电感耦合等离子体质谱法测定水中低浓度铁受钙干扰的消除

采用电感耦合等离子体质谱法测定水中小于0.06 mg·L-1铁量时受到共存的钙(40mg·L-1)的严重干扰。经验证,钙的干扰可借以下途径消除:①采用碰撞池和56Fe、57Fe两同位素中的任一种,钙的干扰均可忽略不计。②如采用非碰撞池,则钙的干扰将因铁与其共存钙的质量浓度的不同而变化:(a)当cFe<0.10mg·L-1,cCa<1mg·L-1,并采用57Fe同位素时,钙的干扰可以忽略;(b)当cFe<0.10mg·L-1,cCa>1mg·L-1时,采用两同位素中的任一种都无法克服钙的严重干扰;(c)当cFe>0.10mg·L-1,cCa<5mg·L-1,无论采用同位素56Fe或57Fe,钙的干扰都不明显,而如cCa>5mg·L-1时,则只能用同位素56Fe才可避免钙的干扰。     

非完全消化-火焰原子吸收光谱法测定润滑油中钙锌

在低温加热的条件下,油样用浓硝酸消化,所得试液中加入适量Triton X-100及Tween 80使乳化从而得到均匀的透明或半透明的呈橙黄色或黄绿色的试样溶液,供火焰原子吸收光谱法(FAAS)测定钙及锌.对非完全消化所用的酸和乳化剂的选择和FAAS测定中的化学干扰、背景干扰以及空白溶液及试样溶液粘度的一致性等分析务件进行了试验和优化.钙及锌两元素的线性范围依次为0～12 mg·L-1和0～1.6 mg·L-1,检出限(3σ/s)依次为0.14 mg·L-1及0.018 mg·L-1.此方法应用于润滑油实样分析,所得两元素分析结果的RSD(n=6)值均小于5%,回收率均在100.0%～102.1%之间.     

分光光度法与火焰原子吸收光谱法测定钢中硼的比较

提出了萃取-分光光度法和火焰原子吸收光谱法测定钢中硼的两种方法,比较了两者的线性范围、检出限、样品测定结果等.试验发现:分光光度法和火焰原子吸收光谱法在硼含量分别为0.11～3.2 mg·L-1和0.05～3.24 mg·L-1范围内时,吸光度与其质量浓度呈线性关系,检出限(3S/N)分别为0.033,0.036 mg·L-1.经检验,两种方法的测定结果之间无显著性差异.     

微波消解样品-火焰原子吸收光谱法测定人发中10种微量元素

0.200 0g人发试样经5.0mL硝酸和1.0mL过氧化氢消解,用火焰原子吸收光谱法测定其中钙、铁、锌、锰、铜、铅、镉、钴和镍的含量,用氢化物发生-火焰原子吸收光谱法测定硒的含量。测定钙时,加入镧溶液,以消除共存物的干扰。用10种元素的标准溶液制作了各自的标准曲线,所得线性回归方程的相关系数在0.998 5～0.999 9之间,检出限(3σ)为0.002～0.009mg.L-1之间。以人发样品为基底,加入一定量10种元素的标准溶液做回收试验,得到回收率在95.6%～103.5%之间。     

电感耦合等离子体原子发射光谱法测定中药材中钙、镁和磷

应用电感耦合等离子体原子发射光谱法同时测定了3种中药材(淫羊藿、杜仲及肉苁蓉)中生物元素钙、镁及磷的含量.用干灰化法处理药材试样,残渣用硝酸溶解并以水定容后备作AES测定.选择波长为 317.933,280.271 及 214.914 nm 3条分析谱线分别测定钙、镁及磷3元素的含量.3元素的检出限依次为 10.0,1.6 及 140.0 mg·L-1.应用所提出的方法测定了上述3种中药材中的钙、镁和磷的含量,算得 3 元素的相对标准偏差(n=7)均小于3%.     

电感耦合等离子体原子发射光谱法测定铸造铝合金中磷含量

提出了电感耦合等离子体原子发射光谱法测定铸造铝合金中磷含量的方法。铸造铝合金称样0.500 0g,用硝酸(1+1)溶液12mL和氢氟酸4mL溶解。选择波长为213.618nm谱线作为测定磷的分析线。磷的质量浓度在4.00mg·L-1以内与其发射强度呈线性关系,方法的检出限(3s/k)为0.020mg·L-1。方法用于分析5个铸造铝合金标准物质,测定值与认定值相符,相对标准偏差(n=6)在0.43%～2.2%之间,回收率在94.0%～109%之间。     

电感耦合等离子体原子发射光谱法测定五氧化二钒中19种杂质元素

采用盐酸消解五氧化二钒样品及其中所含可溶性杂质,再以无水碳酸钾与硼酸高温熔融不可溶性杂质,然后以盐酸溶解熔块,合并溶液后以用电感耦合等离子体原子发射光谱法测定杂质元素铌、锆、钛、钨、硅、铝、钼、钴、铬、镍、铜、铅、镉、砷、磷、铁、锰、钙和镁的含量。试验了基体元素和共存元素对测定的干扰,优化各元素的分析谱线,运用同步背景校正消除基体影响。19种元素的检出限在10～225μg.L-1之间,背景等效浓度在5～150μg.L-1之间。方法用于分析五氧化二钒样品,测定结果与其它化学分析方法测定值一致;分析五氧化二钒标准样品(GSBH 42015-96)的测定值与标准值相一致。     

