Mass spectrometric in-situ determination of NO2 in gas mixtures by resonance enhanced multiphoton ionisation

One- and two-colour photoionisation spectra for NO₂ have been investigated using a time of flight mass spectrometer as detector to find the most efficient REMPI process for analytical applications. Two different inlet systems have been employed: a pulsed supersonic jet expansion stage and a flow reactor. Selective and sensitive mass spectrometric determinations of free NO₂ have been possible even in the presence of high concentrations of organic nitrates, HNO₃ and other NO₂ precursors. Employing two-colour (1+1′+1) excitation using a concentration of HNO₃≤5·10¹⁴ molecules/cm³ a detection limit of 5·10¹¹ molecules/cm³ has been found for NO₂ whereas in the absence of HNO₃ a detection limit of 5·10¹⁰ molecules/cm³ is reported.     

Kinetik und Mechanismus der Diazotierung, 15. Mitt.: Kinetik der anorganischen Startreaktion der Diazotierung

Zusammenfassung Es werden die Geschwindigkeitskoeffizienten der Primärreaktion der Diazotierung, nämlich der Bildung des Nitrosoacidiumions aus salpetriger Säure und Hydroxoniumion: HNO₂+H₃O⁺H₂O·NO⁺+H₂O bei verschiedenen Temperaturen bestimmt. Die thermodynamischen Aktivierungsgrößen dieser Urreaktion werden daraus errechnet.Die Resultate werden aus der Kinetik der Diazotierung des Anilins in Nitritpufferlösungen und in schwach sauren ungepufferten Lösungen geschöpft, bei welchen nur die beiden anorganischen Urreaktionen HNO₂+H₃O+H₂O·NO⁺+H₂O H₂O·NO⁺+NO_2–N₂O₃+H₂O kinetisch in Erscheinung treten.Originalvortrag vonHermann Schmid beim XVII. Internat. Kongr. Reine u. Angew. Chem. (München, 2. Sept. 1959).     

Synthesis and Characterization of Solid Coordination Complexes of Diamides for Uranium(VI) and Thorium(IV)

Five kinds of solid coordination complexes of uranium(VI) and thorium(IV) with the diamide (N,N,N,N-tetrabutylmalon-amide (TBMA), N,N,N,N-tetrabutylsuccinylamide (TBSA), N,N,N,N-tetrabutylglutaramide (TBGA), N,N,N,N-tetrabutyl-adipicamide (TBAA)) were synthesized. All these complexes of UO₂(NO₃)₂·TBMA, UO₂(NO₃)₂· TBSA, [UO₂(NO₃)₂·(TBGA^1/2)₂] _x , UO₂(NO₃)₂·TBAA and Th(NO₃)₄·2TBMA were characterized by elemental analysis, UV spectra, IR spectra and ¹³C NMR spectra. The coordination form and proposed structures of the complexes are also discussed.     

Kinetic Spectrophotometric Determination of Chromium (VI) by Oxidation of Sodium Pyrogallol-5-sulphonate by Hydrogen Peroxide

Summary. A new selective, sensitive, and simple kinetic method is developed for the determination of trace amounts of chromium (VI). The method is based on the catalytic effect of Cr(VI) on the reaction of sodium pyrogallol-5-sulphonate (PS) with hydrogen peroxide. The reaction is followed spectrophotometrically by tracing the oxidation product at 437nm within 1min after addition of H₂O₂. The optimum reaction conditions are PS (1.32·10^–3mol·dm^–3), H₂O₂ (0.32mol·dm^–3), HClO₄ (2.6·10^–3mol·dm^–3) at 25°C. Following this procedure, chromium (VI) can be determined with a linear calibration graph up to 0.25ng·cm^–3 and a detection limit of 0.024ng·cm^–3, based on the 3 criterion. The interference effect of several species was also investigated and it was found that the most common cations and anions do not interfere with the determination. The developed procedure was successfully applied to the determination of Cr(VI) and total Cr in river waters and total Cr in herbal samples.     

Integral heats of solution and enthalpies of ionization of 100% nitric acid at 298 K 3. Aqueous solutions of sulfuric acid containing 70–90% H2SO4 and ionization of HNO3 as a base

The integral heats of solution of 100% HNO₃ at =0.1mole/liter in aqueous solutions of H₂SO₄ of <90% by wt. were measured. A scheme was proposed and proved for ionization of HNO₃ as a base in 82–90% aqueous solutions of H₂SO₄, according to which un-ionized HNO₃ exists in the form of an aqueous solvate H₂O-HNO₃ and the ionized form as the ion pair NO₂ ⁺·HSO₄ ^–. The value of the enthalpy of ionization of nitric acid H(NO₂ ⁺ HSO₄ ^–)=H(NO₂ ⁺·HSO₄ ^–) drops from 2.05 at 89.99% H₂SO₄ to 0.18 kcal/mole in 84.07% H₂SO₄.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 306–310, February, 1990.     

