断续流动注射-催化原子荧光光谱法测定碘

基于碘对亚砷酸-硫酸铈的催化反应，断续流动进样，用氢化物发生．原子荧光光谱法直接测定As(Ⅲ）的浓度变化，建立了微量碘间接测定的方法。在实验条件下，碘离子的线性范围为0．80μg/L；相对标准偏差为2．3％；检测限为4μg/L．加标回收率为92．5％-98．2％。测定结果与硫氰酸铁-亚硝酸催化动力学法相比具有很好的一致性。     

顶空气相色谱法测定血清中微量碘

根据碘离子与硫酸二甲催化反应生成挥发性的碘甲烷，应用顶空ＧＣ法测定血清中的微量碘，回收率为８８．２６％～９５．７２％，相对标准偏差为０．７２％～２．２％。     

高锰酸根褪色光度法测定食盐中的微量碘离子

在稀硫酸介质中，碘离子能快速、定量地还原高锰酸根，在加入碘离子前后，高锰酸钾溶液在波长525nm处的吸光度发生显著变化，且吸光度之差ΔA与加入的碘离子的浓度成正比，确定了最佳反应条件，建立了高锰酸根褪色光度法测定食盐中微量碘离子的新方法。方法的线性范围为0-20μg／mL，线性回归方程为ΔA=0．0165c 0．0041，相关系数r=0．9987，检出限为0．17μg／mL。用于食盐中微量碘离子的测定，加标回收率为91．0％～95．0％．相对标准偏差为0．35％～0．75％。     

［Cu（IO_5OH））_2］~（5－）离子配合物中~（127）I超超精细相互作

用ＥＳＲ方法研究了［Ｃｕ（ＩＯ５ＯＨ）２］５－离子配合物中１２７Ｉ核的超超精细相互作用，旨在证实在碘离子上存在未成对电子自旋和找到一种解释Ｃｕ２＋离子中电子离域的机制。根据ＥＳＲ参数的计算指出碘离子上自旋密度为０．７７％。     

高效阴离子交换色谱-脉冲安培检测器测定多种基体中痕量碘离的方法

建立了高效阴离子交换色谱脉冲安培检测器（HPAEC—PAD）测定碘离子的方法。以62．5mmol／LNaOH溶液作流动相,选用IonPac AS26型强亲水性阴离子交换分析柱,8min可以分离出碘离子,方法的检出限为0．05μg/L（25μL进样,3倍信噪比）,标准曲线的线性范围为0．5—2000μg／L（r=0．9998）。1．0、2．5和25μg/L的碘离子标准溶液各9次进样的相对标准偏差分别为3．8％、2．6％和2．8％。试验了9种常见阴离子、3种易极化阴离子以及3种电化学活性物质对碘离子测定的影响,结果表明,在所选用的色谱条件下上述各化合物均不干扰碘离子的测定。用所建立的方法测定了盐水、矿泉水、海水、芹菜汁和紫菜浸提液等样品中碘离子含量,加标回收率在83％-114％。该方法具有灵敏度高、干扰小和样品前处理简单等优点。     

［Cu（IO5OH）2］^5—离子配合物中^127I超超精细相互作用的…

用ＥＳＲ方法研究了［Ｃｕ（ＩＯ５ＯＨ）２］＾５－离子配合物中＾１２７Ｉ核的超超精细相互作用，旨在证实在碘离子上存在未成对电子自旋和找到一种解释Ｃｕ＾２＋离子中电子离域的机制，根据ＥＳＲ的参数的计算指出碘离子上自旋密度为０．７７％。     

沉淀滴定法测定碘

提出沉淀滴定Ｉ－的新方法，以聚乙烯醇（ＰＶＡ）作为沉淀的胶体保护剂，（Ｉ）－３（碘钅翁离子）作为吸附指示剂，用ＡｇＮＯ３标准溶液直接测定Ｉ－；讨论了滴定机理。检测范围为０．０１～０．１ｍｏｌ／Ｌ，相对误差小于０．２％。本法已用于鸡饲料添加剂中Ｉ－的测定。     

肉苁蓉挥发性化学成分分析

报道了用同时蒸馏—萃取法提取肉苁蓉挥发性物质，测得肉苁蓉挥发油的含量为3．5％；利用GC／MS法分离确认出24种化学成分；用峰面积归一化法得出各化学成分在挥发油中的相对百分含量，其中主要成分为丁香酚，占总挥发油的83．60％；又用单离子法分离出丁香酚，并用IR，EI-MS法对其进行分析确认。     

流动注射催化动力学光度法测定碘的研究

本文采用流动注射技术,利用微量碘离子催化铁的硫氰酸配合物与亚硝酸钠的褪色反应,实现水中微量碘离子的催化动力学光度测定。该法测定碘离子的线性范围是1．0～7．0μg／mL,检出限为0．5μg／mL,相对标准偏差为5．0％。方法用于实际水样中微量碘离子的测定,结果令人满意。     

