学龄前儿童血铅,发铅含量及其与生长发育的关系

实验选择重庆市城区相同年龄段（６～７岁）学龄前儿童２４０名，男，女各半，观察儿童血铅，发铅含量及其与生长发育的关系，结果显示：生活在重庆闹市区的学龄前儿童受到铅污染相当严重，以推荐的０．４８３μｍｏｌ／Ｌ为全血铅接受上限值，则春季有５０．９％（平均０．４８３μｍｏｌ／Ｌ）儿童，秋季有高达８１．６６％（平均为０．６５０μｍｏｌ／Ｌ）儿童血铅浓度超过标准，发铅的测定显示相似结果。本实验还发现重庆春，秋     

宁波市江东区1～6岁儿童血铅水平调查

随机抽取了宁波江东区１ ～６ 岁的散居儿童和集居儿童１０７０ 名, 其中男５４９ 名, 女５２１名, 于１９９９ 年１ 月至６ 月进行了静脉血铅测定。结果显示, 江东区１ ～６ 岁儿童血铅为０－４８８ ±０－１０６ μｍｏｌ／Ｌ, 儿童血铅浓度≥０－４８３ μｍｏｌ／Ｌ 者, 占总调查人数的４７－１ ％ 。不同年龄的血铅水平及不同性别的血铅水平虽略有差异, 但经统计学分析, 无显著差异。从血铅水平的等级分布分析, 血铅水平在１００ ～１４９－９ μｇ／Ｌ 者, 占９３－８ ％ , 血铅水平在１５０ ～１９９－９ ％ μｇ／Ｌ 者, 占６－１ ％ 。通过血铅检测, 对早期发现的高血铅儿童进行及时的个体干预是非常重要的, 也是预防儿童铅中毒的重要途径。     

顺德杏坛地区儿童血铅水平调查分析

用电感耦合等离子体质谱仪测定了顺德杏坛地区城乡间共600名0～6岁儿童的血铅含量,并对血铅水平及高血铅率进行了统计分析。结果表明,受测儿童的平均血铅水平为68．79μg／L,高血铅率为13．33％。城乡间儿童血铅水平和高血铅率均存在显著差异,城镇儿童血铅水平为79．19μg／L,高血铅率为16．67％;农村儿童血铅水平为58．38μg／L,高血铅率为10．00％。同一地区不同性别间的血铅水平和高血铅率则无显著差异。     

脐血中铅,锌水平与新生儿发育的关系

为研究脐血中铅，锌水平对新生儿发育是否有不良影响，以１３１例新生儿为调查对象，用新生儿２０项行为神经评分检测新生儿神经行为发育，以石墨炉原子吸收光谱法和火焰原子吸收分光光度法分别测定脐血中铅，锌的含量，结果表明，脐血铅与新生儿神经行为为总得分及主动肌张力呈负相关，差异有显著意义，脐血铅≥０．２９μｍｏｌ／Ｌ的新生儿其神经行为发育明显落后于血铅〈０．１４μｍｏｌ／Ｌ者，差异有显著意义，表明血铅水平低     

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。     

茚三酮缩7—氨基—8—羟基喹啉—5—磺酸催化荧光测定痕量钒（Ⅴ）及其…

合成了新型席夫碱类试剂茚三酮缩７－氨基－８－羟基喹啉－５－磺酸，建立了该剂催化荧光测定痕量钒的 新体系，反应在盐酸体系中进行，其λｅｘ／λｅｍ为３２５／４４８（ｎｍ），钒（Ⅴ）的量在０－４０．０μｇ／Ｌ、４０．０－１６０．０μｇ／Ｌ呈良好线性关系，检测下限为１．７μｇ／Ｌ，方法用于水样痕量钒的测定，结果令人 满意。     

