Synthesis and Crystal Structure of Macrocyclic Cavitand Cucurbit[5]uril and Its Supramolecular Adduct with Cu（Ⅱ）

The first supramolecular adduct (H₃O)₂[Cu(H₂O)₄](SO₄)₂·2(C₃₀H₃₀N₂₀O₁₀)·₂₄(H₂O) based on cucurbit[5]uril was synthesized and characterized by single crystal X‐ray diffraction analysis. In the adduct, copper ion is coordinated by four oxygen atoms from H₂O. The latter links two cucurbit[5]uril molecules due to a complicated hydrogen bonding containing lattice water molecules.     

5-(5-氟-2-吡啶偶氮)-2,4-二氨基甲苯与钴显色反应的研究及应用

研究了新合成试剂5-(5-氟-2-吡啶偶氮)-2,4-二氨基甲苯(5-F-PADAT)与钴(Ⅱ)的显色反应。实验表明,在pH4.7~9.0范围内,钴与试剂形成紫红色配合物,其最大吸收波长位于506 nm。该配合物在无机酸作用下,可转化为另一具有较高吸收特性的质子化型体,最大吸收波长红移到565 nm,适宜的酸浓度范围分别为:0.24~3.6 mol/L HClO4、0.16~3.84 mol/L H2SO4、0.48~2.4 mol/L HCl、0.64~3.84 mol/L H3PO4。配合物表观摩尔吸光系数ε565=9.1×104L.mol-1.cm-1,钴(Ⅱ)质量浓度在0~0.5μg/mL内符合比尔定律。所拟方法已应用于维生素B12针剂中微量钴的测定。     

2－（5－Br－2－吡啶偶氮－5－二乙氨基）－酚与铑的显色反应的研究及应用

本文研究了２－（－５－Ｂｒ－２吡啶偶氮－５－二乙氨基）－酚与铑（Ⅲ）的显色反应。在ｐＨ为４．０的邻苯二甲酸氢钾缓冲液介质中，Ｒｈ（Ⅲ）与试剂形成稳定的橙红色络合物，其组成比为１：４，最大吸收波长为４９０ｎｍ，表现摩尔吸光系数为１．３×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。铑含量在０～４μｇ／１０ｍＬ范围内服从比尔定律。     

2-(苯并吖啶酮)-乙基咪唑酸酯探针对荧光和质谱的双增敏作用

采用3种不同衍生方法对胺类化合物进行标记,比较衍生效率的差别,给出最优方法:5-(2-羟乙基)-(苯并吖啶酮与N,N-羰基双咪唑(CDI)缩合形成的双敏感探针2-(苯并吖啶酮)-乙基咪唑酸酯(BAEIC)与胺的衍生效率最高,产物稳定。BAEIC在N,N-二甲基甲酰胺(DMF)溶剂中以4-二甲氨基吡啶(DMAP)为催化剂,在80℃条件下与胺反应生成的亲核取代物,不仅表现出强烈的荧光,同时具有很强的质谱离子化能力。估算了衍生物在乙腈和甲醇水溶液中百分离子化值δ在5.62%～58.08%和2.14%～56.58%范围内。本方法具有良好的重现性,激发和发射波长为λex/λem=280/510nm,荧光检出限为0.12～0.59μg/L(8.6～79fmol);在线APCI-MS检出限为1.9～14μg/L(544～825fmol)。     

Development of an ultrasensitive stacking technique for 5‐nitroimidazole determination in untreated biological fluids by micellar electrokinetic chromatography

Cation‐selective exhaustive injection and sweeping followed by a MEKC separation is evaluated for the sensitive analysis of 5‐nitroimidazoles in untreated human serum and urine. Deproteinized serum and urine samples were diluted 76 and 143 times, respectively, in a low‐conductivity solvent (5.00 mM orthophosphoric acid containing 5.0% v/v methanol). Samples were electrokinetically injected at 9.8 kV for 632 s in a previously conditioned fused‐silica capillary (65.0 cm × 50 μm id). Separation was performed at –30 kV and 20°C using 44 mM phosphate buffer (pH 2.5), 123 mM SDS, and 8% v/v tetrahydrofurane as BGE. Signals were monitored at 276 nm and peak area was selected as analytical response. Good linearity (R² ≥ 0.988) and LODs lower than 1.5 and 1.8 μg/mL were achieved in serum and urine, respectively.     