表面活性剂增敏火焰原子吸收光谱法测定铝合金中铜

以锌空心阴极灯作为光源,用火焰原子吸收光谱法测定了铝合金中铜量。试样溶解于盐酸及硝酸中,并在含有硝酸(1+1)溶液3.0mL的50mL酸性溶液中进行测定。在试样溶液中还加入5g.L-1乳化剂OP溶液1.5mL作为增敏剂,30g.L-1镧(Ⅲ)溶液4.0mL作为释放剂;后者的加入使硅、铝、镁、镍、锰、钙、钴及铁的允许共存量有显著提升。按此条件分析过程中不存在背景吸收干扰。测得吸光度与相应铜(Ⅱ)的质量浓度在6.0mg·L-1以内呈线性关系,其检出限(3s/k)为0.011 2 mg·L-1。应用此方法分析了一件铝合金试样,测得其铜量的平均值为1.656mg·g-1,测定值的相对标准偏差(n=6)为1.3%。同一试样,改用铜空心阴极灯进行分析,测得铜量的平均值为1.670mg·g-1,相对标准偏差(n=6)为0.92%。t-检验结果表明:用两种不同光源所测得的铜量的结果之间无显著性差异。     

石墨炉原子吸收光谱法间接测定保健食品中维生素B12

保健食品经浓硝酸-过氧化氢(10+3)混合溶液微波消解后,加入盐酸(1+99)溶液使维生素B12中的钴离子完全离解出来,再用石墨炉原子吸收光谱法测定钴离子,据此间接测定保健食品样品中维生素B12的含量.对仪器的工作条件测定波长、灯电流、载气流量作了详述,还对各种对测定有影响的因素,包括盐酸浓度、基体改进剂的种类、石墨炉的工作条件、共存离子的干扰等也作了试验并予以优化选择.维生素B12的质量分数在0.31～4.6 mg·kg-1范围内与吸光度内呈线性关系.方法检出限(3S/N)为0.093 mg·kg-1,在1.0,2.0,4.0 μg·L-1的标准加入水平下进行了回收试验和精密度试验,所得回收率在96.9%～105.0%之间.测定值的相对标准偏差(n=7)小于2.1%.     

火焰原子吸收光谱法测定铝合金中铬

铝合金样品溶于盐酸及过氧化氢中,其铬量用火焰原子吸收光谱法测定.采用空气-乙炔富燃火焰原子化并用锶盐作干扰抑制剂.铬的工作曲线浓度范围为1.2～20.0 mg·L-1(r=0.999).方法应用于4个铝合金标样的测定,所得结果与标准值相符.方法的RSD(n=5)值在2.1%～4.2%之间,回收率在97%～104%之间.     

Synthesis and structure of hydroxyisoxazolidines and derivatives of hydroxylamine and alkenals

The reactions of N-substituted hydroxylamines with alkenals serve as a method for the synthesis of the corresponding 2-substituted 3(5)-hydroxyisoxazolidines. The reaction pathway is determined by the nature of the substituent attached to the nitrogen atom. Ring-chain isomerism has been detected in these newly obtained compoundsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1270–1276, September, 1987.     

Investigation of adhesion and mobility of polyurethane and epoxy-rubber glues and adhesives

The values of activation parameters in uncured and cured epoxy resins, rubbers, and blends thereof are investigated. The dependences of activation energy and adhesion strength of epoxy-rubber compositions on rubber content are determined. The correlation of adhesion and activation energy values for polyurethane rubber and epoxy-rubber compositions is shown.     

Crystal and molecular structure of aroyl- and acetylhydrazones of acet- and benzaldehydes

Aroyl- and acetylhydrazones of acet- (I) and benzaldehydes (IV) and benzoylhydrazones of acet- (II) and benzaldehydes (III) were studied by x-ray structural and quantum-chemical methods in order to establish their structures. Compund (I) was the EEZ structure in the crystal. Calculations and spectral data showed that the EEE form occurs in nonpolar solvents and in the gas phase. According to crystallographic data molecules (I)–(IV) are the E-isomers (relative to the N-N bond) and the hydrazone fragments are planar. Intermolecular N-H...O H-bonds from in the crystals. The data obtained suggest that the majority of acylhydrazones are conformationally rigid on dissolution although exceptions do occur. Apparently the reasons for the difference of acetyl- and benzoylhydrazones in electrocarboxylation reactions are electronic and not steric factors.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 75–81, January, 1991.     