在线流动注射螯合树脂预富集石英缝管增敏火焰原子吸收法测定水中痕量铅

应用高效的在线流动注射螯合树脂预富集石英缝管增敏火焰原子吸收系统直接测定水呈痕量铅。实验用内装２００ｍｇＡｍｂｅｒｌｉｔｅＸＡＤ－４键合的５－磺酸－８羟基喹啉螯合树脂的锥形柱,在ＰＨ９条件下样品流速为８．０ｍＬ／ｍｉｎ,９０ｓ采样,用０．５ｍｏｌ／Ｌ Ｈｃｌ洗脱,在分析速度为３０样／ｈ,获得３６倍的富集,经石英缝管增敏,灵敏度提高达１１５倍,线性范围为０－２００μｇ／Ｌ,检出限为１μｇ／Ｌ。铅含量水平５０μｇ／Ｌ的水样连续测定１１次的相对标准偏差２．５％,可直接测定水体中μｇ／Ｌ级的铅。     

钒（Ⅳ）—硫胺素荧光光度法的研究与应用

利用钒（Ⅳ）作为氧化剂将硫胺素氧化成硫胺荧,建立了一种测量痕量硫胺素的荧光分光光度法,并将该方法应用于药物中硫胺素的测定。该方法测定硫胺素的线性范围为０．８～２４０．０μｇ／Ｌ;检出限为０．４５μｇ／Ｌ;对于４０．０μｇ／Ｌ的硫胺素测定１０次,其相对标准偏差为１．５％。     

高效液相色谱法同时测定血清中肌酸、尿酸和肌酐

报道了快速、简便同时测定血清中肌酸，尿酸和肌酐的ＨＰＬＣ法．以０．０２ｍｏｌ／ＬＫＨ２ＰＯ４（ｐＨ６．５）为流动相，三种物质可在２ｍｉｎ内分离，检出限分别为：肌酸０．６９μｇ／ｍＬ，尿酸０．２１μｇ／ｍＬ，肌酐０．１０μｇ／ｍＬ．     

水杨基荧光酮—过氧化氢催化动力学光度法测定痕量锇（Ⅳ）

在碱性介质中，痕量锇（Ⅳ）对水杨基荧光酮（ＳＡＦ）与过氧化氢的氧化还原反应有显著的催化作用。本文以此为基础，提出用分光光度催化动力学测定痕量锇（Ⅳ）的新方法。本法未加掩蔽剂时的线性范围是０．０８－０．８０μｇ／Ｌ，加入掩蔽剂后的线性范围是０．０８－０．８０μｇ／Ｌ，检出限为０．０８μｇ／Ｌ。本法用于实际样品中Ｏｓ（Ⅳ）的测定，结果良好，本实验还测定了此催伦反应的活化能和反应级数。     

5,10,15,20-四{对[3,5-二-(烷氧基)苯甲酰胺基]苯基}卟啉及其锌配合物的合成表征

设计合成了5种未见文献报道的5,10,15,20-四{对[3,5-二-(烷氧基)苯甲酰胺基]苯基}卟啉及其锌金属配合物,并用IR,UV-Vis,1H NMR,元素分析以及XPS对其组成和结构进行了表征,研究了这10种酰胺基系列卟啉化合物的拉曼光谱和荧光光谱的变化.结果显示链长对荧光和拉曼光谱没有明显影响,其取代基效应基本相同,配体的荧光强度强于锌配合物的荧光强度.在拉曼光谱中,由于卟啉分子平面的对称性由D2h变为D4h群及其锌离子d轨道的电子效应,卟啉配体和锌配合物之间的拉曼光谱有很大差别.     