Studies on the equilibrium uptake of some metal ions on a mixed and doped hydrous oxide using radiotracers

A highly sensitive and rapid method has been developed for the extraction-spectrophotometric determination of ultra trace amounts of americium. Americium(III) is selectively extracted from 1–10M HNO₃ medium with a mixture of (0.3M HDEHP+0.1M P₂O₅), both dissolved in xylene, and finally estimated in the organic phase itself absorptiometrically employing Arsenazo-III as the chromogenic reagent. A 60% dioxaneethanol mixture was used for optium colour development. Beer's law is obeyed in the concentration range 0.1–0.7 g Am cm^–3 and as little as 0.11 g Am cm^–3 could be determined with a precision better than ±2%. The molar absorptivity based on Am content is (3.599±0.049)·10⁵ dm³·mol^–1·cm^–1 at 648 nm which is incidentally the highest value reported as yet for its determination. The optimum concentration range, evaluated by Ringbom's method is 0.1–0.6 ppm Am. Common contaminants such as Al³⁺, Co²⁺, Cr³⁺, Fe³⁺, Ni²⁺, Zr⁴⁺, F^–, NO₃ ^–, and SO ₄ ^2- in fairly large quantities and moderate amounts of Pu⁴⁺, Th⁴⁺ and UO ₂ ²⁺ cause no interference in the final assay. Colour development is almost instantaneous and its intensity remains virtually constant for at least 48 hours.     

Preparation and characterization of a series of poly(acrylamide-co-acrylates), with a copolymer composition between 0–96.3 mol-% acrylate units with the same degree and distribution of polymerization

A series of linear poly(acrylamide-co-acrylates) (PAAm/AAcNa) has been prepared covering a copolymer composition between 0 and 96.3 mol% acrylate units, which have the same degrees of polymerization and chain length distributions. Measurements of viscosity and light scattering have proven that maximum coil dimensions of PAAm/ AAcNa in salt solutions are achieved at about 67 mole-% AAcNa. This so-called maximum behaviour was researched by measuring the radius of gyration, second virial coefficient, molecular weight, preferential solvation, viscosity and absorption bands of the copolymer series. Thus, an increase in the possible ways of arranging AAcNa-AAm-AAcNa units (via H-bonds) will lead to extended coil dimensions and therefore influence the viscosity. In addition, it can therefore be concluded from all these results that the maximum behaviour is real and not influenced by the different distributions of the samples. The copolymer composition can be easily determined by infra-red spectroscopy by use of a proposed relation.Abbreviations A₂ second virial coefficient (mole · cm³ · g^–2) - AAm acrylamide - AAcH acrylic acid - AAcNa sodium acrylate - c polymer concentration (g · cm^–3) - salt concentration (g · cm^–3), (Val · cm^–3) - C _LS critical concentration obtained by light scattering (g · cm^–3) - d _[] viscosity equivalent diameter of a sphere (nm) - E extinction - FW _s formula weights of salt - g _s gram of salt - g _p gram of polymer - GuaCl guanidinium chloride - h ^21/2 root mean square end-to-end distance (nm) - K optical constant for unpolarized incident light (mole · cm² · g^–2) - M molarity (mole · 1^–1) - M _w weight average molecular weight (g · mole^–1) - N _L Avogadro constant 6.023 · 10²³ mole^–1 - P _n number average degree of polymerization - P _w weight average degree of polymerization - PAAm poly(acrylamide) - PAAcH poly(acrylic acid) - PAAcNa poly(sodium acrylate) - PAAm/AAcNa poly(acrylamide-co-sodium acrylate) - R _[] Rayleigh ratio of the scattering at angle (cm^–1) - R _G ² _Z ^1/2 root mean square average radius of gyration (nm) - R _[] viscosity equivalent radius of a sphere (nm) - T temperature (°C), (K) - u excluded volume (cm³ · g^–1) - V molar volume (cm³ · mole^–1) - V _s partial specific volume - X mole fraction - (NH₂) oscillation of deformation - extinction coefficient - ₀ zero shear viscosity (Pa · s), (mPa · s) - _red reduced viscosity (cm³ · g^–1) - [] intrinsic viscosity (cm³ · g^–1) - _a constant of preferential solvation (g · g^–1) - ₀ wavelength of light in vacuo (nm) - chemical potential - v _as stretching vibration - scattering angle (°)     

