Flow-injection spectrophotometric determination of fluoride by using the zirconium/alizarin red S complex

A spectrophotometric flow-injection procedure is described for fluoride in aqueous samples. The method is based on the decrease in absorbance of the zirconium/alizarin red S complex at 520 nm; linear response is obtained for the range 0.1–10 mg l^?1 fluoride at a sampling rate of 100 h^?1. Aluminum(III), iron(III) and phosphate interfere.     

Spectrophotometric study of a ternary zirconium/fluoride/alizarin complex with application to the determination of zirconium

A ternary zirconium/fluoride/alizarin complex is extracted into methyl isobutyl ketone. The apparent molar absorptivity at 556 nm is 1.52 × 10⁵ 1 mol^?1 cm^?1. The r.s.d. is 1.3% for 10 μg Zr (n = 12). There are several interferences, some of which can be masked with EDTA.     

Spectrophotometric determination of aluminum with bromopyrogallol red in the presence of surfactants

Spectrophotometric methods are described for the determination of microgram amounts of aluminum based on the formation of a ternary complex between the metal, bromopyrogallol red, and cetyltrimethylammonium bromide or nonylphenol tetradecaethylene glycol ether. The complexes have absorbance maxima at 627 and 612 nm, respectively, with molar absorptivities of 5.0 × 10⁴ and 2.2 × 10⁴ liter mol^?1 cm^?1. Numerous metals interfere. Aluminum can be easily separated by extraction of interfering ions with cupferron.     

Spectrophotometric determination of zirconium with 5,7-dibromo-8-hydroxyquinoline in presence of thiocyanate

The characteristics of the ternary complex formed between zirconium(IV) and 5,7-dibromo-8-hydroxyquinoline in presence of thiocyanate have been studied with an analytical point of view. The resulting colored species is extractable into chloroform with absorption maximum at 416 nm, which leads to the determination of the trace amounts of the metal ion. The method obeys Beer’s law in the range 0.2–9.0 μg Zr/mL having molar absorbitivity and Sandell’s sensitivity values of 1.05 × 10⁴ L/mol cm and 0.0087 μg Zr/cm², respectively. The ratio of zirconium(IV), 5,7-dibromo-8-hydroxyquinoline and thiocyanate in the extracted species is found to be 1: 2: 2. A large number of foreign ions do not interfere in the proposed method. The applicability of the procedure is tested by carrying out satisfactorily the analysis of a wide variety of samples.     

荷移反应分光光度法测定苯巴比妥钠

采用分光光度法研究了电子给体苯巴比妥钠与π电子受体茜素红的荷移反应,建立了荷移分光光度法测定苯巴比妥钠的方法。在水溶液中,苯巴比妥钠与茜素红荷移络合物的最大吸收波长为530 nm,该络合物的组成为1∶1,表观摩尔吸光系数ε为4.43×103L.mol-1.cm-1,稳定常数为2.30×105。药物质量浓度在5~40 mg/L范围内符合比尔定律,相关系数为0.9996。当苯巴比妥钠浓度为20 mg/L时,10次测定结果的相对标准偏差为1.3%。测定了针剂中的苯巴比妥钠,加标回收率在98.9%~105%之间。     

Spectrophotometric determination of zirconium with pyridoxal salicyloylhydrazone

The synthesis, characteristics and analytical applications of pyridoxal salicyloylhydrazone are described. The reaction between zirconium(IV) and this reagent was studied spectrophotometrically. A yellow 1:2 Zr:L complex (? = 2.4 × 10⁴ l mol^-1 cm^-1 at 395 nm) is formed from pH 3.5 to 5 M hydrochloric acid in an aqueous solution containing 2% dimethylformamide and 28% ethanol. The method is highly selective and is applied to the determination of zirconium in a steel and a nickel—chromium alloy.     

Spectrophotometric determination of zirconium in steels with xylenol orange

Zirconium (0.005–0.25%) is determined after acid dissolution of the steel, and fusion of insoluble matter with sodium carbonate and sodium hydrogensulphate. Niobium and other interfering ions are removed by mercury cathode electrolysis. Residual small amounts of iron(III) are masked with ascorbic acid.     

Spectrophotometric determination of chromium(III) with bromopyrogallol red in the presence of Septonex

A new spectrophotometric method has been developed for the determination of chromium(III) with bromopyrogallol red in the presence of the cationic tenside, carbethoxypentadecyltrimethylammonium bromide (Septonex) at pH 4.0 and within a concentration range from 0.1 to 1.4 μg Cr(III) ml⁻¹.     

Spectrophotometric determination of zirconium using robinetin

Summary The complex formation between zirconium and robinetin has been spectrophotometrically investigated and made use of in the determination of zirconium. The complex has been found to contain zirconium and the flavonol in the molar ratio of 12. It obeys Beer's law up to 3.0 ppm of Zr and its stability constant has been calculated to be l.5×10⁹. The reaction is quite sensitive and selective at high concentrations of hydrochloric acid (sensitivity 0.0045 g/cm²).

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Zusammenfassung Zur spektrophotometrischen Bestimmung von Zirkonium wird als Reagens Robinetin empfohlen, das mit Zr einen Komplex im Verhältnis 12 (ZrRobinetin) bildet. Die Stabilitätskonstante wurde zu 1,5 · 10⁹ bestimmt. Das Beersche Gesetz wird bis zu 3,0 ppm Zr befolgt. In stark Salzsauren Lösungen ist die Reaktion empfindlich und selektiv (Empfindlichkeit: 0,0045 g Zr/cm²).