光谱法研究硝基苯基卟啉锌与咪唑类的轴向配位反应

采用紫外-可见光谱滴定法和荧光光谱法,考察了5-对硝基苯基-10,15,20-三苯基锌卟啉和5-邻硝基苯基-10,15,20-三苯基锌卟啉与3种咪唑类客体小分子进行轴向配位反应的光谱性质,并探讨取代基团在不同位置时的锌卟啉及具有不同结构特点的客体对该类轴配反应进行的影响。 实验结果表明,2种锌卟啉与咪唑类客体之间的轴配反应是按摩尔比1∶1进行,轴配反应的平衡常数均按K(2-MeIm)＞K(N-MeIm)＞K(Im)顺序依次减弱,其中5-邻硝基苯基-10,15,20-三苯基锌卟啉与2-甲基咪唑间的轴配反应有最大的平衡常数5.85×10⁵ L/mol。 轴配反应的平衡常数均随温度的升高而降低,温度升高不利于平衡反应的进行。 热力学参数表明,这类反应的驱动力是焓驱动,是自发进行的配位反应。 随客体浓度的增加,5-对硝基苯基-10,15,20-三苯基锌卟啉(荧光峰位：592.9、634.2 nm)与咪唑类客体的轴配体系具有荧光增强的效应,5-邻硝基苯基-10,15,20-三苯基锌卟啉(荧光峰位：583.6、629.8 nm)与咪唑类客体的轴配体系具有荧光猝灭的效应。 轴配体系的荧光效应是由锌卟啉中硝基基团的位置所决定的,而与客体的结构特点无关。     

Synthesis of meso-5-azaindolyl-appended Zn(II) porphyrins via Pd-catalyzed annulation

Pd-catalyzed annulation reaction of meso-hexynyl Zn(II) porphyrin with 4-amino-3-iodopyridine efficiently provides meso-3-(5-azaindolyl)-substituted Zn(II) porphyrin as a major product, which assembles to form a slipped cofacial dimer by the complementary coordination of the pyridine moiety to the Zn(II) center. 2-iodoaniline and 2-iodophenol also undergo this [3 + 2] annulation with the meso-hexynyl Zn(II) porphyrin to furnish meso-indolyl- and benzofuranyl-substituted Zn(II) porphyrins, respectively.     

新型β,β-桥连双卟啉的合成及其光敏活性研究

以1,6-二溴己烷为桥连试剂, 2-(1-羟基萘基)-5,10,15,20-四苯基卟啉及其Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ)配合物为原料, 合成了4个新型β,β-桥连双卟啉. 以1,3-二苯基异苯并呋喃(DPBF)为猝灭剂, 测试了双卟啉及其Ni(Ⅱ), Zn(Ⅱ)配合物在光照条件下产生单线态氧的能力, 并研究了4个双卟啉化合物在光照和无光照条件下对pBR322质粒DNA的切割能力(用凝胶电泳)和对金黄色葡萄球菌(ATCC 25923)的光敏抑菌活性. 结果表明, 新型双卟啉光敏剂具有较好光敏活性, 产生的活性氧能有效杀灭金黄色葡萄球菌.     

Recognition through self-assembly. A quadruply-hydrogen-bonded, strapped porphyrin cleft that binds dipyridyl molecules and a [2]rotaxane

Quadruply-hydrogen-bonded porphyrin homodimer Zn1.Zn1 has been designed, assembled, and evaluated as a supramolecular cleft-featured receptor for its ability to bind dipyridyl guests in chloroform-d. Monomer Zn1 consists of a 2-ureidopyrimidin-4(1H)-one unit, which was initially reported by Meijer et al., and a zinc porphyrin unit. The zinc porphyrin is strapped with an additional aliphatic chain for controlling the atropisomerization of porphyrin. The 2-ureidopyrimidin-4(1H)-one unit dimerizes exclusively in chloroform even at the dilute concentration of 10(-)(4) M, while the two "strapped" zinc porphyrin units of the homodimer provide additional binding sites for selective guest recognition. (1)H NMR studies indicate that the new homodimer Zn1.Zn1 adopts an S-type conformation due to strong donor-acceptor interaction between the electron-rich porphyrin units and the electron-deficient 2-ureidopyrimidin-4(1H)-one unit. (1)H NMR, UV-vis, and vapor pressure osmometry investigations reveal that Zn1.Zn1 could function as a new generation of assembled supramolecular cleft, to be able to not only efficiently bind linear dipyridyl molecules 14-17, resulting in the formation of stable termolecular complexes, with K(aasoc) values ranging from 3.8 x 10(6) to 8.9 x 10(7) M(-)(1), but also strongly complex a hydrogen-bond-assembled [2]rotaxane, 18, which consists of a rigid fumaramide thread and a pyridine-incorporated tetraamide cyclophane, with K(aasoc) = 1.2 x 10(4) M(-)(1). (1)H NMR competition experiments reveal that complexation to the dipyriyl guests also promotes the stability of the quadruply-hydrogen-bonded dimeric receptor.     

