首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Zusammenfassung Für 14 Elemente wird eine universelle Methode beschrieben. Durch Zusatz von Lanthan und Cäsium werden die physikalischen, chemischen und Ionisations-Störungen in der Flammen-AAS ausgeschaltet. Es wird gezeigt, daß diese Methode für sehr unterschiedliche Stoffe mit Erfolg angewendet werden kann, und gleichzeitig die Genauigkeit des Routinemeßverfahrens nicht beeinträchtigt wird. Nur in Ausnahmefällen muß die Additionsmethode benutzt werden.
Determination of calcium, magnesium, strontium, potassium, sodium, lithium, iron, manganese, chromium, nickel, copper, cobalt, zinc and cadmium by flame AASA universal method for the analysis of waters, coals, ashes, ores, rocks, building materials, metals and similar samples
Summary A universal method is described for 14 elements. By addition of lanthanum and caesium the physical, chemical and ionization interferences in the flame AAS are eliminated. It is demonstrated that this method can be applied successfully for very different materials and simultaneously the precision of the standard measuring method is not affected. Only in exceptional cases the addition method has to be applied.


Herrn Prof. Dr. W. Schuhknecht, dem langjährigen Leiter des Zentrallabors der Saarbergwerke AG (1948–1972) zum Gedenken

Für die sorgfältige Durchführung von Säure- und Schmelzaufschlüssen sowie seine nützlichen Hinweise bei der Korrektur des Manuskriptes möchte ich Herrn Lothar Kiefer meinen besonderen Dank aussprechen.  相似文献   

2.
Using a recently developed procedure for optimizing parameters for semiempirical methods,1 PM3 has been extended to a total of 28 elements. Average ΔHf errors for the newly parameterized elements are Be: 8.6, Mg: 8.4, Zn: 5.8, Ga: 14.9, Ge: 11.4, As: 8.5, Se: 11.1, Cd: 2.6, In: 11.3, Sn: 9.0, Sb: 13.7, Te: 11.3, Hg: 6.8, Tl: 6.5, Pb: 7.4, and Bi: 10.9 kcal/mol. For some elements the paucity of data has resulted in a method, which, while highly accurate, is likely to be only poorly predictive.  相似文献   

3.
Zusammenfassung Die Phenylverbindungen von Thallium, Selen, Tellur, Quecksilber, Arsen, Antimon, Wismut und Zinn sind zur gas-chromatographischen Analyse dieser Elemente geeignet. Sie entstehen bis auf Thalliumtriphenyl quantitativ beim Umsatz der aus saurer Lösung extrahierten Diäthyldithiocarbamidate mit magnesiumorganischen Verbindungen. Gas-chromatographisch lassen sich die Phenylverbindungen aller acht Elemente mit einer Säule unter Verwendung eines Temperaturprogramms trennen. Im Falle des Quecksilberdiphenyls konnte keine vollständige Elution erreicht werden.Vortrag anläßlich der Tagung Euroanalysis I, 28. 8.–1. 9. 1972 in Heidelberg.  相似文献   

4.
An accurate and simple method has been developed for the determination of Pt, Ru, Ir and other elements employing instrumental neutron activation analysis (INAA). Nondestructive analysis has been carried out for the determination of these elements in different rock samples such as Dolerite, Dyke Dolerite, Country Basalt, Hyaloclastite, Trachyte, Ijolite, Spillite, Diorite and Lamprophyre from various locations like Daman, Tapti, Murud, Talasari, Ranala and Bassein in Maharashtra state. High flux provided by the CIRUS reactor (1×1013 n cm–2s–1) has been used for thermal neutron bombardment followed by radioassaying of the (n,) products on a HPGe detector coupled to a PC-based MCA unit.  相似文献   

5.
Acetamidiniumhexafluorometallates of Aluminium, Gallium, Indium, Vanadium, Chromium, Manganese, Iron and Cobalt The title compounds were crystallized from F-containing aqueous solutions of their hexafluoro-metallate acids by adding acetamidine. Their unit cells were determined and the thermal decomposition was investigated thermoanalytically. The crystal structure of [CH3C(NH2)2]3AlF6 was determined: Space group P41212/P43212, a = 8,987(1), c = 17,894(3) Å, R = 0,054. The unit cell parameters: .  相似文献   

