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1.
《Analytical letters》2012,45(5):1001-1011
Abstract The reaction between titanium(IV) and 3,4-dihydroxybenzoic acid in aqueous media results in an intensely colored complex which is stable for at least 8h. It allows the spectrophotometric determination of titanium in silicate rocks. The proposed method, in pH 4.0–6.0, shows a molar absorptivity of 1.43.104 L.mole?1.cm?1 at 380 nm. Beer's Law is obeyed up to 3.0 μg/mL of titanium(IV). The interference of iron(III) can be eliminated by reduction to iron(II) with hydroxylamine hydrochloride. The method was applied to the determination of titanium in various standard rocks and the results indicated that the accuracy and precision are satisfatory. 相似文献
2.
Neesha Shah M. N. Desai Y. K. Agrawal 《International journal of environmental analytical chemistry》2013,93(1-4):53-60
Abstract A selective and sensitive method for the extraction followed by a spectrophotometric or atomic absorption spectrophotometric determination of titanium(IV) in trace amounts is described. The molar absorptivity of the caffeic acid-Aliquat 336 complex is 5.7 × 104 l mol?1 cm?1 at 380 nm; the yellow coloured complex obeys Beer's law in the range 0.05–1.2 mg/l of titanium in the final extract. The method is applied to the preconcentration, separation and determination of titanium(IV) in steel, industrial effluents and environmental samples. 相似文献
3.
《Analytical letters》2012,45(10):1209-1220
Abstract Two flow injection analysis catalytic-fluorimetric methods for the determination of titanium are suggested, based on the measurement of the peak height and of the peak width, respectively. Both methods allow the determination of titanium at the ng.mL?1 level with good selectivity. A comparison between both method is also established. 相似文献
4.
《Analytical letters》2012,45(4):249-255
Abstract A procedure for the quantitative determination of titanium in silicates is given. Interferences usually associated with silicate parting solutions are studied in order to develop the proper conditions for the titanium sample solution. 相似文献
5.
《Analytical letters》2012,45(13):2551-2568
Abstract Differential Pulse Voltammetric (DPV) methods for the determination of iron (Fe), titanium (Ti), vanadium (V) and chromium (Cr) in a synthetic milling solution of titanium alloy are presented. N-2-hydroxyethyl-ethylene diamine triacetic acid (EDTriA) or ethylene diamine tetraacetic acid (EDTA) was used to replace fluoride in complexing with all the metal ions. EDTriA was found to be a better ligand than EDTA in the determination of Fe, Ti and V. However, the reverse was true for Cr. Ti and Cr, which would interfere in the determination of V, was precipitated from the synthetic solution by adding EDTriA at very high pH. In the Cr determination, Ti and V were the major interfering species. The difficulty caused by Ti was alleviated by precipitating the Ti with EDTA at very high pH. The other difficulty, which was caused by V, was solved by using peak subtraction because of the perfect overlapping of the V and Cr peaks. 相似文献
6.
《Analytical letters》2012,45(5):763-777
A multiwall carbon nanotube titanium dioxide nanoparticle modified carbon paste electrode was used for direct determination of methimazole. The nanoparticles in the carbon paste increased the surface area of the electrode and improved the sensitivity by enhancing the peak current. The electrochemical behavior of methimazole on the modified electrode was investigated. Experimental variables such as pH and electrode composition were optimized. At the optimum pH 7.0 (universal buffer), the modified electrode had a linear dynamic range of 0.5 to 100.0 μmol L? 1 (0.1–11.4 ppm) with a limit of detection of 0.17 μmol L? 1 . The application of the electrode for the determination of methimazole in pharmaceuticals and blood serum was investigated. 相似文献
7.
《Analytical letters》2012,45(11):1697-1717
Abstract The paper briefly reviews the status of titanium as an environmental pollutant and presents a new method suitable for the microdetermination of the metals in plants, animal tissues and waters. The method is based on extractive separation of titanium as its chelate with N-p-methoxyphenyl -2-furylacrylohydroxamic acid (MFHA) in chloroform or isoamyl alcohol and subsequent spectrophotometric or atomic absorption spectrometric determination. MFHA was chosen from nine new hydroxamic acids as detailed in the paper. The overall sensitivity of the spectrophotometric method with chloroform as extracting solvent i s better than 1 ppb (0.001 ppm). For atomic absorption spectrometric determination isoamyl alcohol is used as extracting solvent and a sensitivity of 0.2 ppm, which is ten times better than attained earlier, is achieved. There was excellent agreement between the results obtained by the two different instrumental methods. 相似文献
8.