2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺与钯显色反应的研究

本文研究了5-Br-PADMA与钯的显色反应,在0.2～3.0mol/L HClO_4溶液中,试剂与钯形成最大吸收峰位于609nm,表观摩尔吸光系数ε为8.2×10~4L·mol~(-1)·cm~(-1)的青蓝色配合物。钯含量在0～35μg/25ml范围内符合比尔定律。大量常见金属离子及十倍量的铂、金、铱、铑和钌等贵金属离子不干扰钯的测定。所拟方法简便、快速、选择性高且测定结果稳定。直接应用于含钯样品的分析,结果满意。     

5-[2-(5-甲基-1,3,4-噻二唑)偶氮]-8-羟基喹啉的合成及其与铜的显色反应研究

合成了新型偶氮显色剂:5-[2(5-甲基-1,3,4-噻二唑)偶氮]-8-羟基喹啉(简称MTADQ),并研究了它与铜的显色反应。实验结果表明:在pH 5.8~7.8的水溶液中该试剂与铜离子形成一种稳定的黄色络合物,其最大吸收波长位于530 nm处,表观摩尔吸光系数ε=9.5×104L.mol-1.cm-1,配合物的组成比为1∶1。铜离子质量浓度在0~1.2 mg/L范围内服从朗伯-比尔定律。已用于测定矿石样品中的微量铜。     

Synthesis, Characterization, Spectroscopic Properties of 2-（4-Dimethylaminophenyl）-5-fluoro-6-（morpholin-4-yl）-1H-benzimidazole and its Interaction with Calf Thymus DNA

Benzimidazole compounds have attracted a renewed interest recently owing to theirpotential applications in high-performance composite materials, electronic chemicals,photosensitive materials, and their special potentials in biological and/or medicinalapplication1,2. Typically, aromatic compounds with near planar structures and contain-ing hydrogen-donor groups or groups, which are capable of being protonated, havespecial interactions with DNA via intercalation, hydrogen-bonding, and so on3.Me…     

A sensitive LC-MS/MS method for quantification of phenytoin and its major metabolite with application to in vivo investigations of intravenous and intranasal phenytoin delivery

Phenytoin is a powerful antiseizure drug with complex pharmacokinetic properties, making it an interesting model drug to use in preclinical in vivo investigations, especially with regards to formulations aiming to improve drug delivery to the brain. Moreover, it has a major metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin, which can be simultaneously studied to achieve a better assessment of its behaviour in the body. Here, we describe the development and validation of a sensitive LCMS/MS method for quantification of phenytoin and 5-(4-hydroxyphenyl)-5-phenylhydantoin in rat plasma and brain which can be used in such preclinical studies. Calibration curves produced covered a range of 7.81 to 250 ng/mL (plasma) and 23.4 to 750 ng/g (brain tissue) for both analytes. The method was validated for specificity, sensitivity, accuracy, and precision and found to be within the acceptable limits of ±15% over this range in both tissue types. The method when applied in two in vivo investigations: validation of a seizure model and to study the behaviour of a solution of intranasally administered phenytoin as a foundation for future studies into direct nose-to-brain delivery of phenytoin using specifically developed particulate systems, was highly sensitive for detecting phenytoin and 5-(4-hydroxyphenyl)-5-phenylhydantoin in rat plasma and brain.     

微乳液的增敏作用研究──Ni（Ⅱ）－5－Br－PADAP的分光光度法测定

以含水量８０％的阴离子型ＳＤＳ／ｎ－Ｃ＿（５）Ｈ＿（１１）ＯＨ／ｎ－Ｃ＿（７）Ｈ＿１６／Ｈ＿（２）Ｏ微乳液为介质，进行了Ｎｉ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ的分光光度研究，其表观摩尔吸光系数为１．１３×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），与相应含水量的ＳＤＳ胶束介质比较，测定的灵敏度显著提高（后者为７．５×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）），样品分析结果令人满意。     

1-Bromo-2-trifluoroacetylcyclobutenes as novel building blocks for the construction of trifluoromethyl substituted heterocycles. Part 1: Synthesis of 5-(trifluoromethyl)-2(5H)-furanones condensed with substituted cyclobutenes

The regioselective reduction of substituted 1-bromo-2-trifluoroacetylcyclobutenes by lithium aluminium hydride affords corresponding brominated alcohols, which, under the treatment of two equivalents of butyllithium, give new lithiated cyclobutenes. Their carboxylation followed by lactonization induced by trifluoroacetic anhydride appeared to be an effective approach towards 5-trifluoromethylated furanones condensed with substituted cyclobutene rings.     

An enhanced liquid chromatographic method for 5-hydroxymethylfurfural determination in UHT milk

Summary An enhanced method of HPLC for the determination of 5-Hydroxymethyl-2-furfuraldehyde (HMF) in fluid milk was perfected. Its resolving capacity permitted the specific separation of this compound. The real concentration (mol/l) of HMF was determined and not the HMF value, as in the colorimetric analysis, where an intermediary coloured compound (HMF-TBA) is utilised. The optimum pH condition (pH=4.0–4.2) for the mobile phase to prevent overlapping between the HMF peak and the peaks of the other compound ( and ) that coeluted with the HMF and also the optimum organic solvent content (3% or 7%) were established. This is a sensitive, quick and safe method for the determination of HMF in fluid milk.Research funded by CICYT n. ALI-173.     

