用于活体和细胞内SO2衍生物检测的线粒体靶向双光子磷光铱(Ⅲ)配合物

暴露于高剂量的二氧化硫（SO₂）及其衍生物（SO₃^2-和HSO₃^-）会导致血管疾病甚至肺癌发生。双光子磷光成像显微术（TPPIM）和双光子磷光寿命成像显微术（TPPLIM）具有良好的时空分辨能力、抗光漂白、抗自体荧光以及较强组织穿透性等优点,可以实现SO₂衍生物在生物样品中实时检测。得益于铱配合物的长磷光寿命（~110 ns）和线粒体靶向特性,本文报道了首例基于TPPLIM技术的SO₂衍生物检测探针Ir-EA。Ir-EA对水溶液中的亚硫酸氢盐表现出高特异性和灵敏性的识别能力（69倍磷光增强,10倍亚硫酸氢盐）和较低的检测限（65 nmol·L^-1）。更为重要的是,Ir-EA对活细胞和斑马鱼的线粒体中SO₂衍生物表现出良好的成像效果。     

Determination of Silicate by Hollow Cathode Glow Discharge-Atomic Emission Spectrometry with Hydride Generation Technique

Abstract

Hollow cathode glow discharge atomic emission spectrometry has been applied to the determination of silicon coupled with a novel gaseous hydride generation technique, involving drying of an aqueous solution of silicate (sample) and mixing with powdered LiAlH₄. Sample introduction into the glow discharge chamber was performed via a pinhole at the center of the cathode which was connected to the hydride generator. The detection limit for silicon was 6μg at 288.1 nm and 30 μg at 251.6 nm.

     

Amperometric Biosensors Based on Platinum Nanowires

Abstract

Platinum nanowires (PtNW) were prepared by an electrodeposition strategy using nanopore alumina template. The nanowires prepared were dispersed in chitosan (CHIT) solution and stably immobilized onto the surface of glassy carbon electrode (GCE). The electrochemical behavior of PtNW‐modified electrode and its application to the electrocatalytic reduction of hydrogen peroxide (H₂O₂) are investigated. The modified electrode allows low potential detection of hydrogen peroxide with high sensitivity and fast response time. As an application example, the glucose oxidase was immobilized onto the surface of PtNW‐modified electrode through cross‐linking by glutaric dialdehyde. The detection of glucose was performed in phosphate buffer at –0.2 V. The resulting glucose biosensor exhibited a short response time (<8 s), with a linear range of 10^?5?10^?2 M and detection limit of 5×10^?6 M.     

基于异亮氨酸衍生物配体的配位聚合物的合成及其荧光应用

在溶剂热条件下,利用L-异亮氨酸衍生物配体(C₁₃H₁₉NO₃)与Zn(NO₃)₂·6H₂O合成了配位聚合物[Zn₂(C₁₃H₁₇NO₃)₂]_n (1)。单晶X射线衍射结果显示化合物1结晶于单斜晶系P2₁空间群,配体与金属离子桥联形成二维层状结构,层与层间通过范德瓦耳斯力形成了三维超分子网络结构。在化合物1合成过程中加入罗丹明B(Rho-B),可以得到复合材料2。荧光测试结果显示,在激发波长为370 nm时,化合物1主要是基于配体的发光,而复合物2除配体的发光外,在580 nm处出现了Rho-B的发射峰。利用配体与Rho-B发射峰相对强度的比值为检测信号,将复合物2应用于金属阳离子和挥发性有机物(VOCs)检测。实验结果显示该材料能在水溶液中选择性识别Cr³⁺离子,并且在短时间内对苯...     

A Superacid-catalyzed Synthesis of Fluorescent Covalent Triazine Based Framework Containing Perylene Tetraanhydride Bisimide for Sensing to O-nitrophenol with Ultrahigh Sensitivity

Abstract

A mesoporous covalent triazine framework, PCPDI, was synthesized via an aromatic nitrile trimerization reaction of N,N′-di(4-cyanphenyl)- 3,4,9,10-tetracarboxydiimide (CPDI) by CF₃SO₃H catalyzed at 40?°C and this method avoids the use of noble metal catalyzers or high temperature reaction. PCPDI exhibits high thermal stability and strong fluorescence. The PCPDI shows ultrahigh sensitivity to tracing o-nitrophenol in chloroform with K_SV constant of 1.74?×?10⁵ L mol^?1 and detection limit (LOD) of 1.72?×?10^?11?mol L^?1.     