《Analytical letters》2012,45(5):963-972
Abstract In the present communication a simple and rapid spectrophotometric method for the determination of titanium is described. The method is based on the reaction of Ti(IV) with a newly synthesized reagent, 6-(4-nitrophenylazo)-3,4,5-trihydroxy benzoic acid (NATHB), in ethanol medium at pH 3.2 to 4.2. The complex exhibits an absorption maximum at 495 nm and Beer's law is valid over the range of 0.04 – 1.00 μg.ml?1 Ti. The molar absorptivity is 3.48 × 104 dm3.mole?1. cm?1. Most of the foreign metal ions and anions do not produce any colorations with NATHB at selected conditions. Based on these results, a simple and direct spectrophotometric method with high selectivity and sensitivity was proposed. The method has been successfully applied for the determination of titanium in 5 soil and 3 standard geochemical samples. 相似文献
9.
《Analytical letters》2012,45(12):2649-2660
Abstract The reaction between cyclohexan-1,2-dione bissalicyloylhydrazone and titanium(IV) has been studied spectrophotometrically. An orange complex (λ = 470 nm, ? = 1.49 × 104 1.mol?1.cm?1) is quickly formed at pH 1–2.5 in a 3+2 V/V ethanol/water medium. Interferences (more than 65 species) have been investigated. In presence of some masking agents most of metal ions do not interfere. The orange complex has been satisfactorily used for the determination of titanium in amphibolites, granites, suspended matter, Portland cement, bauxite, cast iron and duraluminium alloy. The results are compared with those obtained using AAS and ICP methods. 相似文献
10.
《Analytical letters》2012,45(12):2384-2390
Abstract A novel spectrophotometric method for the determination of titanium(IV) by using a new reagent, water extract of slippery elm leaf is developed. In 0.05 M hydrochloric acid, titanium(IV) reacts with this reagent to form a yellow product. The formed product shows maximum absorbance at 415 nm with a molar absorptivity value of 0.68×104 l mol–1 cm–1 and the method was linear in the 0.2–6 µg ml?1 concentration range. The detection limit value was found to be 0.0131 µg ml?1. The proposed method was simple, low cost, selective, and sensitive. It was applied to the analytic samples with satisfactory results. 相似文献
11.
The possibility of application of the radioactive source excited X-ray fluorescence analysis for titanium and iron determination
in kaolins to the routine test of the refinement process has been studied. The iron content can be determined with a simple
counting system using a single-channel pulse height analyser, argon filled proportional counter and109Cd source of 3 mCi for the excitation of K Fe rays. The samples were analysed both as pellets and powders. The iron content
ranged from 0.2–2.5% and titanium from 0.1–0.64%. For simultaneous determination of titanium and iron a Si(Li) spectrometer
has been used. The238Pu source has been used for K Fe and K Ti excitation. It is the most convenient source for simultaneous determination of titanium
and iron.55Fe is the most efficient source for the determination of titanium alone. The best values of precision and determination limit
have been achieved for iron with238Pu and for titanium with55Fe. 相似文献
12.
《Analytical letters》2012,45(1):31-41
Abstract Thiothenoyltrifluoracetone (STTA) was used for the simultaneous extraction and direct spectrophotometric determination of bismuth at microgram concentration. About 98.5 μg of bismuth was extracted as the orange-red colored complex with 10 ml of 0.001 M STTA in carbontetrachloride. The extraction was quantitative at pH 6. The system conformed to Beer's Law in the concentration range of 2.5 to 30 μg/ml of bismuth at 460 nm. The method is both sensitive and selective. The molar absorptivity was 5.6 × 103 and sensitivity was 0.037 μg/cm2. The method is selective as it is possible to accomplish extraction and colorimetrically determination of bismuth in the presence of 1:50 of several ions. Only ions such as cadmium, tin, iron, titanium and nickel interfere seriously. The overall process of extraction and determination takes hardly 30 minutes. The method is reproducible. 相似文献
13.
A highly selective and sensitive catalytic method for the determination of trace amounts of titanium(IV) was developed. The method is based on the catalytic effect of titanium(IV) on the methylene blue‐ascorbic acid redox reaction. The reaction was followed spectrophotometrically by measuring the change in absorbance of methylene blue at 665 nm, 5 minutes after the initiation of the reaction. In this study experimental parameters were optimized and the effect of the presence of various cations and some anions on the determination of titanium(IV) was examined. The calibration graph was linear in the range of 3‐25 ng mL?1 of titanium(IV). The relative standard deviation for the determination of 10 and 20 ng mL?1 of titanium(IV) were 2.64% and 1.51%, respectively (n = 8). The detection limit calculated from three times of standard deviation of blank 3Sb was 0.6 ng mL?1. The method was successfully applied to the determination of titanium(IV) in tap water and ore samples. 相似文献
14.