Selective determination of copper with pyridoin phenylhydrazone as chromogenic extraction reagent

Summary The synthesis, characteristics and analytical applications of pyridoin phenylhydrazone are described. It reacts with copper(I) to produce an orange 11 complex ( _max=450 nm,=2.1×10⁴l· mole^–1·cm^–1) in aqueous ethanolic solution; it behaves as a cuproin type reagent. The orange complex can be extracted into amyl alcohol ( _max=440 nm,=2.0×10⁴l·mole^–1·cm^–1), and used for the spectrophotometric determination of trace amounts of copper. Interferences have been investigated.

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Zusammenfassung Synthese, Eigenschaften und analytische Anwendung von Pyridoin-phenylhydrazon wurden beschrieben. Es reagiert mit Cu(I) unter Bildung eines orange gefärbten 11-Komplexes in wäßrig-alkoholischer Lösung ( _max=450 nm,=2,1×10⁴l·mol^–1·cm^–1); das Reagens verhält sich ähnlich wie Cuproin. Der erwähnte Komplex läßt sich mit Amylalkohol extra-hieren ( _max=440 nm,=2,0×10⁴l·mol^–1·cm^–1) und zur spektrophoto-metrischen Bestimmung von Kupferspuren benützen. Auftretende Störungen wurden angegeben.

     

Arrangement and Diffusive Mobility of Extraframework Species in the Hydrated Ammonium Forms of Zeolites Clinoptilolite and Chabazite

The location and diffusive mobility of ammonium ions and water molecules in the channels of the NH₄substituted forms of the natural zeolites clinoptilolite (NH₄)_6.5[Al_6.5Si_29.5O₇₂] · 12.6H₂O and chabazite (NH₄)_9.6Ca_0.6Na_0.3[Al_11.1Si_24.9O₇₂] · 25.8H₂O were studied by Xray diffraction analysis and ¹H NMR spectroscopy. The arrangement of the extraframework subsystem was shown to be largely determined by hydrogen bonds N—H...O(H₂O) of length 2.7–2.9 . The diffusive mobility of the ions was found to correspond to abnormally low energy barriers, similar to those for H₂O diffusion. The activation parameters for the diffusion jumps of the ions and molecules are E(NH₄) = E(H₂O) = 31(2) kJ/mole, ₀(NH₄) = 2 · 10¹¹ sec^-1, ₀(H₂O) = 4 · 10¹² sec^-1 in NH₄chabazite and E(NH₄) = E(H₂O) = 25(1) kJ/mole, ₀(NH₄) = 2 · 10¹⁰ sec^-1, ₀(H₂O) = 3 · 10¹¹ sec^-1 in NH₄clinoptilolite. It is suggested that the development of ion and molecular diffusion is caused by the same defects, whose formation with temperature rise is controlled by Hbond rearrangement.     

CN chemiluminescence in N2 + CH4 Flowing afterglow at low temperatures

The spectra of flowing microwave post-discharge excited in N₂ and N₂ + CH₄(N₂ + C₂H₂) gas mixtures have been studied at low temperature (77 K). The molecular spectra of CN emitted by the collision-induced N + C and N + CH chemiluminescent reactions in the low-temperature afterglow system have been thoroughly investigated. The intensity of different CN (B²⁺-X²⁺) vibrational bands is very sensitive to low hydrocarbon concentration in nitrogen used as the working gas. Detection of hydrocarbon species has been demonstrated from concentrations of CH₄ and C₂H₂ in N₂ greater than 10¹⁰ molecules · cm^–3.     

Potassium ferrocyanide as a spectrophotometric reagent for the determination of uranium

Potassium ferrocyanide gives a colour reaction with U(VI), which is suitable for its determination. The complex absorbs in the wavelength range of 390–397 nm. The optimum pH range for colour development was 1.5–3.5. The molar absorptivity was found to be 4.65·10³ 1·mol^–1·cm^–1. Most of the anions up to 1000 g did not interfere. The method was made selective by extracting U(VI) first with DOSO from the mixture of interfering cations from 1–2M HNO₃ medium and then determining uranium in the back-extracted solution by developing the colour with ferrocyanide. 20 g/10 ml of U(VI) in the final solution could be satisfactorily determined within an RSD of ±2%.     

