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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.
通过用四酸与微波消解法溶解样品对比,建立了用硝酸、盐酸、氢氟酸、高氯酸分解样品,采用电感耦合等离子体质谱法(ICP-MS)测定稀土矿中16种元素含量。方法采用103Rh作为内标消除干扰,确定了最优测定条件,16种稀土元素检出限为0.0029-0.0099ng/mL,测定范围为0.0005-0.020%。精密度试验、加标回收试验及标准物质检测,结果验证了方法的可行性及准确性。该方法简单易操作,结果可靠,能满足实验分析要求。  相似文献   

3.
猪胰脏中铁钙镁铜铅锌镉锰钴镍的测定   总被引:2,自引:0,他引:2  
采用硝酸-过氧化氢在自动回流消化仪中消化猪胰脏,火焰原子吸收光度法测定铁、钙、镁、铜、锌、铅、镉、锰、钴、镍的含量。,方法简便,快速,结果令人满意,并对猪胰脏食用价值进行了评价。  相似文献   

4.
<正> The title com pound (HHOMP) has been synthesized with the pho-toinduced condensation of acetone and pyrrole in the presence of iodoaromatic hydrocarbons, and its molecular and crystal structures have been determined by X-ray analysis. C28H36N4, Mr = 428. 63, triclinic; space group P1; a =10. 165(3), b = 10. 185(2), c=13. 012(3)(?); α=85. 41(2), β=67. 84(2), γ= 89. 75(2)°; V = 1243 (?)3; Z = 2; D = 1. 145g. cm-3; μ= 0. 635cm-1; F (000) = 464. Although the HHOMP molecule twists, it is found that the four nitrogen atoms are still in a plane.  相似文献   

5.
张宏  孙仁安  李纳  阎杰 《结构化学》2006,25(3):279-284
1 INTRODUCTION In the later 60s of last century, silicon substituted for germanium to present as mainstream in semicon- ductor. The semi-conductive devices made by silicon have many advantages, for example, refractory pro- perty, high radioresistance, simple and stable process- ing technic, high machinability and low cost. So it was widely used to manufacture large power appara- tuses, for instance, digit and linear integrated circuit, large scale integrated circuit (LSI), etc. Thus, th…  相似文献   

6.
ICP-AES法测定铝中铁、硅、铜、镓、镁、锌、锰和钛   总被引:9,自引:0,他引:9  
用 50g L氢氧化钠溶液溶解铝样品 ,硝酸 (1 1 )酸化 ,以ICP AES测定其中铁、硅、铜、镓、镁、锌、锰和钛等 8种杂质元素。  相似文献   

7.
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   

8.
标题化合物C23H25对O3Cl是由邻氯苯甲醛与5,5-二甲基1,3-环己二酮在N,N-二甲基甲酸腹中反应而得。结构通过单晶X-射线衍射法确定,其晶体属于单科晶系,空间群=1632。晶体结构用直接法解出,使用全矩阵最小二乘法对原子参数进行修正,最后的偏离因子为R=0.054,Rw一0.063。在晶体结构中,吡喃环与苯环之间的两面角为92.43°。  相似文献   

9.
Twenty years ago, the landmark AM1 was introduced, and has since had an increasingly wide following among chemists due to its consistently good results and time-tested reliability--being presently available in countless computational quantum chemistry programs. However, semiempirical molecular orbital models still are of limited accuracy and need to be improved if the full potential of new linear scaling techniques, such as MOZYME and LocalSCF, is to be realized. Accordingly, in this article we present RM1 (Recife Model 1): a reparameterization of AM1. As before, the properties used in the parameterization procedure were: heats of formation, dipole moments, ionization potentials and geometric variables (bond lengths and angles). Considering that the vast majority of molecules of importance to life can be assembled by using only six elements: C, H, N, O, P, and S, and that by adding the halogens we can now build most molecules of importance to pharmaceutical research, our training set consisted of 1736 molecules, representative of organic and biochemistry, containing C, H, N, O, P, S, F, Cl, Br, and I atoms. Unlike AM1, and similar to PM3, all RM1 parameters have been optimized. For enthalpies of formation, dipole moments, ionization potentials, and interatomic distances, the average errors in RM1, for the 1736 molecules, are less than those for AM1, PM3, and PM5. Indeed, the average errors in kcal x mol(-1) of the enthalpies of formation for AM1, PM3, and PM5 are 11.15, 7.98, and 6.03, whereas for RM1 this value is 5.77. The errors, in Debye, of the dipole moments for AM1, PM3, PM5, and RM1 are, respectively, 0.37, 0.38, 0.50, and 0.34. Likewise, the respective errors for the ionization potentials, in eV, are 0.60, 0.55, 0.48, and 0.45, and the respective errors, in angstroms, for the interatomic distances are 0.036, 0.029, 0.037, and 0.027. The RM1 average error in bond angles of 6.82 degrees is only slightly higher than the AM1 figure of 5.88 degrees, and both are much smaller than the PM3 and PM5 figures of 6.98 degrees and 9.83 degrees, respectively. Moreover, a known error in PM3 nitrogen charges is corrected in RM1. Therefore, RM1 represents an improvement over AM1 and its similar successor PM3, and is probably very competitive with PM5, which is a somewhat different model, and not fully disclosed. RM1 possesses the same analytical construct and the same number of parameters for each atom as AM1, and, therefore, can be easily implemented in any software that already has AM1, not requiring any change in any line of code, with the sole exception of the values of the parameters themselves.  相似文献   