哈尔滨市平房区碘缺乏病的自我考评结果分析

对哈尔滨市平房区7～10岁学龄儿童尿碘、甲状腺肿及用户碘盐进行调查，其结果为：尿碘中位数为315μg／L，＜50μg／L者占5．7％，＜100μg／L者占10．6％；甲状腺肿大率为21．80％；盐碘中位数为46．4×10-6，＜20×10－6者占3．9％，按照WHO、UNICEF、ICCIDD三个国际组织提供的考核评估标准，尿碘、盐碘水平已达标，但甲状腺肿大率未达标。     

全氟及α,α-二氯多氟烷基亚磺酸盐的反应

全氟烷基亚磺酸钠与溴水反应,得到全氟烷基磺酰溴(RfSO2Br),(但在乙腈,乙酸等有机溶剂中与溴反应,则生成溴代全氟烷.在碘化钾水溶液中,全氟烷基亚磺酸钠与碘反应,生成碘代全氟烷.α,α-二氯多币烷基亚磺酸钠在类似条件下与溴水反应,生成1-溴-1,1-二氯多氟烷,与碘在磺化钾水溶液中反应,生成1-碘-1,1-二氯多氟烷.1-溴-1,1-二氯多烷及1-碘-1,1-二氯多氟烷易对烯键加成,也可与连二亚硫酸钠在温和条件下发生亚磺化脱溴及脱碘反应.α,α-二氯二氟乙基亚磺酸钠在强酸中比较稳定,与强碱,氧化剂或还原剂发生反应,得到相应的产物.     

带功能基的全氟(烷基乙烯基)醚的研究 II: 全氟(5-甲基-4,7-二氧杂-Δ^8-壬酸)甲酯的合成

本文报道全氟4-甲基-3,6-二氧杂-Δ^7-辛基亚磺酸钠的制备及其反应, 并应用于合成标题化合物。     

Pentaiodide komplexer Alkalimetall‐Kronenether‐Kationen: Darstellung und strukturelle Charakterisierung der Verbindungen [M(Benzo‐15‐Krone‐5)2]I5 mit M = Na,K, Rb,Cs

Pentaiodides of Complex Alkaline Metal Crown Ether Cations: Synthesis and Structural Characterisation of the Compounds [M(benzo‐15‐crown‐5)₂]I₅, M = Na, K, Rb and Cs The isotypic compounds [M(benzo‐15‐crown‐5)₂]I₅, M = Na, K, Rb and Cs are obtained as single crystals via the reaction of benzo‐15‐crown‐5, MI and iodine (2 : 1 : 2) from ethanol/dichloromethane (1 : 1). These compounds crystallize in the monoclinic space group P2₁/n with four formula units in the unit cell. The cations form typical sandwich complexes. The volume of the unit cell increases by 4, 3 % from the sodium to the caesium compound, corresponding to the increasing space required by the cations. The pentaiodide units consist of a elongated triiodide unit and two iodine half‐molecules. These iodine molecules are completed by centres of symmetry. The interconnection between the pentaiodide units leads to the formation of zig‐zag chains that run along [001]. Considering the strongly different ionic radii of the alkali‐metal cations, the existence of this number of isotypic structures is rather surprising.     

气相色谱法测定婴幼儿配方谷粉中的碘

建立婴幼儿配方谷粉中碘的气相色谱定量分析方法。样品经α-淀粉酶水解,利用乙酸锌和亚铁氰化钾作为沉淀剂将样品中的蛋白质除去,在硫酸环境中把碘离子氧化成碘,碘与丁酮反应生成3-碘代-2-丁酮,用正己烷萃取,气相色谱法定量检测。碘的含量在0.04~0.48μg/m L范围内与色谱峰面积呈现良好的线性关系,线性相关系数r=0.998 2,方法的检出限为90μg/kg。测定结果的相对标准偏差为3.49%(n=6),样品加标回收率为86.2%~95.6%。该方法具有较高灵敏度和准确度,适用于婴幼儿配方谷粉中碘含量的检测。     

Base-controlled selective conversion of Michael adducts of malonates with enones in the presence of iodine

An efficient base-controlled selective conversion of the Michael adducts of malonates with enones in the presence of iodine is reported. Highly functionalized cyclopropane, oxetane, and α-hydroxylmalonate derivatives are obtained selectively using DBU, Na(2)CO(3), and NaOAc as the base, respectively. O(2) was identified to be crucial to the formation of oxetane and α-hydroxylmalonate derivatives.     

