CWS1.0色谱工作站测定微量发硒

利用硒与４－硝基邻苯二胺在硫酸和高氯酸溶液中生成５－硝基－２，１，３－苯并硒二唑，且可被萃取至甲苯中的性质，用气相色谱法配合电子捕获检测器测定了甲苯中的５－硝基－２，１，３－苯并硒二唑，从而测定了硒的含量，数据处理采用自行研制的ＣＷＳ１．０色谱工作站进行，可对样品采集文件进行多种处理，操作快速，简便，处理结果精密，准确，该法用于人发中微量硒的含量测定，获得了满意的结果。     

硒对氟中毒大鼠尿氟及脑肾组织脂质过氧化物含量的影响

大鼠饲料分别加入２×１０－６、４×１０－６硒．饮用７．５×１０－６、１５×１０－６氟水．１个月后，随尿硒粪硒排量增加，尿氟排量也增高，以２×１０－６硒饲料排氟效果最佳．血浆中ＡＬＰ、ＧＯＴ、ＧＰＴ及ＬＤＨ等酶活性加硒组有不同程度的降低．随后两次增高氟水量重复试验，给以２×１０－６硒饲料，仍观察到尿氟排量增高．血中含硒酶谷胱甘肽过氧化物酶活性也有升高趋势，脑及肾中脂质过氧化物（ＬＰＯ）含量明显减少，病区患者服硒后，尿氟含量亦高于对照组．实验结果提示；１）硒能促使体内氟由尿中排出；２）降低某些组织ＬＰＯ含量；３）减少体内氟含量；４）预防和改善氟中毒某些临床症状。     

利用微波消解和高效液相色谱荧光检测法测定环境水样中痕量硒

基于微波消解和正相液相色谱－荧光检测测硒法,实现了对环境水样中亚纳克级硒的测定。考察了ＨＮＯ３和Ｈ２ＳＯ４－Ｈ２Ｏ２两种消化体系及其工作条件,方法检出限分别可达 ７．２和 １０．４ ｐｇ Ｓｅ,对标准参考物质的回收率分别为９９．４±２．０和９７．８±２．５％,在０～１．５ｎｇＳｅ范围内有线性关系（Ｒ２＜０．９９６）。对北京地区 ４种不同类型水体水样含硒量进行了分析测定（２ｍＬ样品）,其浓度范围为 ０．２０～０．９０μｇ／Ｌ,标准加入回收率为９９．１％～１０３．４％。     

荧光法测定水样中的硒(Ⅳ)、硒(Ⅵ)和有机硒

本文提出了水样中硒（Ⅳ）、硒（Ⅵ）和有机硒的荧光测定方法。基于酸性介质中２,３－二氨基萘与硒（Ⅳ）的选择性反应,直接测定硒（Ⅳ）;利用盐酸还原硒（Ⅵ）和ＨＮＯ３－ＨＣｌＯ４消化有机硒后,用差减法分别测出硒（Ⅵ）和有机硒。检出限０．０７μｇ／Ｌ,线性范围０～１０μｇ／Ｌ。硒（Ⅳ）、硒（Ⅵ）和有机硒的相对标准偏差与回收率分别为２．４％和９８．５％～１０１．５％、３．１％和９４．８％～１０３％、４．０％和９４．５％～９８．８％。     

反式-2-(4-[2-(4-取代苯基)乙烯基]苯基)-5-(4-联苯基)唑的合成、电子光谱与光性能

通过４－ＲＣ６Ｈ４ＣＨＯ与２－（４－甲基苯基）－５－（４－联苯基）口恶唑（Ｒ＝Ｈ，Ｍｅ，Ｅｔ，ｉ－Ｐｒ，ｉ－Ｂｕ，Ｐｈ，ＯＭｅ，Ｆ，Ｃｌ，Ｂｒ）在碱催化下的缩合反应合成了１０个新的反式－２－｛４－［２－（４－取代苯基）乙烯基］苯基｝－５－（４－联苯基）口恶唑类化合物，经元素分析、ＩＲ、ＵＶ及ＭＳ确定了它们的结构．并测定了荧光发射光谱、荧光量子产率和激光转换效率．     

