肝中茚满二酮类杀鼠剂固相萃取-紫外导数光谱检测法

报道了肝中敌鼠，氯敌鼠，杀鼠酮三种茚满二酮类杀鼠剂的题示检测方法。肝匀浆先用乙腈或二甲基甲酰胺浸提，浸提液用６％高氯酸溶液或０．１ｍｏｌ／Ｌ氢氧化钠溶液稀释，然后加入ＧＤＸ１０１大孔树脂萃取，肝中杀鼠剂萃取率约８０％，检出限为１μｇ／ｇ以下     

氯化三辛基甲基胺萃取原子吸收法测定微量锑的研究

本文在ＫＩ－Ｈ２ＳＯ４体系中，研究了锑的碘络阴离子的萃取行为，并结合火焰原子吸收法测定了微量锑，萃取体积比（Ｖ水／Ｖ有）为２０，线性范围为０－２μｇ／ｍｌ，锑的特征浓度为０．５μｇ／ｍｌ／１％吸收，检出限为０．１μｇ／ｍｌ。     

固相萃取—紫外导数光谱法测定血中茚满二酮类抗凝血杀鼠剂

报道了血中敌鼠、氯敌鼠、杀鼠酮的题示测定方法。该法操作简便快速、回收率高，灵敏度较高，萃取使用国产高分子多孔微球ＧＤＸ３０１，价廉易得。三种杀鼠剂以１０ｍｇ／Ｌ量分别加于血中，回收率依次为１００．５％±２．９％、１０１．５％±１．３％及９９．３％±１．５％；血中三种杀鼠剂检出限分别为０．４、０．６及０．４ｍｇ／Ｌ。     

萃取—缝管原子捕集原子吸收法测定水中碲（Ⅳ）和磅（Ⅵ）

研究了碲（Ⅳ）和碲（Ⅵ）在ＤＤＴＣ－ＣＣｌ４体系中的萃取和反萃取行为，并用缝管原子捕集技术结合火焰原子吸收法测定了水样中的碲（Ⅳ）和碲（Ⅵ），特征浓度为１．２ｇ／Ｌ／１％吸收，检出限０．２μｇ／Ｌ，相对标准偏差１．７％，富集倍中达１００％。     

PBA光纤化学传感器在线监测家兔口服呋喃妥因的尿药浓度

芘丁酸光纤化学传感器（ＰＢＡ—ＦＯＣＳ）用于在线测定家兔口服呋喃妥因后排出尿液中的药物浓度。方法的检出限为１．３μｇ／ｍＬ，线性范围１～１００μｇ／ｍＬ，精密度（ＲＳＤ）１．５～３．５％，回收率在９５．０～１００％之间。４只雄性家兔的尿药浓度—时间曲线显示达峰时间为３．５ｈ，６ｈ累积尿药排出百分率为２１％。实验结果显示传感器、测定池和仪器系统设计合理。可实时、在线测定生物体液中的药物浓度并达到实用水平。     

2，3－二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐。测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０～１５００μｇ／Ｌ，相对标准偏差为１．６％，加标回收率为９５％～１０６％。本法简便、快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

2,3—二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐，测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０－１５００μｇ／Ｌ相对标准偏差为１．６％，加标回收率为９５％－１０６％。本法简便，快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

碱性氢化物发生—火焰原子吸收光谱法测定锡

对Ｓｎ－ＮａＯＨ－ＫＢＨ４体系进行了系统研究，采用三乙醇胺－ＥＤＴＡ联合干扰抑制剂，可消除一定量铁及合金元素的干扰，对于锡含量小于０．０１％的试样，用苯萃取锡后所有元素不干扰测定。测定液中锡量为０－４μｇ／１０ｍｌ，呈线性关系，灵敏度为０．００４ｍｇ／Ｌ／１％，检出限为０．００８ｍｇ／Ｌ，测定钢中大于０．００１％锡，结果满意。     

荧光法快速分析胶囊中的头孢拉定含量

研究了头孢拉定水溶液的荧光光谱，建立了头孢拉定的快速荧光测定法。荧光强度与头孢拉定含量在１．４ ｍ ｇ／Ｌ～１．４ ｇ／Ｌ的质量浓度范围内呈线性关系。检出限为０．１８ ｍ ｇ／Ｌ。对质量浓度为１．４ ｍ ｇ／Ｌ的头孢拉定标准溶液进行１１ 次平行测定的相对标准偏差为１．３％ 。方法操作简便、快速，用于胶囊中头孢拉定含量的测定。     

氢化物发生电感耦合等离子体原子发射光谱法同时测定水和生物样品中…

研究了一种小型同心氢化物发生配置一个气液分离器后与多道ＩＣＰ－ＡＥＳ联用，同时测定水和生物样品中砷、铋、锑、硒的方法。检出限为砷０．４μｇ／Ｌ，铋０．５μｇ／Ｌ，锑１．４μｇ／Ｌ，硒０．５μｇ／Ｌ，相对标准偏差为砷２．７％，铋１．５％，锑２．７％，硒１．９％。用本法测定美国和国家标准物质中的氢化元素，结果满意。     