Epithermal instrumental neutron activation analysis in conjunction with anti-coincidence gamma-ray spectrometry for investigating iodine levels in Canadian foods

In order to reduce interferences from high activities of ²⁴Na, ⁵⁶Mn, ⁸²Br, and ³⁸Cl as well as to improve detection limits, precision, and accuracy of measuring iodine levels in biological materials, foods and diets in particular, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence (EINAA-AC) gamma-ray spectrometry was employed. The Compton scattering background in the region of the 442.9-keV photopeak of ¹²⁸I was significantly suppressed by anti-coincidence counting. In order to validate the EINAA-AC method as well as to evaluate its broad applicability to diverse types of biological material, 17 NIST and IAEA reference materials containing very low to high levels of iodine as well as interfering elements were analyzed by the EINAA-AC method. The samples were irradiated in the cadmium-lined pneumatic site at a neutron flux of 2 × 10¹¹ cm^?2 s^?1 of the Dalhousie University SLOWPOKE-2 Reactor (DUSR) facility for 10 or 20 min followed by 1-min decay and 30-min counting. The detection limit for iodine by EINAA-AC was improved by a factor of 2–5 compared to EINAA depending on the sample matrix and other factors, and a limit of 3–5 μg kg^?1 was achieved for low-salt foods. We found the RSD to be about ±5 % above 200, increasing to ±10 % at 20, and then to greater than ±30 % at about 5 μg kg^?1 iodine levels.     

Efficient oxidizing methods for the synthesis of oxandrolone intermediates

Mild, efficient and eco-friendly oxidation of 17alpha-methylandrostan-3beta-17beta-diol (1) has been studied with three different reagents viz. pentavalent iodine reagent 2-iodoxy benzoic acid (IBX) in DMSO at 65 degrees C, sodium hypochlorite and H2O2/Na2WO4 under phase transfer conditions to give 17beta-hydroxy-17alpha-methylandrostan-3-one (mestanolone 2), a drug intermediate as oxidized product. The H2O2/Na2WO4/PTC gave mestanolone in high yield and purity whereas sodium hypochlorite/PTC system yielded some chlorinated material along with the mestanolone. However, 1 with 2.5 equivalent of IBX gave 17beta-hydroxy-17alpha-methyl-Delta1-androsten-3-one (3) under the similar reaction conditions in good yield and single step reaction.     

Experimental and Theoretical Investigations of Structural Isomers of Dichalcogenoimidodiphosphinate Dimers: Dichalcogenides or Spirocyclic Contact Ion Pairs?

A synthetic protocol for the tert-butyl-substituted dichalcogenoimidodiphosphinates [Na(tmeda){(EPtBu(2))(2)N}] (3 a, E=S; 3 b, E=Se; 3 c, E=Te) has been developed. The one-electron oxidation of the sodium complexes [Na(tmeda){(EPR(2))(2)N}] with iodine produces a series of neutral dimers (EPR(2)NPR(2)E--)(2) (4 b, E=Se, R=iPr; 4 c, E=Te, R=iPr; 5 a, E=S, R=tBu; 5 b, E=Se, R=tBu; 5 c, E=Te, R=tBu). Attempts to prepare 4 a (E=S, R=iPr) in a similar manner produced a mixture including HN(SPiPr(2)). Compounds 4 b, 4 c and 5 a-c were characterised by multinuclear NMR spectra and by X-ray crystallography, which revealed two alternative structures for these dimeric molecules. The derivatives 4 b, 4 c, 5 a and 5 b exhibit acyclic structures with a central chalcogen-chalcogen linkage that is elongated by approximately 2 % (E=S), 6 % (E=Se) and 8 % (E=Te) compared to typical single-bond values. By contrast, 5 c adopts an unique spirocyclic contact ion-pair structure in which a [(TePtBu(2))(2)N](-) ion is Te,Te' chelated to an incipient [(TePtBu(2))(2)N](+) cyclic ion. DFT calculations of the relative energies of the two structural isomers indicate a trend towards increasing stability for the contact ion pair relative to the corresponding dichalcogenide on going from S to Se to Te for both the isopropyl and tert-butyl series. The two-electron oxidation of [Na(tmeda){(EPtBu(2))(2)N}] (E=S, Se, Te) with iodine produced the salts [(EPtBu(2))(2)N](+)X(-) (7 a, E=S, X=I(3); 7 b, E=Se, X=I; 7 c, E=Te, X=I), which were characterised by X-ray crystallography. Compound 7 a exists as a monomeric, ion-separated complex with [d(S--S)=2.084(2) A]; 7 b and 7 c are dimeric [d(Se--Se)=2.502(1) A; d(Te--Te)=2.884(1) A].     

火焰原子吸收法测定植物样品中硼与碘

将ＢＯ＾３－３转化为ＢＦ＾－４，ＩＯ＾－３转化为Ｉ＾－以Ｃｄ（ｐｈｅｎ）＾２＋３络合和硝基苯萃取，用火焰原子吸收法间接测定与碘，其特征浓度达０．０１６μｇ／ｍＬ１％Ａ和０．０２８μｇ／ｍＬ１％Ａ，在稻米等样品中作加标回收，硼回收率为９２．８－１０２．４％，碘为９７．２－１０６．７％。