荧光分光光度法测定兽药中诺氟沙星

本文报道在ｐＨ２．６和β－环糊精存在下荧光分光光度法测定诺氟沙星，β－环糊精增强诺氟沙星荧光强度约２倍。其线性范围为７．８×１０－４μｇ／ｍＬ—１．５μｇ／ｍＬ，检测限为７．８×１０－４μｇ／ｍＬ，相对标准偏差为２．５％（ｎ＝５），方法用于兽药中诺氟沙星的测定，结果令人满意。     

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。     

9-(3，5-二溴)水杨基荧光酮-溴化十六烷基三甲铵荧光光度法测定微量铝

研究了９－（３,５－二溴）水杨基荧光酮与铝（Ⅲ）的反应条件。在ＰＨ５．５的（ＣＨ２）６Ｎ４－ＨＣＬ缓冲溶液中,ＡＩ（Ⅲ）与试睡成络合物使试剂的荧光猝灭。建立了铝－９－（３,５－二溴）,水杨基荧光酮体系测定痕量铝的荧光光度法。荧光强度与铝的含量在０～１．４μｇ／ｍＬ范围内呈线性关系。本法已用于合金风标样中铝的测定。     

新荧光试剂—3—邻甲苯基—5—（2‘—羧基苯偶氮）绕丹宁的荧光性质研究

本文报道新荧光试剂－３－邻甲苯基－５－（２’－羧基苯偶氮）绕丹宁（３ＯＭＲＡＣＰ）的荧光特性，建立了荧光分析测定铜的方法，在ｐＨ５．６时，３ＯＭＲＡＣＰ与铜（Ⅱ）形成螯合物，并在λｅｘ／λｅｍ＝３０８ｎｍ／４０５ｎｍ产生强烈荧光，其荧光强度与铜（Ⅱ）的浓度在０．１～４．０×１０＾－２μｇ／ｇ范围内呈线性关系，检测限达５×１０＾－４μｇ／ｇ。测定了人发中的痕量铜，结果满意。     

2,4—二甲氧基苯基荧光酮荧光熄灭法测定痕量钨

１引言荧光光度法测定钨所用的荧光酮类试剂有：二溴羟基苯基荧光酮、５’－硝基水杨基荧光酮、水杨基荧光酮等．２，４－二甲氧基苯基荧光酮（ＤＭＰＦ）自合成以来，已应用于荧光熄灭法测定钛、铁等．作者详细地研究了在混合表面活性剂（ＣＴＭＡＢ＋ＯＰ－１０）协同增敏作用下，钨与２，４－二甲氧基苯基荧光酮的荧光熄灭体系．该法显色迅速，荧光强度稳定，线性范围宽．在混合掩蔽剂ＥＤＴＡ和盐酸羟胺存在下，测定合金钢中的钨，结果满意。２实验部分２．对主要仪器与试剂９３０型荧光光度计；钨标准溶液（ｌ．００ｍｇ／Ｌ）；２，４…     

Observation in the Growth of Selenium Nanoparticles

A mild chemical reduction method was developed to synthesize selenium nanoparticles. The observation of the particle growth within a five‐minute time frame at an elevated temperature is achieved, and it was evidenced by analyzing the particle sizes from electron micrographs. The samples at individual growth stages were taken after the reaction was quenched by cooling to stop further particle growth. The nucleation and growth processes dominate different reaction time regimes under the experimental condition. We demonstrate the size evolution of the selenium nanoparticles from 30 nm to about 200 nm.     