Organogermyl,Organostannyl, and Organoplumbyl Phosphines,Arsines, Stibines,and Bismuthines

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.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Structural, magnetic, and spectroscopic studies of YAgSn, TmAgSn, and LuAgSn

The rare earth-silver-stannides YAgSn, TmAgSn, and LuAgSn were synthesized from the elements by arc-melting and subsequent annealing. The three stannides were investigated by X-ray powder and single-crystal diffraction: NdPtSb type, P6₃mc, Z=2, a=468.3(1), pm, wR₂=0.0343, 353 F² values, 12 variables for YAgSn, and ZrNiAl type, P6¯2 m, a=726.4(2), , wR₂=0.0399, 659 F² values, 15 variables for TmAgSn, and a=723.8(2), , wR₂=0.0674, 364 F² values, 15 variables for LuAgSn. Besides conventional laboratory X-ray data with monochromatized Mo radiation, the structures were also refined on the basis of synchrotron data with , in order to clarify the silver-tin ordering more precisely. YAgSn has puckered, two-dimensional [AgSn] networks with Ag-Sn distances of 278 pm, while the [AgSn] networks of TmAgSn and LuAgSn are three-dimensional with Ag-Sn distances of 279 and 284 pm for LuAgSn. Susceptibility measurements indicate Pauli paramagnetism for YAgSn and LuAgSn. TmAgSn is a Curie-Weiss paramagnet with an experimental magnetic moment of 7.2 μ_B/Tm. No magnetic ordering is evident down to 2 K. The local environments of the tin sites in these compounds were characterized by ¹¹⁹Sn Mössbauer spectroscopy and solid-state NMR (in YAgSn and LuAgSn), confirming the tin site multiplicities proposed from the structure solutions and the absence of Sn/Ag site disordering. Mössbauer quadrupolar splittings were found in good agreement with calculated electric field gradients predicted quantum chemically by the WIEN2k code. Furthermore, an excellent correlation was found between experimental ¹¹⁹Sn nuclear magnetic shielding anisotropies (determined via MAS-NMR) and calculated electric field gradients. Electronic structure calculations predict metallic properties with strong Ag-Sn bonds and also significant Ag-Ag bonding in LuAgSn.     

Borinium, borenium, and boronium ions: synthesis, reactivity, and applications

Boron cations are elusive and highly electrophilic species that play a key role in the chemistry of boron. Despite early interest in the chemistry of boron cations, until recently they have largely remained chemical curiosities. However, hints at harnessing their potential as potent electrophiles have begun to appear and developments in weakly coordinating anion technology suggest that this is an area of research that is ripe for exploration. It has been nearly 20 years since the last major review on boron cations; herein we summarize the progress in the area since that time.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Pi bonding and negative hyperconjugation in mono-, di-, and triaminoborane, -alane, -gallane, and -indane

A systematic quantum chemical investigation of mono-, di-, and triaminoborane, -alane, -gallane, and -indane is carried out to determine quantitatively the effects of pi bonding and negative hyperconjugation on structures, energetics, and rotational barriers in these systems. Pi bonding plays a significant role in the aminoborane compounds, but becomes rapidly less significant in the aminoalanes, -gallanes, and -indanes. For each main-group metal X investigated, X-N rotational barriers are found to be essentially equal depending only on the number of remaining in-plane amino groups. The contribution of negative hyperconjugation to reducing rotational barriers, as assessed from natural bond orbital (NBO) delocalization energies, is independent of the pyramidalization of the out-of-plane amino group, and is also dependent only on the number of rotated groups. Optimized tris[bis(trimethylsilyl)amino]-substituted structures of boron, aluminum, gallium, and indium are found to compare quite well with available experimental structural data, and exhibit X-N torsion angles that are independent of the central metal atom.     

Transition-metal-free O-, S-, and N-arylation of alcohols, thiols, amides, amines, and related heterocycles

A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.     

Synthesis of yttrium,lanthanum, neodymium,praseodymium, and lutetium alkoxides and acetylacetonates

A convenient and practical method is proposed for the synthesis of lanthanide and yttrium alkoxides. The method involves dissolving the metals or their hydrides in a solution of dry HCl in the corresponding alcohol, with subsequent dehalogenation of the LnCl₃ solution by an equivalent amount of alkali metal (Na, Li), The rareearth alkoxides are easily converted into acetylacetonates Ln(acac)₃ by the action of acetylacetone.A. N. Nesmeyanov Institute of Elementoorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2490–2493, November, 1992.     

Metal-Directed Formation of Tetra-, Hexa-, Octa-, and Nonanuclear Complexes of Magnesium,Calcium, Manganese,Copper, and Cadmium

Efficacious metal control of self-assembly of dialkylketipinate dianions leads to completely different supramolecular assemblies. The structures of grid 1 , double-decker 2 , triple-decker 3 , and metalla-spherand 4 were characterized by X-ray crystallographic analyses or by NMR spectroscopy.