6.
7.
An analysis of the results of the fluorescence spectrum investigation of all-trans-deca-1,3,5,7,9-pentaene and t,C,t,T,t,T,t-deca-1,3,5,7,9-pentaene in an n-decane matrix [B.E. Kohler, V. Terpougov, J. Chem. Phys. 108 (1998) 9586–9593] has been performed using scaled quantum mechanical force field (SQM-FF) methodology at the HF/6-31G level. The measured vibronic wavenumbers were assigned taking into account the results of quantum-chemical predictions of the vibrational spectra for all-trans-deca-1,3,5,7,9-pentaene and t,C,t,T,t,T,t-deca-1,3,5,7,9-pentaene. Results from additional calculations at the MP2(FC)/aug-cc-pVDZ and B3LYP/6-311++G(d,p) levels are also reported.  相似文献   

8.
Zusammenfassung Es wurden Verfahren zur Bestimmung dieser 10 Elemente in Ammoniumphosphat bzw. Phosphorsäure entwickelt. Zur Anreicherung wurde die Extraktion der Dithiocarbamate, 8-Hydroxychinolinate und Pyrazolonate der Elemente angewendet. Die Bestimmung der Elementkonzentrationen erfolgte mittels Flammen-AAS und OES. Die nach den verschiedenen Verfahren erhaltenen Ergebnisse sind in guter Übereinstimmung. Die Nachweisgrenzen der einzelnen Elemente liegen, abhängig vom Verfahren, zwischen 1.10–5 und 5.10–8%.
Determination of microtraces of Bi, Co, Fe, In, Mn, Ni, Pb, Cu, Sb and Zn in phosphoric acid and ammonium phosphate.I. Flame atomic absorption and optical emission spectroscopic determination after preconcentration of the microtraces by extraction
Summary Two different methods are applied to the determination of the trace element content in ammonium phosphate, or phosphoric acid, respectively. The procedures involve two separate extraction systems based on ammonium pyrrolidine-dithiocarbamate, 8-hydroxyquinoline and 1-phenyl-3-methyl-4-benzoylpyrazolone-5, and two spectroscopic techniques — AAS and OES. The results obtained by the different methods are in good agreement. The detection limits of the separate trace elements vary from 1×10–5 to 5×10–8%.
  相似文献   

9.
The distribution ratios of two isomeric 5, 7, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane, tet c and tet d, in several solvent systems at 25.0°C as functions of hydrogen ion concentration were determined. The protonation constants and the distribution constants of these macrocyclic ligands and their protonated species were obtained from the variations of the distribution ratios in the range of 6<–log [H+]<14.  相似文献   

10.
Summary The removal of trace elements from dilute water solutions by hydroxide precipitates was investigated. The co-precipitation yields of manganese, cobalt, ruthenium, europium and protactinium onto beryllium, zinc, iron, lanthanum and titanium hydroxides were studied in the pH region from 3 to 11, while those of manganese, cobalt, yttrium, zirconium, niobium, ruthenium, europium, and protactinium onto the same hydroxides were investigated in sea-water media. The influence of some other factors, such as the presence of neutral electrolyte and NH4 + ions, aging of hydroxide precipitates etc. on the co-precipitation yields were also examined.
Zusammenfassung Die Entfernung von Spurenelementen aus verdünnten wäßrigen Lösungen durch Hydroxidniederschläge wurde untersucht. Die mitgefällten Anteile Mn, Co, Ru, Eu und Pa in den Hydroxiden von Be, Zn, Fe, La und Ti wurden im pH-Bereich 3–11 untersucht, während die Anteile von Mn, Co, Yt, Zr, Nb, Ru, Eu und Pa in den gleichen Hydroxiden in Meerwasser studiert wurden. Der Einfluß einiger anderer Faktoren auf die Mitfällung, wie die Anwesenheit neutraler Elektrolyte und von NH4-Ionen, die Alterung der Hydroxidniederschläge usw. wurden ebenfalls geprüft.
  相似文献   

11.
X-Ray studies of the mixed nitride phases indicate complete miscibility in all cases. Lattice parameters generally showed negative deviations from the additivity rule.
Teilauszug aus der Dissertation des Dipl.-Ing.J. Waldhart an der Technischen Universität Wien, Österreich.  相似文献   

12.
The title compounds have been prepared in low yields starting with cis-(CH3CN)3-Mo(CO)3 or Mo(CO)6 (photochemical route). The new complexes are generally less stable than the corresponding hexaalkylborazine-chromium compounds and react very smoothly with Lewis bases by cleavage of the borazine-metal bond. The IR.-spectra indicate the similarity of type of bonding in hexaalkylborazine-molybdenum and -chromium complexes.  相似文献   

