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在pH 9.5的NH3-NH4C l缓冲溶液中,汞(Ⅱ)与双硫腙可形成能稳定存在的螯合物微粒,显示出共振散射效应。该微粒体系的最强共振散射峰在560 nm处,汞(Ⅱ)的质量浓度在0.028~6.140μg/mL范围内,共振散射与△I之间存在良好的线性关系,回归方程为△I=76.786ρ+2.7,相关系数为0.999 8,检出限0.012μg/mL Hg。利用共振散射测量水样中微量汞(Ⅱ),方法简单、灵敏度高、结果满意。 相似文献
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T. Schnherr R. Linder U. Rosellen V. Schmid 《International journal of quantum chemistry》2002,86(1):90-99
The molecular and electronic structure of the three tautomeric forms of dithizone has been calculated by using semiempirical, density functional theory (DFT), and ab initio methods. Comparison of ground‐state energies shows the symmetric form most stabilized, but there is only a small barrier (<3 kcal/mol) for the hydrogen transfer from N? H toward H? S (enol form). For understanding the origin of the optical transitions intermolecular interactions have to be taken into account. By using the supermolecule method, the absorption band pattern can be rationalized already on the level of the PM3 model. The nuclear magnetic resonance (NMR) solution spectrum is interpreted in terms of an equilibrium between the symmetric and the enol forms of dithizone. The appearance of strong EPR signals only for the solid state reflects a considerable lowering of the triplet state (symmetric form). Experimental features are discussed in view of calculated energies (stabilization), chemical shifts (NMR), and SOMO orbitals (EPR). © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 相似文献
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Elementveruninigungen auch im Spurenbereich (ppm, ppb) becinflussen die Qualität von Halbleiterselen. Bei der Bestimmung interssierender Elemente (Ag, As, Au, Cd, Ga, Sb, Tl) mittles NAA ist mich der Neutronenbestrahlung im Kernreaktor wegen der Störung dutch die entstehende hohe Matrixaktiviät, der Anwesenheit reiner Betastrahler oder infolge Linienüberlagerung im Gammaspektrum im allgemeinen Keine instrumente NAA möglich. Daher müssen nache Zugabe inaktiver Träger und der Matrixabtrennung die interessierenden E-emente durch konventionel-e chemisch-analytische Trennverfahren (Extraktion, Fällung, Ionenaustausch) isoliert warden. 相似文献
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Juthathip Wongthanyakram 《Analytical letters》2019,52(3):550-561
An iPod-based digital image colorimeter was developed for the determination of lead(II) in cassava. The method is based on the color values of a lead(II) solution following its reaction with dithizone. Lead(II) from cassava was extracted using an ultraviolet-digestion unit followed by the color-forming reaction and image capture using the ColorConc application operated on an iPod touch. The concentration was predicted by comparing the color values with those collected in a database. The time needed for complete digestion was 30?min. The determined concentrations of lead(II) were from 0.10 to 1.00?µg mL?1. The limits of detection and quantitation were 0.0120 and 0.0399?µg mL?1, respectively. The recovery values were 105?±?7.07% and 109?±?6.61% at 0.2?µg mL?1 and 0.4?µg mL?1 lead(II) (n?=?5). The reported method was demonstrated to be simple, accurate, rapid, precise, and low cost. 相似文献
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Trevor T. Chiweshe Marilé Landman Jeanet Conradie 《Journal of Coordination Chemistry》2016,69(5):788-800
In view of the important role of dithizone in trace metal analyses, new structural aspects and approaches used to probe metal complexes of dithizone are of interest. Three X-ray diffraction structures are reported, dichloridobis(dithizonato)tin(IV), dichlorido(dithizonato)antimony(III), and bis(dithizonato)copper(II). During synthesis of the tin complex, auto-oxidation of SnIICl2 to SnIV occurred without chloride liberation. The SbIII complex revealed a unique distorted see-saw geometry which is, as for the other complexes, predicted by DFT molecular orbital calculations. The computed products of the lowest energy reactions are in agreement with experimentally obtained reaction products, which, together with molecular orbital renderings serve as a tool toward prediction of modes of coordination in these complexes. The S–M–N bond angle in the five-membered coordination ring shows a linear relationship with the corresponding metal ionic radii. 相似文献
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本文研究了汞(Ⅰ)-双硫腙-β-环糊精在1.2mol/L氢氧化钠溶液介质中的显色反应,并以双波长分光光度法测定痕量汞。配合物的表观摩尔吸光系数为1.16×105L·mol·cm-1,桑德尔灵敏度为1.74×10-3μg/cm?2 。0~30μg/mL的汞服从比尔定律。方法用于水样,银耳,矿样中汞的测定,结果 相似文献
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萃取催化动力学分析法测定痕量钯 总被引:10,自引:2,他引:10
本文研究了在pH3.O的缓冲溶液中,利用邻菲罗嘛活化Pd(Ⅱ)催化水中溶解氧氧化二苯硫腙褪色的指示反应,建立了测定痕量钯的萃取催化动力学分析方法。方法的灵敏度为3.3×10 ̄(-9)g/mL,线性范围为7.5×10 ̄(-9)~4.0×10 ̄(-7)G/mL。用于钯催化剂中钯的测定,获得了满意的结果。 相似文献
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双硫腙——CPC与铜显色反应的研究和应用余协瑜罗姿容吴德岚(重庆钢铁高等专科学校应用化学系重庆630050)关键词分光光度法铜双硫腙氯化十六烷基吡啶中图分类号O657.32双硫腙应用于铜的测定早有报导[1],但需用CCl4萃取。本文研究了CPC对铜(... 相似文献
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Lata Mathew Talasila Prasada Rao Chonatumatom S. P. Iyer Alathur D. Damodaran 《Mikrochimica acta》1995,118(3-4):249-256
A first-order derivative spectrophotometric method has been developed for the simultaneous determination of copper, mercury and lead at g/L levels using dithizone as reagent. The procedure involves the simultaneous extraction of these elements by dithizone in chloroform from weakly alkaline solutions. Linear calibration curves were obtained in the ranges 0.5–10 (Cu), 1–10 (Hg) and 1–10 (Pb) g present in 40 ml of aqueous phase with detection limits of 5 g/L (Cu) and 20 g/L (Hg and Pb). The R.S.D.s for 100 g/L of copper, mercury and lead were 2.5, 2.6 and 3.1% respectively, for 5 determinations. The method is applicable for the determination of copper and lead in marine sediment samples with good precision and accuracy. 相似文献