     

茜素红荷移光度法测定阿魏酸哌嗪

研究了茜素红与阿魏酸哌嗪的显色反应,建立了阿魏酸哌嗪含量测定的分光光度法.在水溶剂中阿魏酸哌嗪与茜素红发生荷移反应生成紫红色的复合物,其最大吸收波长为524nm,表观摩尔吸光系数为1.86×103 L·mol-1·cm-1.阿魏酸哌嗪的浓度在1.60⁴8.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%48.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%¹00.9%之间.     

Spectrophotometric determination of scandium with bromopyrogallol red

A highly sensitive spectrophotometnc method for scandium with Bromopyrogallolo Red is described;) mierogram amounts of scandium can be determined by measurement 'at 610 mmu and pH 6-1. The molar-absorptivity is 2.4 x 10(4) at 610 mmu. Formation of a 1:1 complex of scandium with Bromopyrogallol Red is confirmed, Common cations interfere, but can be separated completely by three successive ioń-exchange (Steps, so the method can be applied to the determmation of traces of scandium in silicate rocks. Results are quoted for scandiumn in several types of igneous rocks.     

Spectrophotometric determination of molybdenum(VI) with Bromopyrogallol red in the presence of Triton X-114

The complexation of molybdenum(VI) with Bromopyrogallol Red in the presence of the nonionic surfactant Triton X-114 is studied spectrophotometrically. A mixed-ligand complex is formed with the component ratio 1: 1: 1 and a stability constant of logβ = 8.2. The effect of pH, time, temperature, and component concentrations on the formation of the mixed-ligand complex is studied. A highly selective procedure for the spectrophotometric determination of trace molybdenum(VI) in drinking water in the presence of tungsten has been developed.     

Spectrophotometric determination of fluoride with lanthanum/alizarin complexone by flow injection analysis

Lanthanum/alizarin complexone (1:1) in 70% acetone is used in conjunction with a 500-cm reaction coil at 60°C to determine 0.03–1.2 mg l^?1 fluoride at 24 samples per h. The method is applied to tap-water samples.     

Ionic association with anions of alizarin red S in aqueous solutions with surfactants

The formation of associates of single (H₂An⁻) or doubly charged anions (HAn²⁻) of alizarin red S with cations (Ct⁺) of cyanine dye pinacyanol in aqueous solution is considered. Thermodynamic values of equilibrium association constants were determined according to spectrophotometric data. Values of enthalpy of formation for the associates of the composition Ct⁺ · H₂An⁻ and (Ct⁺)₂ · HAn²⁻ were calculated with the help of semi-empirical methods. It was determined that the addition of cationic or anionic surfactant results in the destruction of associates.     

茜素红 S与蛋白质的反应机理研究

应用UV光谱法研究在pH4.35的缓冲溶液中, 茜素红 S(ARS)与牛血清蛋白(BSA)间的相互结合反应。测定了平均结合数n=8, 分配结合常数K~c=1.5×10^5。研究了小分子探针与蛋白质的反应机理, 相互间的结合部位及结合力。该复合物结合前后的等吸收波长红移28nm, 这是目前此类结合反应研究中, 其分子间结合力较大的一例。进一步研究了ARS与多种蛋白质的结合反应, 以及离子强度对该体系的影响。提出了合适的反应模型。     

Spectrophotometric determination of molybdenum with Alizarin Red S in the presence of poly(sulfonylpiperidinylmethylene hydroxide)

The present work describes a selective and rapid method for the determination of molybdenum with Alizarin Red S (ARS) in the presence of a water soluble polymer, poly(sulfonylpiperidinylmethylene hydroxide) (PSPMH). The ARS modified by PSPMH reacts with molybdenum(VI) in the solutions of pH 3.4-4.0 to produce a red complex. The composition of the complex is 1:4:1 mol ratio of Mo(VI): ARS:PSPMH. The complex obeys Beer's law from 0.05 to 5.50 μg ml⁻¹ with an optimum range. The molar absorptivity is 2.1×10⁴ l mol⁻¹ cm⁻¹ at 500 nm. The interference effects of the foreign cations have been examined and it has been determined that only Cu(II), Al(III) and Fe(III) have to be masked by EDTA and tungsten can be tolerated till 4-fold of molybdenum in case of masking by citrate. The method has been applied to the determination of geological samples without solvent extraction or separation steps.     

Spectrophotometric determination of samarium(III) with chrome azurol S in the presence of cetylpyridinium chloride

A sensitive, simple method for the determination of trace amounts of samarium by spectrophotometry is described based on the formation of the samarium-chrome azurol S (CAS) complex in micellar medium. The molar absorptivities of the complexes at pH 7.5 at 505 nm were 3.6x10(4) and 1.4x10(5) l mol(-1) cm(-1) for water media and cetylpyridinium chloride (CPC), respectively. Beer's law is obeyed from 0.05-2 mg l(-1) of samarium at 505 nm as Sm-CAS-CPC complex. Optimal conditions such as reagent amounts, and pH for the samarium determination were reported. The effects of foreign ions were also investigated. The proposed method was successfully applied to the determination of samarium contents in synthetic samples.     

Spectrophotometric determination of zirconium with 9-methyl-2,3,7-trihydroxy-6-fluorone

Summary 9-Methyl-2.3.7-trihydroxy-6-fluorone has been used as a new colorimetric reagent for zirconium. The rose-red complex shows maximum absorption, against the reagent blank, at 500 nm and obeys Beer's law from 0.1 to 2.5 ppm. The optimum concentration range is from 0.66 to 2.5 ppm, where the per cent relative analysis error is 2.96. The composition of the complex, obtained from Job's method, indicates that the complex in solution contains the metal and the reagent in a ratio of 11. The instability constant of the complex is 1.07 · 10^–6.