Mass and NMR spectra of haplophyllidine and perforine and of their derivatives

Conclusions The mass and NMR spectra of haplophyllidine, perforine, and their derivatives have been studied. The influence of the open and cyclic forms of the molecular ion on the nature of the fragmentation has been discussed. The main routes of fragmentation of the compounds considered are due to the presence of substituents at C₈ and C₄.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 273–279, 1969     

Synthesis and characterization of triazenide and triazene complexes of ruthenium and osmium

Triazenide [M(eta2-1,3-ArNNNAr)P4]BPh4 [M = Ru, Os; Ar = Ph, p-tolyl; P = P(OMe)3, P(OEt)3, PPh(OEt)2] complexes were prepared by allowing triflate [M(kappa2-OTf)P4]OTf species to react first with 1,3-ArN=NN(H)Ar triazene and then with an excess of triethylamine. Alternatively, ruthenium triazenide [Ru(eta2-1,3-ArNNNAr)P4]BPh4 derivatives were obtained by reacting hydride [RuH(eta2-H2)P4]+ and RuH(kappa1-OTf)P4 compounds with 1,3-diaryltriazene. The complexes were characterized by spectroscopy and X-ray crystallography of the [Ru(eta2-1,3-PhNNNPh){P(OEt)3}4]BPh4 derivative. Hydride triazene [OsH(eta1-1,3-ArN=NN(H)Ar)P4]BPh4 [P = P(OEt)3, PPh(OEt)2; Ar = Ph, p-tolyl] and [RuH{eta1-1,3-p-tolyl-N=NN(H)-p-tolyl}{PPh(OEt)2}4]BPh4 derivatives were prepared by allowing kappa1-triflate MH(kappa1-OTf)P4 to react with 1,3-diaryltriazene. The [Os(kappa1-OTf){eta1-1,3-PhN=NN(H)Ph}{P(OEt)3}4]BPh4 intermediate was also obtained. Variable-temperature NMR studies were carried out using 15N-labeled triazene complexes prepared from the 1,3-Ph15N=N15N(H)Ph ligand. Osmium dihydrogen [OsH(eta2-H2)P4]BPh4 complexes [P = P(OEt)3, PPh(OEt)2] react with 1,3-ArN=NN(H)Ar triazene to give the hydride-diazene [OsH(ArN=NH)P4]BPh4 derivatives. The X-ray crystal structure determination of the [OsH(PhN=NH){PPh(OEt)2}4]BPh4 complex is reported. A reaction path to explain the formation of the diazene complexes is also reported.     

Preparation and characterization of diarylphosphazene and diarylphosphinohydrazide complexes of titanium, tungsten and ruthenium and phosphorylketimido complexes of rhenium

Reaction of the proligand Ph2PN(SiMe3)2 (L1) with WCl6 gives the oligomeric phosphazene complex [WCl4(NPPh2)]n, 1 and subsequent reaction with PMe2Ph or NBu4Cl gives [WCl4(NPPh2)(PMe2Ph)] (2) or [WCl5(NPPh2)][NBu4] (3), respectively. DF calculations on [WCl5(NPPh2)][NBu4] show a W=N double bond (1.756 A) and a P-N bond distance of 1.701 A, which combined with the geometry about the P atom suggests, there is no P-N multiple bonding. Reaction of L1 with [ReOX3(PPh3)2] in MeCN (X = Cl or Br) gives [ReX2(NC(CH3)P(O)Ph2)(MeCN)(PPh3)](X = Cl, 4, X = Br, 5) which contains the new phosphorylketimido ligand. It is bound to the rhenium centre with a virtually linear Re-N-C arrangement (Re-N-C angle = 176.6 degrees, when X = Cl) and there is multiple bonding between Re and N (Re-N = 1.809(7) A when X = Cl). The proligand Ph2PNHNMe2(L2H) reacts with [(C5H5)TiCl3] to give [(C5H5)TiCl2(Me2NNPPh2)] (6). An X-ray crystal structure of the complex shows the ligand (L2) is bound by both nitrogen atoms. Reaction of the proligands Ph2PNHNR2[R2 = Me2 (L2H), -(CH2CH2)2NCH3 (L3H), (CH2CH2)2CH2 (L4H)] with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave [RuCl2(eta6-p-MeC6H4iPr)L] {L = L2H (7), L3H (8), L4H (9)}. The X-ray crystal structures of 7-9 confirmed that the phosphinohydrazine ligand is neutral and bound via the phosphorus only. Reaction of complexes 7-9 with AgBF4 resulted in chloride ion abstraction and the formation of the cationic species [RuCl(6-p-MeC6H4iPr)(L)]+ BF4- {(L = L2H (10), L3H (11), L4H (12)}. Finally, reaction of complex 6 with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave the binuclear species [(eta6-p-MeC6H4iPr)Cl2Ru(mu2,eta3-Ph2PNNMe2)TiCl2(C5H5)], 13.     

Glycolate and Thioglycolate Complexes of Rhenium and Their Oxidative Elimination of Ethylene and of Glycol

Selenium dioxide and osmium tetroxide are effective reagents and catalysts for olefin oxidation, although, owing to their toxicity, reservations remain as to their applicability.^[1] We are therefore seeking more easily handled metal oxides that are soluble in organic solvents and that are as effective as osmium tetroxide in carrying out stereospecific cis hydroxylation of olefins. The rhenium(VII ) oxide 1 , which has meanwhile become readily accessible, is a favorable candidate.^[2]     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。