Synthesis and characterization of M(II) (M = Cd,Hg and Pb) complexes with naphthodiaza-crown macrocyclic ligand and study of metal ion recognition by fluorescence, 1H NMR spectroscopy,and DFT calculation

To find metal ion recognition by L (L = O₂N₂-donor naphthodiaza-crown macrocyclic ligand), the complexes [ML]²⁺ (M = Cd, Hg and Pb) were synthesized and characterized by IR, ¹H, ¹³C NMR, and mass spectrometry, as well as elemental microanalysis. Hg(II) showed perceptible enhancement of the fluorescence of L in which ultra-low limit of detection for Hg(II) by L was determined as 1 nM in ethanol and DMSO. L reserved selectivity of Hg(II) in its binary mixtures with metal cations in solution. A 1 : 1 stoichiometry was found for the interaction of Hg(II) with L while Benesi–Hildebrand method was applied to calculate its complexation binding constant (K_BH) employing fluorescence spectrophotometry. The monitoring of the chemical shifts in ¹H NMR spectra of these complexes demonstrated that the central macrocycle of L was tailored for the size of Hg(II). Density functional theory calculations using B₃LYP/6–31G* basis set demonstrated that the macrocycle cavity of L was properly fitted for complex formation with Hg(II) cation, while both Cd(II) and Pb(II) cations did not form strong bonds with L from inadequate cation size. The present study shows detection method of Hg(II) and also possible application of naphthodiaza as an appropriate fluorophore macrocyclic ligand for detecting other metal ions.     

High-Performance Liquid Chromatography of Fungicides in Citrus Fruits

Abstract

The determination of three common citrus fungicides, diphenyl (DP), o-phenylphenol (oPP) and thiabendazole (TBZ), was investigated with reversed-phase high-performance liquid chromatography. DP and oPP were successfully chromatographed and quantitated by utilizing a reversed-phase Unisil Q C₁₈ column after extraction with an essential oil distillation apparatus. An acetonitrile-0.1M H₃PO₄ (55:45) mobile phase was used. TBZ was chromatographed by using a Unisil Q C₈ column with a mobile phase of acetonitrile-0.1M H₃PO₄ (80:20) after the extraction with ethyl acetate. The fungicides were detected with fluorescence detection at typical residue levels on citrus. The     

Observation of nicotinic acid in nicorandil samples and simultaneous determination of nicorandil and its three degradation products in raw drug and tablet form by high performance liquid chromatography

Nicotinic acid (NA) as a degradation product of nicorandil (NIC) was identified and quantified by HPLC-DAD and GC / MS. In the present paper a rapid, sensitive, precise and specific HPLC-DAD method was developed for the simultaneous determination of NIC, NA and two known degradation products, nitrate (NI) and de-nitrated nicorandil [N-(2-hydroxyethyl) nicotinamide] (HEN) in raw drug and tablet form. The present method was performed on an ODS C₁₈ column (150 × 4.6 mm, 5 μm) using detection at 204 nm and employing nicotinamide (NT) as internal standard. The procedure was validated by evaluating linearity, accuracy and recovery and applied to monitor the increased level of NI, HEN and NA as a function of NIC storage time at room temperature.     

Reverse-Phase High-Performance Liquid-Chromotographic DAD Method for Simultaneous Determination of Five Isoflavones in Millettia nitida var. hirsutissima

Abstract

A reverse-phase high-performance liquid-chromatographic photodiode array detection (DAD) method has been developed and validated for the simultaneous determination of five isoflavones in Millettia nitida var. hirsutissima: hirsutissimiside B, sphaerobioside, lanceolarin, formononetin, and afromosin. The method utilized a C₁₈ column (4 µm, 250 × 4.6 mm) with an acetonitrile and aqueous H₃PO₄ gradient and ultraviolet detection at 259 nm. The recovery of the method is 94.1–105.9%, and linearity (r > 0.9996) is obtained for all the isoflavones.     

Determination of Ascorbic Acid and Dehydroascorbic Acid in Blood Plasma Samples

Abstract

Following the stabilization of the plasma samples with HClO₄ and EDTA, the samples could be directly analyzed by HPLC using electrochemical detection and reversed-phase columns. The accuracy and precision of the method was evaluated using plasma samples spiked with ascorbic acid (10 μg/ml) and the results were also compared to the classical colorimetric procedure. Dehydroascorbic (5 μg/ml) was determined in plasma samples using UV detection following derivatization at room temperature for 45 minutes with o-phenylenediamine.     