Crystal structure of the complex of dibenzo-30-crown-10 with dysprosium isothiocyanate

Crystalline [Dy(NCS)₃(dibenzo-30-crown-10)(H₂O)₂]·H₂O·MeCN can be obtained by slowly evaporating a reaction mixture of Dy(NCS)₃·nH₂O with dibenzo-30-crown-10 in a solution of acetonitrile. The material crystallizes in the monoclinic space groupP2₁/n, the cell parameters area=11.450(5),b=23.284(4),c=18.424(6)Å, =106.28(4)°,V=4715ų,M=968.47,D _x=1.36 g cm^–1, =17.80 cm^–1,F(000)=1972,Z=4.2740 independently observed [I3I] reflections were used in the final least-squares refinement leading to an agreement index ofR=0.085. The Dy(III) ion coordination geometry approximates a square antiprism, involving two water oxygens and three dibenzo-30-crown-10 oxygen atoms and three isthiocyanate nitrogens. Hydrogen bonds are formed between the two water molecules and four uncoordinated crown ether oxygen atoms. Supplementary Data relevant to this paper have been deposited with the British Library as Supplementary Publication No. SUP 82148 (22 pp.)     

Rb[C6H3(COOH)2(COO–)] · [C6H3(COOH)3] · 2H2O: Synthesis,Crystal Structure,and Properties

The salt Rb[C₆H₃(COO)₂(^–)] · [C₆H₃(COOH)₃] · 2H₂O (I) of trimesic acid was synthesized and its thermal stability and conductivity (10^–11 ohm^–1 cm^–1 at 298 K) were measured. Molecular and crystal structures of I were established by X-ray diffraction analysis. Hydrogen bonding system in complex I was detected by IR and Raman spectroscopies. X-ray diffraction data agree with vibration spectroscopy data.     

Characteristic of the Ag(II)/Ag(I) system in the presence of 2,2′:6′,2″-terpyridine in acetonitrile

Summary Composition of complexes of Ag(II) and Ag(I) ions with 2,2:6,2-terpyridine (tp) have been established. It has been found that the Ag⁺ ion forms only one complex Ag(tp)⁺ withtp in acetonitrile; its conditional formation constant: ₀₁=6.6·10⁴ has been determined by the potentiometric method. Equilibria and redox systems formed in solutions due to the complexation of Ag⁺ and Ag²⁺ and oxidation of Ag(II) complexes are described. Their formal potentials have been found by coulometric and voltamperometric examinations. The presence of the Ag(tp) ₂ ³⁺ ion in the anodic oxidized solutions of the complexes Ag(tp)(NO₃)₂ and Ag(tp)₂(NO₃)₂ has been proved. Properties of the system Ag(II)/Ag(I) in the presence of terpyridine in water and in acetonitrile have been compared.

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Charakteristik der Systeme Ag(II)/Ag(I) in Gegenwart von 2,2:6,2-Terpyridin in Acetonitril

Zusammenfassung Die Zusammensetzung der Komplexe von Ag(I)- und Ag(II)-Ionen mit 2,2:6,2-Terpyridin (tp) wurde bestimmt. Das Ag⁺-Ion bildet mittp in Acetonitril nur einen Komplex-Ag(tp)⁺. Seine Konditionalbildungskonstante ₀₁=6.6·10⁴ wurde mit Hilfe der potentiometrischen Methode bestimmt. Es wurden die Gleichgewichte und Redoxsysteme als Resultat der Komplexbildung von Ag(II)- und Ag(I)-Ionen und der Ag(II)-Komplexoxidation charakterisiert und die Formalpotentiale mittels Voltametrie und Coulometrie bestimmt. Die Gegenwart der Ag(tp) ₂ ³⁺ -Ionen wurde in anodisch oxydierten Lösungen der Komplexe Ag(tp)(NO₃)₂ und Ag(tp)₂(NO₃)₂ nachgewiesen. Die Eigenschaften des Systems Ag(II)/Ag(I) in Gegenwart von 2,2:6,2-Terpyridin in Wasser und in Acetonitril wurden verglichen.

