结果表明在抗坏血酸存在下具有高灵敏的显色反应 ,摩尔吸光系数为3.8×105 L·mol-1·cm-1,显色程度与V(Ⅴ)量在0～100μg/L范围内符合比耳定律。该法用于测定石煤渣中的微量V时 ,结果令人满意。     

同时测定合成样中铜钴镍钒含量的分光光度法--主成分回归法和偏最小二乘法比较

研究了主成分回归和偏最小二乘方法在多组分分光光度法分析中的应用,以５－Ｂｒ－ＰＡＤＡＰ（２〔５－溴－２－吡啶）－偶氮〕５－二乙氨基苯酚）为显色剂,ＯＰ（聚乙二醇辛基苯基醚）作为增溶增稳剂,在ｐＨ＝３．６的条件下,用主成分回归及偏最小二乘分光光度法同时测定了合成样中的铜、钴、镍、钒４组分含量,测定相对误差在－６．００％～４．００％之间。实验证明,对于加和性不好的体系偏最小二乘分光光度法要优于主成分回     

容量法测定氧化钒中的各种价态钒

用NaOH溶液处理样品，分离V（V）然后以Fe(Ⅱ）滴定测定之。定量加入过量的V（V）到上述残渣中并用H2SO4溶解，用Fe(Ⅱ）滴定，计算出V（Ⅱ），V（Ⅲ）的含量。V（Ⅳ）的测定是通过从总钒量中扣除V（Ⅱ）、V（Ⅲ）、V（Ⅴ）的含量得到。V（Ⅱ）、V（Ⅲ）和V（Ⅴ）的回收率均大于96％，其8次测定结果的相对标准偏差分别为：9．8％、0．4％、1．2％；本法快速、简便，在实际应用中效果良好。     

含钒碳质页岩中钒的物相分析

将含钒碳质页岩经物相分离后 ,在浓度为 0 .75mol/ L H3 PO4介质中及 H2 O2 存在下 ,以 Na F、Cy DTA为掩蔽剂 ,5- Br- PADAP为显色剂 ,分别测定矿物各相中钒的含量。方法检出限为 2 .6× 1 0 -8mol/ L,RSD为4 .9% ( n=5)     

六极杆碰撞反应池-等离子体质谱测定生物样品中痕量铬和钒

采用带六极杆碰撞反应池的电感耦合等离子体质谱直接测定了生物样品中痕量铬和钒。在碰撞反应池中引入He/NH3(93∶7)混合气,有效地消除了分子离子(ArC 、NCl 、Cl O 、Cl OH 等)对超痕量铬、钒测定的干扰,降低了方法的检出限。比较了干法灰化和湿法消解两种样品处理方法,两种消解方式获得的结果基本一致。方法的检出限(3σ):钒为0.005 0μg.g-1,铬为0.001 8μg.g-1。相对标准偏差:钒为3.25%~14.08%;铬为4.20%~8.24%。经国家一级生物标准物质验证,测定值与标准值吻合。     

Extract-Photometric Determination of Vanadium with Isophthaldihydroxamic Acid

Abstract

The spectrophotometric study of violet complex isophthaldihydroxamic acid-vanadium extracted into solution of trioctylmethylammonium chloride in ethylacetate was made (λ_max = 380 nm, ? = 7500 l.mol^?1.cm^?1; λ_max = 510 nm, ? = 5510 l.mol^?1 .cm^?1; stoichiometries, 1:1 and 1:2, V:reagent). A new method for the extract-spectrophotometric determination of V(V) in the range 14–80 μg of vanadium is proposed.     

电感耦合等离子体原子发射光谱法测定五氧化二钒中19种杂质元素

采用盐酸消解五氧化二钒样品及其中所含可溶性杂质,再以无水碳酸钾与硼酸高温熔融不可溶性杂质,然后以盐酸溶解熔块,合并溶液后以用电感耦合等离子体原子发射光谱法测定杂质元素铌、锆、钛、钨、硅、铝、钼、钴、铬、镍、铜、铅、镉、砷、磷、铁、锰、钙和镁的含量。试验了基体元素和共存元素对测定的干扰,优化各元素的分析谱线,运用同步背景校正消除基体影响。19种元素的检出限在10～225μg.L-1之间,背景等效浓度在5～150μg.L-1之间。方法用于分析五氧化二钒样品,测定结果与其它化学分析方法测定值一致;分析五氧化二钒标准样品(GSBH 42015-96)的测定值与标准值相一致。     

钒(Ⅴ)-硫氰酸盐-碱性三芳基甲烷染料的显色反应研究

研究了在表面活性剂存在下,钒(V)与硫氰酸盐和结晶紫、孔雀绿、灿烂绿、甲基紫及维多利亚蓝4R等碱性三芳基甲烷染料形成离子缔合物的显色反应.讨论了钒(V)-硫氰酸盐-结晶紫-阿拉伯树胶体系的反应条件和分析特性。摩尔吸光系数为2.55×10⁵L·mol^-1·cm^-1.此法可用于铝合金中微量钒的测定。     

Recent Developments in Spectrophotometric Methods for Determination of Vanadium

Owing to the toxic and essential nature of vanadium in biological systems, there has been considerable interest in the determination of its content in different kinds of samples. Among several analytical techniques for the determination of vanadium, spectrophotometric methods are very popular due to their simplicity and low-cost instrumentation. Various attempts have been made to modify these methods in order to improve their sensitivity and selectivity. This review shows recent developments in the spectrophotometric determination of vanadium and highlights those which can be used for speciation analysis of this element.     

钒渣中二氧化钛的容量法测定

本文报道钒渣中测定二氧化钛的硫酸高铈容量法，在盐酸－硫酸混酸介质中，控制磷酸浓度大于３．５ｍｏｌ／Ｌ，在用铝片还原Ｔｉ（Ⅳ）时可以消除大量钒的干扰，方法用于实际试样分析，结果较好。     

Catalytic Determination of Vanadium in Blood and Urine

Abstract

Trace amounts of vanadium catalyze the oxidation of phenylhydrazine-p-sulfonic acid by sodium chlorate. The diazonium salt produced is coupled with 1-naphthylamine to form an azodyestuff whose absorbance is read at 530 nm. Interferences ate eliminated by separating the vanadium by solvent extraction. Physiological concentrations of vanadium are determined in 10 ml. of ashed human blood or plasma and 25 ml. of ashed human urine. Recovery studies are reported along with results for the analysis of blood and urine samples.