Synthesis of non-covalent BODIPY–metalloporphyrin dyads and triads

Boron-dipyrromethenes (BODIPY) containing oxypyridine substituents at 3- and 3,5-positions and metalloporphyrins (Zn(II), Ru(II)) were used to synthesize four non-covalent BODIPY–metalloporphyrin dyads and four BODIPY–metalloporphyrin triads assembled using metal–pyridine ‘N’ interaction. The formation of BODIPY–metalloporphyrin assemblies was confirmed by 1D and 2D NMR methods and X-ray crystal structure obtained for one of the BODIPY–metalloporphyrin dyad. In ¹H NMR, the signals of oxypyridine group(s) of BODIPY unit showed significant upfield shifts supporting the coordination of oxypyridine group of BODIPY unit to metalloporphyrin unit. The NMR study also indicated that Zn(II) porphyrin forms relatively weak BODIPY–Zn(II) porphyrin conjugates, whereas Ru(II) porphyrin forms strong BODIPY–Ru(II) porphyrin conjugates. The X-ray structure solved for BODIPY–Zn(II)porphyrin dyad revealed that the Zn(II) porphyrin coordinated to the BODIPY unit obliquely and the angle between the Zn(II) porphyrin and the pyridyl ring is 70°. The absorption properties of stable BODIPY–Ru(II) porphyrin conjugates showed the overlapping absorption features of both the components and the fluorescence studies indicated that the BODIPY unit emission was significantly quenched on coordination with RuTPP(CO) unit. The electrochemical studies exhibited the features of both BODIPY and metalloporphyrin units in dyads and traids.     

Tetrachelate porphyrin chromophores for metal oxide semiconductor sensitization: effect of the spacer length and anchoring group position

Four Zn(II)-tetra(carboxyphenyl)porphyrins in solution and bound to metal oxide (TiO2, ZnO, and ZrO2) nanoparticle films were studied to determine the effect of the spacer length and anchoring group position (para or meta) on their binding geometry and photoelectrochemical and photophysical properties. The properties of three types of anchoring groups (COOH and COONHEt3) for four Zn(II)-porphyrins (Zn(II)-5,10,15,20-tetra(4-carboxyphenyl)porphyrin (p-ZnTCPP), Zn(II)-5,10,15,20-tetra(3-carboxyphenyl)porphyrin (m-ZnTCPP), Zn(II)-5,10,15,20-tetra(3-(4-carboxyphenyl)phenyl)porphyrin (m-ZnTCP2P), and Zn(II)-5,10,15,20-tetra(3-ethynyl(4-carboxyphenyl)phenyl)porphyrin (m-ZnTC(PEP)P)) were compared. In m-ZnTCPP, m-ZnTCP2P, and m-ZnTC(PEP)P the four anchoring groups are in the meta position on the meso-phenyl rings of the porphyrin macrocycle, thus favoring a planar binding mode to the metal oxide surfaces. The three meta-substituted porphyrin salts have rigid spacer units of increasing length (phenyl (P), biphenyl (P2), and diphenylethynyl (PEP)) between the porphyrin ring and the carboxy anchoring groups, thus raising the macrocycle from the metal oxide surface. All porphyrins studied here, when bound to TiO2 and ZnO, exhibited quenching of the fluorescence emission, consistent with electron injection into the conduction band of the semiconductor. Steady-state UV-vis and fluorescence studies of p-ZnTCPP on insulating ZrO2 showed evidence of aggregation and exciton coupling. This was not observed in any of the meta-substituted porphyrins. The photoelectrochemical properties (IPCE, Voc, and Isc) of the porphyrins bound to TiO2 films in solar cells have been measured and rationalized with respect to the sensitizer binding geometry and distance from the surface.     