Formation of Isoindole Derivatives of Sulfidopeptide Leukotrienes by Reaction with O-Phthalaldehyde and Separation by Reverse Phase High Performance Liquid Chromatography

Abstract

A method is described for the formation of fluorescent conjugates of the sulfidopeptide leukotrienes (LTC₄, LTD⁴, and LTE⁴) by reaction of the primary amine moiety of these metabolites with o-phthalaldehyde. Separation of the fluorescent derivatives was achieved by reverse-phase high performance liquid chromatography in less than 30 minutes using a convex gradient of methanol-50 mM Na Acetate-5% Tetrahydrofuran pH 5.5. Detection limits realized under the conditions described were 0.35 ng, 3.8 ng and 3.7 ng for LTC₄, LTD₄, and LTE₄, respectively. This represents an Increased sensitivity over detection of these metabolites by ultra-violet spectroscopy. The leukotriene-OPA derivatives are fully stable for 50 minutes at 23°C and for at least 4 hours at 0°C. The method is applied to the detection of LTC₄ generated by zymosan stimulated murine peritoneal macrophages.     

Determination of Niacin in Cereal Samples by HPLC

Abstract

A liquid chromatographic method for the analysis of niacin in cereal products is presented. The sample is extracted in the presence of Ca(OH)₂, concentrated and purified on an anion exchange resin, and further cleaned up by oxidation with KMnO₄. Final quantitation is by HPLC with ultraviolet detection at 254 nm.

Using a μBondapak C₁₈ column, a mobile phase consisting of 5% methanol in water containing 0.005 M tetrabutyl ammonium phosphate, and a flow rate of 2.0 ml/min., niacin was found to have a retention time of about 7 minutes.     

An Accurate,Specific HPLC Method for the Analysis of a Decapeptide in a Lactose Matrix

Abstract

A high-performance liquid chromatographic (HPLC) method is described for the determination of an analog of the hormone LH-RH in lyophilized vials at the low parts-per-million level. The peptide (Schally analog) is quantitatively recovered from the glass lyophilization vials after reconstitution with mobile phase. The peptide solution is eluted on a reversed-phase, C₁₈ column and monitored with ultraviolet (UV) detection at 220 nm. The chromatography resolves Schally analog from a number of synthetic impurities and decomposition products.     

Preconcentration of albumin on silica with attached groups of polyoxyethylated isooctyl phenol

The potencies of silica with attached groups of polyoxyethylated isooctyl phenol (SiO ₂ -TX) as an adsorbent for the solid phase extraction (SPE) preconcentration of bovine serum albumin (BSA) in urine are examined. SiO₂-TX is shown to effectively extract BSA (up to 96%) as an ion associate with cationic (at pH 8) and anionic (at pH 1.5) surfactants. The maximal capacity of SiO₂-TX to BSA makes 33 mg/g in the presence of octylpyridinium bromide, 27 mg/g in the presence of cetyltrymethylammonium bromide or sodium dodecylsulfate with the linearity range in Henri’s area up to 23 and 20 mg/g of SiO₂-TX, respectively; the distribution coefficients attain 1.8 × 10³ mL/g. BSA is eluted quantitatively with 1–4 mL of acetonitrile containing NaOH, which makes possible the use of adsorbent for the reaction of protein with trifluoroethanol (TFE) before its photometric determination by the Lowry method. The influence of accompanying urine components is studied, i.e., urea, glucose, Na⁺, K⁺, Mg²⁺, chlorides, and phosphates, on the efficiency BSA extraction from model aqueous solutions on SiO₂-TX. The detection limit for BSA makes 4 mg/L and the analytical range, from 12 to 140 mg/L.     

A pillar-layered Cd(II) metal-organic framework for selective detection of organic explosives

The detection of explosives is crucial for homeland security, environmental cleaning, and military issues. As a new class of porous materials, metal-organic frameworks (MOFs) are promising platforms for the detection of organic explosives. In this work, a new pillar-layered Cd(II) MOF, [CdL_0.5dpe_0.5]·2H₂O (BUT-202, H₄L = 4,8-disulfonaphthalene-2,6-dicarboxylic acid, dpe = 1,2-bis(4-pyridyl)ethylene), was synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, and elemental analysis. BUT-202 has good fluorescent properties, which can be selectively quenched by trace amounts of 2,4,6-trinitrophenol (TNP) in DMF with low detection limit of 0.2 μM.     