Specific determination of selenoaminoacids in whole milk by 2D size-exclusion-ion-paring reversed phase high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP MS)

A procedure was developed for the quantitative recovery of selenomethionine (SeMet) and selenocysteine (SeCys) from whole milk. It was based on the protein unfolding, carbamidomethylation of the aminoacid residues using iodoacetamide and proteolysis using Protease XIV. The selenoaminoacids were specifically determined by ion-paring reversed phase HPLC-ICP MS after their isolation from the post-reaction mixture by size-exclusion LC. Se(IV) present in the sample was derivatized as well and was determined along with the selenoaminoacids. The origin and identity of species were identified by the co-elution with the Se(IV), isotopically labelled selenomethionine, and with the synthetic standard of carbamidomethylated selenocysteine. The method development for SeCys was assisted by using glutathione peroxidise as the SeCys standard. SeMet, SeCys and Se(IV) were quantified by the method of standard additions. The mass balance provided a measure of the method validation. The method was applied to monitoring selenium speciation during supplementation of cows (dose-effect study) with Se-rich yeast containing feed and during milk processing.     

Die Reaktion von SePh2 mit N‐Chlorsuccinimid. Kristallstrukturen von [SeCl2Ph2] und [SeCl2Ph2(Succinimid)2]

Reaction of SePh₂ with N‐Chlorosuccinimide. Crystal Structures of [SeCl₂Ph₂] and [SeCl₂Ph₂(succinimide)₂] SePh₂ reacts with N‐chlorosuccinimide in acetonitrile solution to give [SeCl₂Ph₂] ( 1 ) and [SeCl₂Ph₂(succinimide)₂] ( 2 ) as colourless crystals, which can be separated by fractional crystallization. According to X‐ray single crystal determinations both compounds contain [SeCl₂Ph₂] molecules with ψ‐trigonal‐bipyramidal coordination at the selenium atom, the chloro ligands being in apical positions. In 2 the dimeric unit (HNC₄O₂H₄)₂ is linked with its [SeCl₂Ph₂] unit via a weak C–H···O hydrogen bond. 1 : Space group Pbcn, Z = 4, lattice dimensions at 193 K: a = 1350.6(1), b = 573.3(1), c = 1503.3(2) pm, R₁ = 0.0326. 2 : Space group I2/a, Z = 4, lattice dimensions at 193 K: a = 1363.9(1), b = 557.7(1), c = 2781.3(1) pm, β = 101.01(1)°, R₁ = 0.0286.     

硒的土壤化学及其生物有效性

硒是重要的生命元素。高硒和低硒均会引起动物发生各种疾病，硒由土壤进入植物体，通过食物链控制着动物的硒营养状况，因此研究硒的土壤化学及其对生物的有效性对维护人类健康和牲畜生产是十分有意义的，本文拟就土壤中硒的含量、形态、有效性影响因素，硒的保健作用和调节措施等方面作一综述。     

Determination of trimethylselenonium iodide, selenomethionine, selenious acid, and selenic acid using high-performance liquid chromatography with on-line detection by inductively coupled plasma mass spectrometry or flame atomic absorption spectrometry

An analytical method has been developed for the determination of selenious acid, selenic acid, trimethylselenonium ion, and selenomethionine. The four selenium compounds were separated by HPLC on a column (25 cm×4 mm I.D.) of the anion-exchanger ESA Anion III with a mobile phase (1.5 ml/min) of 0.0055 M ammonium citrate (pH 5.5). Detection was carried out using an on-line inductively coupled plasma mass spectrometer (ICP-MS) or a flame atomic absorption spectrometer (FAAS) as the selenium-specific detector. The chromatographic parameters and the chemical factors affecting the separation of the selenium species were optimized. The four selenium compounds could be separated within 8 minutes. The detection limits of the coupled HPLC–FAAS system were approximately 1 mg Se/l for each compound (100 μl injection), estimated as three times the base-line noise of the chromatograms. More powerful selenium detection was achieved with an ICP-MS. Selenium was measured at m/z 78. To increase the nebulization efficiency, the Meinhard concentric glass nebulizer was replaced by an ultrasonic nebulizer. The ICP-MS signal intensity was increased with the ultrasonic nebulization by a factor of 7 times for selenious acid and 24 to 31 times for trimethylselenonium ion, selenomethionine, and selenic acid compared to that with the Meinhard nebulization. The detection limits achieved by the HPLC–ICP-MS with the ultrasonic nebulization were 0.08 μg Se/l for trimethylselenonium ion, 0.34 μg Se/l for selenious acid, 0.18 μg Se/l for selenomethionine, and 0.07 μg Se/l for selenic acid, respectively.     