《Analytical letters》2012,45(14):3025-3035
ABSTRACT The paper represents a continued study of selected heavy metals concentration in the Arge? River, the fifth river in length from Romania. For the determination of metal ion concentration in Arge? river was used Atomic Absorption Spectrometry for sodium, potassium and magnesium; Direct Coupled Plasma Atomic Emission Spectrometry for calcium; Inductively Coupled Plasma Atomic Emission Spectrometry for copper, cadmium, zinc, aluminium, lead, titanium, zirconium, chromium, molybdenum, manganese, iron and nickel. Copper, cadmium, zinc and lead concentration were determined by ICP–AES and ASV and results were reliable. By comparison of the results a good agreement between these two techniques is observed. 相似文献
15.
Mohammad Muneer Mohd Saquib Mohd Qamar Detlef Bahnemann 《Research on Chemical Intermediates》2010,36(2):121-125
The photocatalyzed oxidation of indole (1) in an aqueous suspension of titanium dioxide has been investigated and an attempt has been made to identify the products
formed during the photooxidation process by gas chromatographic–mass spectrometric (GC–MS) analysis. Photolysis of an aqueous
solution of indole (1) in the presence of titanium dioxide and oxygen led to the formation of 2,3-dihydroindole-2-one (6) and 1H-indole-2,3-dione (7). A probable pathway for the formation of these products has been proposed. 相似文献
16.
《Analytical letters》2012,45(7):1327-1338
ABSTRACT This article presents a method for determination of titanium in quartz and silica glass samples based on adsorptive stripping voltammetry (AdSV) with mandelic acid. Hanging mercury drop electrode as a working electrode was used. The optimized conditions include: pH 3.3, accumulation potential –0.15 V, accumulation time 90 s, scan rate 10 mV/s, pulse amplitude 25 mV. In case of 5 min accumulation time the obtained detection limit was 6.5×10-9 mol/L Ti. ET-AAS was applied as a reference method to AdSV measurements. The procedure for decomposition of quartz and silica glass samples applying small amount of acids is described. 相似文献
17.
Adsorptive stripping voltammetric (AdSV) methods are presented for the determination of titanium and iron in quartz and silica glass samples obtained after pressure decomposition. Mandelic acid and catechol were used as complexing agents for titanium and iron, respectively. The method for titanium determination is based on the catalytic effect of chlorate ions. An insoluble residue remaining after decomposition of quartz and silica glass samples in HF+H2SO4 mixture was checked by energy-dispersive X-ray analyses. ET-AAS was applied as a reference method to AdSV measurements. 相似文献
18.
Kamal I. Aly Nayef S Al-Muaikel Mona A. Abdel-Rahman Amal H. Tolba 《Liquid crystals》2013,40(11):1734-1746
ABSTRACTPolymer nanocomposites are already a part of many important worldwide businesses. Among many nanocomposite precursors, titanium dioxide (TiO2) nanopowder is increasingly being investigated due to its special properties. In this work, the feasibility of synthesising a new series of materials, copoly(arylidene-ether)/titanium dioxide nanocomposites, using in-situ copolymerisation technique has been investigated. This can be performed by the interaction of both cyclohexanone and 4-tert-butylcyclohexanone monomers with 4,4′-diformyl-2,2′-dimethoxy-α,ω-diphenoxyalkanes Ia–e, respectively, using different additions of titanium dioxide-P25. The structure of the prepared nanocomposites IIa–e/TiO2 (0.2–3.0%) was confirmed by elemental analysis (energy dispersive X-ray spectroscopy) and spectral data (Fourier transform-infrared [FT-IR]). FT-IR verified the dispersion of nanofillers in the copolymer. Then, the characterisation and applications of these nanocomposites are extensively discussed depending on the investigation of how the addition of titanium dioxide nanoparticles affected on their properties using various techniques, such as X-ray diffraction, SEM, transmission electron microscopy, Water Contact Angle (WCA), thermogravimetric analysis, differential thermogravimetric, differential thermal analysis (DTA), polarising optical microscope and UV–vis absorption spectroscopy. The nanoparticles affected on the copolymer thermal behaviour in different ways (discrepancy results) depending on how these nanoparticles are dispersed in the copolymer matrix. UV–vis absorption spectra displayed a decrease in the optical band gap of some nanocomposites, which resulted from the addition of titanium dioxide to these copolymers, and this can improve the efficiency of them as organic emitting materials. 相似文献
19.
20.
By the application of thin-layer chromatography on silica gel H and the solvent system consisting of 6 M HCl:acetylacetone: 9 M H2SO4 (60:2:1, v/v/v), zirconium and titanium have been quantitatively separated from each other, as well as from numerous other interfering ions. The efficiency of the chromatographic separation was evaluated by semiquantitative determination of zirconium and titanium by visual colorimetry of spots in situ, as well as by spectrophotometric determination of zirconium with rutin after its elution from silica gel H thin-layer. 相似文献