在线预处理对乙二胺四乙酸二钠离子色谱分离的影响及其应用

1引言乙二胺四乙酸二钠(EDTA-2Na)作为食品添加剂,能够对原料中的微量金属离子进行络和,防止金属离子对产品质量的缓慢破坏作用[1],常用在果蔬罐头、八宝粥等食品中,同时也可作为蛋白洗涤液中的添加剂,既增加舒适度又提高溶液杀菌能力。但是含量过高,会刺激皮肤和粘膜,引起哮喘等疾病,国家标准规定食品中最高限量为     

新试剂5-(对羧基苯偶氮)-8-羟基喹哪啶与铂(Ⅳ)显色反应的研究及应用

合成了新试剂5-(对羧基苯偶氮)-8-羟基喹哪啶(5-CPAHQD),并用分光光度法研究了其与铂(Ⅳ)的显色反应。结果表明,在pH=2.0~3.05的HCl—邻苯二甲酸氢钾缓冲溶液中,在乳化剂OP的存在下,试剂与铂(Ⅳ)形成1∶1的稳定红色络合物。建立了测定铂的光度法新体系,其最大吸收波长λmax=490nm,表观摩尔吸光系数ε=5.80×105L.mol-1.cm-1。铂(Ⅳ)的质量浓度在0.02~0.32μg/mL内符合比尔定律。方法用于测定美国蜂窝废催化剂中的铂,结果与原子吸收法相符,平行测定5次的RSD在0.75%~2.38%之间。     

2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与钯显色反应的研究

本文研究了3,5-diCl-PADMA与钯的显色反应。在0.5～4.8mol/L HClO_4溶液中,试剂与钯形成稳定的1:1配合物,其最大吸收波长为616nm,表观摩尔吸光系数为8.38×10~4L·mol~(-1)·cm~(-1)。大量的铜、钴、镍及一定量贵金属离子不干扰钯的测定。所拟方法直接应用于含钯样品的分析。     

Separation behavior of U(VI) and Th(IV) on a cation exchange column using 2,6-pyridine dicarboxylic acid as a complexing agent and its application for the rapid separation and determination of U and Th by ion chromatography

The retention behavior of U and Th as their 2,6-pyridine dicarboxylic acid (PDCA) complexes on a cation exchange column was investigated under low pH conditions. Based on the observed retention characteristics, an ion chromatographic method for the rapid separation of uranium and thorium in isocratic elution mode using 0.08 mM PDCA and 0.24 M KNO(3) in 0.22 M HNO(3) as the eluent was developed. Both uranium and thorium were eluted as their PDCA complexes within 2 min, whereas the transition and lanthanide metal cations were eluted as an unresolved broad peak after thorium. Under the optimized conditions both U and Th have no interference either from alkali and alkaline earth elements up to a concentration ratio of 1:500 or from other elements up to 1:100. The detection limits (LOD) of U and Th were calculated as 0.04 and 0.06 ppm, respectively (S/N=3). The precision in the measurement of peak area of 0.5 ppm of both U and Th was better than 5% and a linear calibration in the concentration range of 0.25-25 ppm of U and Th was obtained. The method was successfully applied to determine U and Th in effluent water samples.     

新型三氮烯试剂与阴离子表面活性剂相互作用的荧光光谱法研究

自制新型1-(5-萘酚-7-磺酸基)-3-[(4-偶氮苯基)苯基]-三氮烯(NASAPAPT)试剂作为荧光试剂,研究其与阴离子表面活性剂十二烷基苯磺酸钠(SDBS)的荧光性能.结果表明,NASAPAPT与SDBS产生荧光猝灭作用,在优化的实验条件下,测定SDBS的线性范围为2.52×10-8～1.06×10-6 mol,L-1内,检出限为1.93×10-8 moL·L-1.方法应用于环境水样中痕量SDBS的测定,回收率在98.39％～102.460％.计算了NASAPAPT与SDBS的热力学函数,表明它们之间主要靠范德华力结合.     

4-(5-硝基-2-吡啶偶氮)-1,3-二氨基苯与铑(Ⅲ)显色反应的研究及其应用

研究了新合成试剂4-(5-硝基-2-吡啶偶氮)-1,3-二氨基苯(5-NO2-PADAB)与铑(Ⅲ)的显色反应.结果表明,在pH 3.3～4.7的乙酸-乙酸钠缓冲介质中,5-NO2-PADAB与铑形成2∶1的紫红色络合物,其最大吸收波长位于524 nm.该络合物在1.2 mol/L HClO4介质中可质子化转变为另一种型体的紫蓝络合物,最大吸收波长红移至580 nm,其表观摩尔吸光系数提高至1.52×105 L·mol-1·cm-1,以EDTA为掩蔽剂,大量常见金属离子不干扰测定.铑含量在0～0.8 μg/mL内符合比尔定律.所拟方法可应用于催化剂中微量铑的测定.     

Solid-Phase Organic Synthesis of Methyl Isoxazole-5-carboxylates Based on Wang Resin–Bound 1-Phenylselenoacrylate

A novel Wang resin–bound 1-phenylselenoacrylate reagent has been developed and used as dipolarophile for the 1,3-dipolar cycloaddition with nitrile oxides to the regioselective synthesis of methyl 3-substituted isoxazole-5-carboxylates in good yields and purities.