Measurement of total selenium and selenium(IV) in seawater by stripping chronopotentiometry

We developed a stripping chronopotentiometric method (constant current stripping analysis, CCSA) with a mercury film electrode for selenium quantification in seawater. A sensitivity and detection limit of 222 ms ng^–1 l and 4 ng l^–1 (50 pM), respectively, were accomplished for a 3-min electrolysis time. Compared to the other chronopotentiometric methods available for a single selenium measurement only in natural waters, our procedure exhibits a ten times better sensitivity. It, therefore, allows one to reach the current concentration thresholds found in coastal and oceanic waters (30–200 ng l^–1). Moreover, a simple change in operating conditions enables one to also quantify Se(IV), a toxic dissolved species. With respect to the other electrochemical methods of current use, our procedure is beneficial because of its ease-of-use: it needs neither degassing step, nor catalyser.     

The first example of α-organoseleno arsonium ylides and its Wittig-type reaction

α-Organoseleno arsonium ylide 3 was synthesized for the first time by a phenylselenenylation-transylidation reaction. It has sufficient activity to carry out the Wittig-type reaction, affording a novel method for the stereoselective synthesis of (Z)-α-phenyl-seleno-α, β-unsaturated esters 6.     

Effects of interfering elements and chemical modifier on the activation energy of electrothermal atomization of selenium

In order to obtain additional insight into the mechanism of stabilization of selenium by palladium modification and to investigate the interference mechanism of Na, K, Mg and Ca on selenium atomization, the appearance temperature and the activation energy of atomization of selenium with or without the presence of the modifier and with or without the presence of the concomitant element, have been evaluated and discussed.     

陈爱敏,魏海英*

室温下,硒(IV)与邻苯二胺配位生成黄色配合物,用环己烷萃取后,在最大吸收波长330nm处测定其吸光度。实验结果表明：硒含量在4～20 μg/mL内线性关系良好,线性方程Y=0.1999C-0.0011(R=0.9995)。最优化条件下测定硒盐中硒的含量取得满意结果。该法操作简单,设备和药品价格低廉,准确度高,稳定性好,适宜于基层实验室对食品中微量元素硒的检验。     

Bridging Nonaselenium Ring in [Se9(IrBr3)2], and Three Modifications of the Mononuclear Complex [IrBr3(SeBr2)3]

The reaction of iridium powder with an excess of selenium and SeBr₄ yielded lustrous, vermillion crystals of the mononuclear iridium complex [IrBr₃(SeBr₂)₃]. The transition metal is coordinated octahedrally by three SeBr₂ and three bromide ligands with facial or meridional configuration. Three different modifications were obtained under similar conditions: a‐fac‐IrBr₃(SeBr₂)₃, space group P$\bar{1}$ , with a = 789.4(1) pm, b = 830.4(1) pm, c = 1334.4(1) pm, α = 81.634(5)°, β = 84.948(5)°, γ = 67.616(4)°; m‐fac‐IrBr₃(SeBr₂)₃, space group P2₁/n, with a = 1205.3(1) pm, b = 962.4(1) pm, c = 1383.9(1) pm, β = 91.114(3)°; mer‐IrBr₃(SeBr₂)₃, space group P2₁/n with a = 859.7(1) pm, b = 1284.3(1) pm, c = 1437.5(1) pm, β = 94.427(3)°. A lower bromine content in the starting composition resulted in shiny, deep‐red crystals of [Se₉(IrBr₃)₂]. X‐ray diffraction on a single‐crystal revealed a tetragonal lattice (space group I4₁/a) with a = 1245.4(1) pm and c = 2486.8(1) pm at 296(1) K. In the [Se₉(IrBr₃)₂] complex, a crown‐shaped uncharged Se₉ ring coordinates two iridium(III) cations as a bridging bis‐tridentate ligand. Three terminal bromide ions complete the distorted octahedral coordination of each transition metal atom.