Water-soluble supramolecular porphyrin dimer: self-organization of mono(imidazolyl)-substituted Zn porphyrin to a special-pair type dimer in water

Tris(4-carboxylphenyl)-mono(N-methylimidazolyl)-substituted Zn porphyrin was synthesized as a precursor for a water-soluble supramolecular porphyrin dimer. The dimer formation was performed in a NaHCO₃ aq solution (pH 8.4) and phosphate buffer solutions (pH 7.4-9.0). The split Soret bands of Zn porphyrin observed in the absorption spectra clearly showed self-organization to a special-pair type slipped cofacial dimer via metal coordination of imidazole even in water.     

Effects of multiple pathways on excited-state energy flow in self-assembled wheel-and-spoke light-harvesting architectures

Static and time-resolved optical measurements are reported for three cyclic hexameric porphyrin arrays and their self-assembled complexes with guest chromophores. The hexameric hosts contain zinc porphyrins and 0, 1, or 2 free base (Fb) porphyrins (denoted Zn(6), Zn(5)Fb, or Zn(4)Fb(2), respectively). The guest is a core-modified (O replacing one of the four N atoms) dipyridyl-substituted Fb porphyrin (DPFbO) that coordinates to zinc porphyrins of a host via pyridyl-zinc dative bonding. Each architecture is designed to have a gradient of excited-state energies for excitation funneling among the weakly coupled constituents of the host to the guest. Energy transfer to the lowest-energy chromophore(s) (coordinated zinc porphyrins or Fb porphyrins) within a hexameric host occurs primarily via a through-bond (TB) mechanism, is rapid ( approximately 40 ps), and is essentially quantitative (>or=98%). Energy transfer from a pyridyl-coordinated zinc porphyrin of the host to the guest in the Zn(6)*DPFbO complex has a yield of approximately 75%, a rate constant of approximately (0.7 ns)(-1), and significant F?rster through-space (TS) character. In the case of Zn(5)Fb*DPFbO, which has an additional TS route via the Fb porphyrin with a rate constant of approximately (20 ns)(-1), the yield of energy transfer to the guest is somewhat lower ( approximately 50%) than that for Zn(6)*DPFbO. Complex Zn(4)Fb(2)*DPFbO has an identical TS pathway via the Fb porphyrin plus an additional TS pathway involving the second Fb porphyrin (closer to the guest) with a rate constant of approximately (0.5 ns)(-1). This complex exhibits an energy-transfer yield to the guest that is significantly enhanced over that for Zn(5)Fb*DPFbO and comparable to that for Zn(6)*DPFbO. Collectively, the results for the various arrays suggest designs for similar host-guest complexes that are expected to exhibit much more efficient light harvesting and excitation trapping at the central guest chromophore.     

Synthesis of cyclic hexameric porphyrin arrays. Anchors for surface immobilization and columnar self-assembly

To investigate new architectures for the self-assembly of multiporphyrin arrays, a one-flask synthesis of a shape-persistent cyclic hexameric array of porphyrins was exploited to prepare six derivatives bearing diverse pendant groups. The new arrays contain 6-12 carboxylic acid groups, 12 amidino groups, 6 thiol groups, or 6 thiol groups and 6 carboxylic acid groups in protected form (S-acetylthio, TMS-ethyl, TMS-ethoxycarbonyl). The arrays contain alternating Zn and free base (Fb) porphyrins or all Zn porphyrins. The one-flask synthesis entails a template-directed, Pd-mediated coupling of a p/p'-substituted diethynyl Zn porphyrin and a m/m'-substituted diiodo Fb porphyrin. The porphyrin building blocks (trans-A(2)B(2), trans-AB(2)C) contain the protected pendant groups at nonlinking meso positions. A self-assembled monolayer (SAM) of a Zn(3)Fb(3) cyclic hexamer containing one thiol group on each porphyrin was prepared on a gold electrode and the surface-immobilized architecture was examined electrochemically. Together, the work reported herein provides cyclic hexameric porphyrin arrays for studies of self-assembly in solution or on surfaces.