     

Photometrische Bestimmung von Arsen und Phosphor in hochreinen Chemikalien

Zusammenfassung Optimale Bedingungen zur photometrischen Bestimmung von Spurengehalten Arsen und Phosphor nebeneinander wurden ermittelt. Die dem Verfahren zugrundeliegende Farbreaktion ist die Umsetzung von in saurer Lösung gebildeter Dodekamolybdatoarsen- bzw.-phosphorsäure mit Hydraziniumsulfat zu Arsen-bzw. Phosphor-Molybdänblau. Auf diese Weise sind Arsengehalte zwischen 1,1 und 10,0 g sowie 0,12 bis 8,0 g Phosphor zu bestimmen. Die Empfindlichkeit der Verfahren beträgt ₈₃₀=2,0·10⁴l·mol^–1·cm^–1 für As und ₈₃₀=2.6·10⁴ l·mol^–1·cm^–1 für P.Die Bestimmung beider Elemente nebeneinander gelingt dadurch, daß man nach der Summenbestimmung von As und P das Arsen aus der Analysenlösung durch Verflüchtigung als AsBr₃ entfernt oder es zu nicht mehr reaktionsfähigem As(III) reduziert. In der nun As-freien Lösung kann der P-Gehalt nach gleichem Verfahren ermittelt werden.Das Verfahren wurde zur Bestimmung von Arsen und Phosphor in hochreinen Chemikalien eingesetzt.

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Photometric determination of arsenic and phosphorus in high-purity chemicals

Summary Optimal conditions for the photometric determination of microgram amounts of arsenic and phosphorus are reported. The method bases on the reaction between molybdophosphoric or molybdoarsenic acid respectively, and hydrazinium sulphate to provide heteropoly blue.In this way arsenic can be determined within a range from 1.1 to 10.0 g and phosphorus within a range from 0.12 to 8.0 g. The absorptivities are ₈₃₀=2.0·10⁴l·mol^–1 ·cm^–1 for As and ₈₃₀=2.6·10⁴l·mol·cm^–1 for P, respectively.The simultaneous determination of As and P involves at first the determination of the sum of these elements and after reduction of arsenic to As(III) or volatilization as the bromide in a second step the determination of P in the same way.The method has been applied to the determination of arsenic and phosphorus in high-purity chemicals.

     

Über Verdazyliumsalze

Zusammenfassung Verdazyle reagieren mit FeCl₃ und anderen Metallhalogeniden in HCOOH unter Bildung von Doppelsalzen. Mit Tetranitromethan erhält man Verdazylium; C(NO₂)₃ ; und Verdazylium^;NO₃ ;. Verdazyliumsalze und Tetramethyl-p-phenylendiamin ergeben unter Elektronenübergang Verdazyle undWursters Blau. Dabei werden aus 2 diamagnetischen Verbindungen 2 paramagnetische Radikale gebildet. Die Absorptionsspektren verschiedenartig substituierter Verdazyliumsalze werden im Zusammenhang mit den Spektren der entsprechenden Verdazyle diskutiert.

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Verdazyls react with FeCl₃ and other metal halides in formic acid to give double-salts. Verdazylium;·C(NO₂)₃ ; and Verdazylium;NO₃ ; were obtained with tetranitromethane. Verdazyliumsalts and tetramethyl-p-phenylenediamine yield, in an electron transfer reaction, the corresponding verdazyls andWurster's-blue; i. e. two diamagnetic compounds react to give two stable paramagnetic species. The absorption spectra of different substituted verdazylium salts are discussed in relation to the spectra of the corresponding verdazyls.

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10. Mitt.:F. A. Neugebauer, Mh. Chem.97, 853 (1966).     

Sorption of gold, silver and mercury on cellulose

Summary Distribution coefficients of Au³⁺ on cellulose in 0.1 M NaNO₃ are rather high in the pH range 2 to 8 (D 5·10³ ml/g). They are appreciably lower in presence of NaCl or NaCN. Distribution coefficients of Ag⁺ are relatively low in 0.1 M NaNO₃, appreciably higher in presence of NH₄NO₃ (D 10³ ml/g in weakly acid media) and low in presence of NaCl, Na₂S₂O₃ or NaCN. Distrubution coefficients of Hg²⁺ are low in 0.1 M NaNO₃, and in presence of NaCN, but higher in 0.5 M NaCl (D 2·10² ml/ g). Responsible for the equilibria are mainly the special interactions between the predominant species with the sorbent under the given conditions, and less the complex equilibria in solution.