13.
Summary The analysis of ashes being of increasing importance, a reference material was prepared from fly ash of a city waste incinerator. The procedures of preparation, homogeneity and stability testing are described as well as the way of certification of elements of major importance: Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Zn, Sb, Se and Tl.
Zertifizierung der Gehalte an Cd, Co, Cu, Fe, Hg, Ni, Pb, Zn, Sb, Se, Tl und Cr in einer Stadtmüll-Verbrennungsasche
Zusammenfassung Da die Analyse von Aschen zunehmend an Bedeutung gewinnt, wurde von der Flugasche einer Stadtmüll-Verbrennungsanlage ein Referenzmaterial hergestellt. Die Methoden der Herstellung sowie der Homogenitätsund Stabilitätsprüfung werden beschrieben und die Art der Zertifizierung der Elemente von hauptsächlicher Bedeutung aufgezeigt (Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Zn, Sb, Se, Tl).
  相似文献   

14.
This paper described the continuation of the work of Part I dealing with a microanalytical method in which the sample is introduced into a flame using an electrically heated platinum loop. This device is used in connection with an atomic absorption (AA) spectrometer. The detection limits are one to two orders of magnitude better than those of conventional flame AAS. The reproducibility depends on the element and is in general 3–5% (relative standard deviation) for concentrations in the ngml range. The platinum loop method can be also applied for flame emission analysis of small amounts of sample or the determination of low concentrations (alkalis). This application gives access to determinations in the lower ng or the pg range (detection limit of lithium: 0.6 pg).  相似文献   

15.

AbstractsGeneral analytical chemistry

Fundamentals, methods, apparatus, reagents, automation, data processing  相似文献   

16.

AbstractsGeneral analytical chemistry

Fundamentals, methods, apparatus, reagents, automation, data processing  相似文献   

17.

Referate1 Allgemeine analytische Chemie

1.1 Grundlagen, Methoden, Apparate, Reagentien, Automation, Datenverarbeitung  相似文献   

18.
Quaternary Magnesium Iridium Borides Mg2XIr5B2 with X = Be, Al, Si, P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As – a Substitution Variant of the Ti3Co5B2 Type of Structure The compounds Mg2XIr5B2 with X = Be, Al, Si, P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge and As crystallize tetragonally with Z = 2 in the space group P4/mbm. The lattice constants are in the range a = 9.199 Å, c = 2.880 Å for Mg2BeIr5B2 und a = 9.406 Å, c = 2.953 Å for Mg2TiIr5B2 (further lattice constants are given in Table 1). X-ray structure determinations carried out with single crystals of the Si-and the P-compounds showed that a substitution variant of the Ti3Co5B2 type of structure is formed. According to X-ray powder photographs the other compounds are isotypic. In the compounds with X = P and As the X-siteset is only occupied at about 70% and 80% respectively.  相似文献   

19.
[Au(C6F5)(tht)], which on reaction with P, O, S-coordinating phosphines in CH2Cl2 medium leads to [Au(C6F5)(X)] [X = PPh3 H, (1a), oMe, (1b), pMe, (1c), mMe, (1d), AsPh3 (2), OPPh3 (3), SPPh3 (4), dppm, dppe, dppa = diphenylphosphino-methane,-ethane,-ammine(5, 6, 7), TPA = 135-tetraaza-7-phosphino adamentane(8), Py4H (9a), 4Bu (9b), 4Ac (9c), tht = tetrahydrothiophen, C6F5 is the pentafluorophenyl ring]. The maximum molecular peak of the corresponding molecule is observed in the ESI mass spectrum. I.r. spectra of the complexes show –C = C– and C6F5 stretching near at 1610 and 1510, 955, 800 cm−1. The 1H-n.m.r. spectra as well as 31P- (1H)n.m.r. suggest solution stereochemistry, proton movement, phosphorus proton interaction. 13C-n.m.r. spectrum reflect the carbon skeleton in the molecule. In the 1H–1H COSY spectrum of the present complexes and contour peaks in the 1H–13C-HMQC spectrum, assign the solution structure and stereoretentive conformation in each step.  相似文献   

20.
Polycrystalline Ba2LnSbO6 (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) are cubic, perovskite-type compounds, space group Fm3m (No. 225), Z = 4, with a values from a = 8.544(2) Å for Ba2NdSbO6 to a = 8.368(1) Å for Ba2YbSbO6. X-ray diffraction data for all the compounds and the results of magnetic measurements for two of them are given.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号