10.
11.
Eleven new quaternary rare-earth tellurides, CsLnZnTe3 (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Y), were prepared from solid-state reactions at 1123 K. These isostructural materials crystallize in the layered KZrCuS3 structure type in the orthorhombic space group Cmcm. The structure is composed of LnTe6 octahedra and ZnTe4 tetrahedra that share edges to form [LnZnTe3] layers. These layers stack perpendicular to [010] and are separated by layers of face- and edge-sharing CsTe8 bicapped trigonal prisms. There are no Te-Te bonds in the structure of these CsLnZnTe3 compounds so the formal oxidation states of Cs/Ln/Zn/Te are 1+/3+/2+/2-. Optical band gaps of 2.13 eV for CsGdZnTe3 and 2.12 eV for CsTbZnTe3 were deduced from single-crystal optical absorption measurements. A first-principles calculation of the density of states and the frequency-dependent optical properties was performed on CsGdZnTe3. The calculated band gap of 2.1 eV is in good agreement with the experimental value. A quadratic fit for the lanthanide contraction of the Ln-Te distance is superior to a linear one if the closed-shell atom is included.  相似文献   

12.
The preparation, properties, and reactions of the compounds named in the title are described, with particular reference to the possible participation of (p→d)π components in the bonding between the group IVB and the group VB elements.  相似文献   

13.
alpha-Aminoalkylcuprates prepared from alpha-lithio carbamates and CuCN.2LiCl participate in 1,4-addition reactions with alpha, beta-unsaturated esters, thiol esters, imides, and nitriles in poor to excellent yields depending upon the electron-withdrawing substituent and the substitution pattern of the unsaturated substrate. These reagents also undergo conjugate addition reactions with alpha,beta-alkynyl esters, sulfoxides, and nitriles and with alpha,beta-beta,gamma-unsaturated allenyl esters. Excellent stereocontrol is achieved in the conjugate additions of alpha-aminoalkylcuprates to the allenyl esters, while poor stereoselectivity results in the conjugate additions to the alkynyl derivatives. Deprotection and cyclization of the alkynyl adducts affords pyrrolin-2-ones, while similar treatment of the allenyl adducts affords 4-alkylidine- pyrrolidin-2-ones and pyrrolizidinones.  相似文献   

14.
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   

15.
建立了用ICP-AFS同时测定碳酸锂中11种微量金属杂质元素的方法。加入甲烷可改善检出限,方法简便,样品分析结果与AAS法结果一致。  相似文献   

16.
建立了一种用电感耦合等离子发射光谱(ICP-AES)法测定玻璃成份的简便、快速、准确、精密度好的方法.研究了样品的处理、标准样品的配制、谱线干扰等问题,并采用和基体匹配的方法消除基体的影响,进行了标准样品的分析、对照、精密度等试验,均取得了满意的结果.  相似文献   

17.
标题化合物C24H30O5是由邻甲氧基苯甲醛与5,5-二甲基-1,3-环己二酮在N,N-二甲基甲酰胺中反应而得。结构通过单晶X-射线衍射法确定,其晶体属于单斜晶系,空间群C2/c,a=33.942(6),b=7273(1),c=22667(4)A,β=128.989(9)°,Mr=398.50,V=4349(1)A3,Dc=1.2179·cm-3,Z=8,μ(MoKa)=840mm-1,F(000)=1712。晶体结构用直接法解出,经用全矩阵最小二乘法对原子参数进行修正,最后的偏离因子为R=0.043,Rw=0.052。在晶体结构中,存在一个分子间氢键。  相似文献   

18.
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   

19.
标题化合物C24H29NO4?1/2C2H5OH稨2O)由香兰素、5,5-二甲基-1,3-环己二酮、醋酸铵在微波辐射下干反应并经95%乙醇重结晶而得C24H29NO4穀2(C2H5OH稨2O)晶体。结构通过单晶X-射线衍射法确定,其晶体属单斜晶系,空间群P21/n, a = 9.810(2), b = 14.516(3), c = 17.008(3) ? b = 101.03(2), V = 2377.2(8) ?, Z = 4, Mr = 427.52, Dc = 1.195 g/cm3 , m(MoKa) = 0.082 mm-1, F(000) = 920。晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R = 0.0406, wR = 0.0892。X-射线衍射分析结果表明,吡啶环和与之稠合的2个六员环均为信封式构象。  相似文献   

20.
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   

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