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Sorption von Gold, Silber und Quecksilber an Cellulose

Zusammenfassung Die Verteilungskoeffizienten von Au³⁺ an Cellulose in 0,1 M NaNO₃ sind ziemlich hoch im pH-Bereich 2 bis 8 (D 5·10³ ml/g). Sie sind erheblich niedriger in Gegenwart von NaCl oder NaCN. Die Verteilungskoeffizienten von Ag⁺ sind verhältnismäßig niedrig in 0,1 M NaNO₃, erheblich höher in Gegenwart von NH₄NO₃ (D 10³ mol/g in schwach saurem Medium) und niedrig in Gegenwart von NaCl, Na₂S₂O₃ oder NaCN. Die Verteilungskoeffizienten von Hg²⁺ sind niedrig in 0,1 M NaNO₃ sowie in Gegenwart von NaCN, aber höher in 0,5 NaCl (D 2·10² ml/g). Verantwortlich für die Sorption sind in erster Linie die speziellen Wechselwirkungen der vorherrschenden Spezies mit dem Sorbens unter den gegebenen Bedingungen, weniger die Komplexbildungsgleichgewichte in Lösung.

     

Inclusion complexes of the natural product gossypol. Crystal structures of gossypol complexes with benzene and chloroform as guests

The crystal structures of the lattice inclusion complexes of gossypol with benzene and chloroform have been determined by X-ray structure analysis. The crystals of (C₃₀H₃₀O₈)₂ · C₆H₆ (GPBNZ) are triclinic, space groupPI,a = 11.241(3),b = 14.986(4),c = 17.380(4) Å, = 98.89(2), = 99.86(2), = 98.91(2)°,V = 2800(2) ų,Z = 2,D _x = 1.32 g cm^–3, (CuK ) = 7.35 cm^–1. The structure has been refined to a finalR value of 0.050 for 6146 observed reflections. The crystals of C₃₀H₃₀O₈·CHCl₃ (GPCLF) are monoclinic, space groupC2/c,a = 28.464(4),b = 8.948(1),c = 26.480(4) Å, = 108.93(2)°,V = 6380(2) ų,Z = 8,D _x = 1.33 g cm^–3, (CuK) = 30.42 cm^–1. The structure has been refined to a finalR value of 0.100 for 1980 observed reflections.GPCLF forms an intercalate-type structure and GPBNZ a clathrate-type structure. There are, however, some similarities in the packing mode of the host molecules in these two structures. On a basis of comparison of the crystal packing of GPCLF and GPBNZ one can postulate that in the desorption process of the intercalate-type GPCLF complex an intermediate clathrate structure of the GPBNZ-type should be formed.     

Superionic conductivity in (BEDT-TTF)AgXiY

We have synthesized the organic conductor (BEDT-TTF)Ag_XI_Y (X 1.8 and Y 2.9). This compound has, in addition to high electronic conductivity (_{300 k} 5–10 ^–1 · cm^–1), significant ionic conductivity connected with the motion of silver ions. The value of this ionic conductivity at room temperature is 10^{–3 –1} · cm^–1. The activation energy for diffusion of Ag ions is equal to 0.2 eV.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 247–249, March–April, 1989.     

Simultaneous spectrophotometric determination of molybdenum and iron with salicylaldehyde thiosemicarbazone,and application to the analysis of steels

Summary Salicylaldehyde thiosemicarbazone reacts with molybdenum (VI) in mineral acid solution, in the presence of stannous chloride, to produce a 11 red-violet complex (_max=520 nm,=4.8×10³l·mole^–1·cm^–1). Iron(II and III) forms a green 12 complex, in ammonia-ammonium chloride solution (_max=590 nm,=1.7×10³l· mole^–1·cm^–1). Both complexes have been used with success in the photometric estimation of molybdenum and iron in mixtures. Molybdenum may be determined in presence of 40 times its weight of iron. Iron may be determined in presence of twice its weight of molybdenum. The reagent can be applied to the analysis of steels. The interferences of some metallic ions have been examined.

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Zusammenfassung Salicylaldehydsemicarbazon reagiert mit Molybdän(VI) in mineralsaurer Lösung in Gegenwart von Zinn(II)chlorid unter Bildung eines rot-violetten 11-Komplexes (_max=520 nm;=4,8·10³ l·Mol^–1·cm^–1). Eisen (II und III) bildet einen grünen 12-Komplex in einer Ammoniak-Ammoniumchloridlösung (_max=590nm;=l,7·10³ l·Mol^–1·cm^–1). Beide Komplexe eignen sich zur photometrischen Bestimmung von Mo und Fe in Gemischen. Mo kann in Gegenwart der 40fachen Gewichtsmenge Fe bestimmt werden, Fe läßt sich neben der doppelten Gewichtsmenge Mo bestimmen. Das Reagens eignet sich für die Stahlanalyse. Störungen durch metallische Fremdionen wurden überprüft.