基于4-(2,4-二羧基苯氧基)邻苯二甲酸配体的锌配位聚合物的合成、结构及其荧光传感性能

基于H₄dpa和bpy(H₄dpa=4-(2,4-二羧基苯氧基)邻苯二甲酸,bpy=4,4''-联吡啶)为配体,在水热条件下设计、合成了金属锌配位聚合物(Zn-CP)[Zn(H₂dpa)(bpy)_1.5]_n (1),并用元素分析、红外光谱、X射线单晶衍射等对其进行了结构表征。在1中相邻Zn²⁺与H₂dpa^2-离子和bpy配位形成的一维双链结构,相邻的一维双链通过氢键作用扩展形成三维超分子网结构。荧光研究表明:1是一种灵敏度高、选择性好、多响应的荧光传感器,可用于农药和硝基爆炸物的检测。有趣的是,2,4,6-三硝基苯(TNP)和嘧霉胺(Pth)对1的荧光发射显示出明显的猝灭效果,而抑霉唑(Ima)对1有荧光增强效果。此外,通过紫外可见吸收光谱、荧光寿命以及X射线光电子能谱探究了1的荧光传感机理。     

HPLC Analysis of Adriamycine as N-2,4-Dinitrophenyladriamycine

Abstract

Derivatization of adriamycine (I) by reaction with 2,4-dinitrofluorobenzene, followed by HPLC analysis on reversed phase (RP-18 μ-Bondapak) or on normal phase (μ-porasil) and detection at 482 nm, provides a fast method (R_f=4.0 min) for determination of adriamycine [as N-2,4-dinitrophenyladriamycine (III)] in the 1–10 ppm range. Reaction with 2,4-dinitrofluoro[^?14C]benzene, followed by HPLC separation and detection on a γ counter, extends the detection limit to 0.04 ppm adriamycine.     

Crystal structure and protective effect in osteoarthritis of Co(II)-mediated pyridinium-bearing coordination polymer

Abstract

By using a mixed-ligand approach, a new Co(II)-mediated pyridinium-bearing coordination polymer, {[Co(BCbpe)(ipa)]·3H₂O}_n (1), has been prepared by reaction of Co(NO₃)₂·6H₂O) and isophthalic acid (H₂ipa) in the presence of pyridinium chloride 1-(4-carboxybenzyl)4-[2-(4-pyridyl)-vinyl] (HBCbpeCl) in EtOH/H₂O (V:V?=?1:1). Furthermore, a green hand grinding technique has been implemented to reduce the particle size of 1 to generate nanosheets of 1 with good water dispersivity. The post-traumatic osteoarthritis (OA) model was constructed and the in vivo protective effect of nano 1 was evaluated. First, the inflammatory level of OA rats was measured by ELISA detection. Second, for further detection, the real-time RT-PCR was carried out to measure the relative expression of caspase-1, nlrp3 as well as il-1β inflammatory factors. Finally, molecular docking analysis of the complex indicated that all of the proposed drug candidates showed desirable drug-like criteria.     

High-Performance Liquid Chromatography of Domoic Acid,a Marine Neurotoxin,with Application to Shellfish and Plankton

Abstract

A recent outbreak of poisoning resulting from the consumption of cultured blue mussels (Mytilus edulis L.) from a localized area in Eastern Canada has been attributed to the presence of domoic acid (1), a relatively rare neurotoxic amino acid, previously found only in some algae of the family Rhodomelaceae. Studies on aqueous extracts of shellfish tissue indicated that the toxin and several of its isomers could be separated (and isolated in sufficient amounts for subsequent structural identification) by reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet (UV) diode array detection (DAD). Aqueous acetonitrile containing 0.1% v/v trifluoroacetic acid was used as mobile phase. As the retention time and characteristic UV absorption spectrum of 1 (λ_max = 242 nm) permit unequivocal identification, the HPLC-DAD procedure was refined with a microbore column to provide a rapid (5 min), sensitive (0.3 ng detection limit) and reproducible assay method for the determination of 1 in shellfish tissue. Extraction was accomplished by boiling homogenized shellfish tissue for 5 min with distilled water. Extracts were taken through an octadecylsilica solid phase extraction clean-up prior to HPLC. This method has been applied to a variety of shellfish and phytoplankton samples.

BRIEF

Reversed-phase HPLC with ultraviolet diode array detection was used to analyze shellfish tissue and phytoplankton extracts for domoic acid. A rapid (5 min) and sensitive (0.3 ng detection limit) assay is presented.     

Simultaneous Separation and Determination of Different Polar Flavonoids in Multiflora Fruit by Reverse-Phase High-Performance Liquid Chromatography

Abstract

A method for the determination of different polar flavonoids from multiflora fruit by reverse-phase high-performance liquid chromatography (HPLC) is presented in this article. Chromatographic separation of these flavonoids was performed over a Diamonsil C₁₈ column (200 mm × 4.6 mm × 5 µm) using gradient elution with an isopropanol–methanol–water mixture at 25°C, at a flow rate ranging from 0.5 to 1.5 mL/min and detection at 360 nm. The flavonoids could be separated within 6 min; the recovery was between 96% and 104%, and the relative standard deviation was 1.6–2.6%. This method allows rapid detection of flavonoids.