金标记羟胺放大化学发光检测赭曲霉毒素A

以羧基磁性微球为分离载体,连接氨基捕获探针和适配体,加入生物素化报告序列和赭曲霉毒素A(Ochratoxin A,OTA)竞争结合适体,继续加入链霉亲和素纳米金和羟胺/Au~(3+)以显著提高化学发光检测OTA的灵敏度,从而建立了一种纳米金标记羟胺放大化学发光检测OTA的高灵敏度方法。优化了羧基磁性微球、氨基捕获探针、适配体、生物素化报告序列、链霉亲和素纳米金的用量。优化条件下,在OTA质量浓度0.01~50 ng/m L范围内,化学发光信号值与OTA浓度的对数呈较好的线性关系(r~2=0.992 5),检出限为1.58×10~(-3)ng/mL。对啤酒样品进行OTA加标回收实验,回收率为97.4%~105.4%,相对标准偏差为4.0%~5.5%。     

N2（A）及N（2D）对IF（X）的传能研究

在微波放电系统中,对NH_3-F-F_2-CF_3I体系进行研究,结果表明,向IF(X)传能的诸多媒介中,N_2(A)及N(~2D)起着主要作用,并且这一结论在经微波激发后的N_2与CF_3I的直接反应中得到了进一步证实。     

Detection of Metal Ions (Cu2+, Hg2+) and Cocaine by Using Ligation DNAzyme Machinery

The Cu²⁺‐dependent ligation DNAzyme is implemented as a biocatalyst for the colorimetric or chemiluminescence detection of Cu²⁺ ions, Hg²⁺ ions, or cocaine. These sensing platforms are based on the structural tailoring of the sequence of the Cu²⁺‐dependent ligation DNAzyme for specific analytes. The tethering of a subunit of the hemin/G‐quadruplex DNAzyme to the ligation DNAzyme sequence, and the incorporation of an imidazole‐functionalized nucleic‐acid sequence, which acts as a co‐substrate for the ligation DNAzyme that is tethered to the complementary hemin/G‐quadruplex subunit. In the presence of different analytes, Cu²⁺ ions, Hg²⁺ ions, or cocaine, the pretailored Cu²⁺‐dependent ligation DNAzyme sequence stimulates the respective ligation process by combining the imidazole‐functionalized co‐substrate with the ligation DNAzyme sequence. These reactions lead to the self‐assembly of stable hemin/G‐quadruplex DNAzyme nanostructures that enable the colorimetric analysis of the substrate through the DNAzyme‐catalyzed oxidation of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid), ABTS^2?, by H₂O₂ into the colored product ABTS^.?, or the chemiluminescence detection of the substrate through the DNAzyme‐catalyzed oxidation of luminol by H₂O₂. The detection limits for the sensing of Cu²⁺ ions, Hg²⁺ ions, and cocaine correspond to 1 nM , 10 nM and 2.5 μM , respectively. These different sensing platforms also reveal impressive selectivities.     

黄嘌呤氧化酶－乙醛－吖啶酯化学发光分析新体系

乙醛在黄嘌呤氧化酶催化作用下，被空气氧化生成乙酸和过氧化氢，酶反应生成的过氧化氢氧化新吖啶酯试剂［１０－甲基－９－（对甲酰苯基）吖啶羧酸酯氟磺酸盐］产生化学发光，化学发光强度与己醛浓度在一定范围内成线性关系．由此建立了一种化学发光分析新体系，用于测定乙醇含量．线性范围２．０×１０－７～１．２×１０－３ｍｏｌ／Ｌ，测定５．０×１０－７ｍｏｌ／Ｌ乙醛，相对标准偏差为６．８％，检测限为１．２×１０－７ｍｏｌ／Ｌ，测定环境水样中乙醇含量，取得满意结果，回收率为９５～１０６％．     

Confusion between dimethyl selenenyl sulfide and dimethyl selenone released by bacteria

Dimethyl selenone [(CH₃)₂SeO₂] has been reported in the literature as a metabolite released by bacteria in contact with selenium metal or selenium salts. In this study, mass spectral, chromatographic, and boiling-point data are presented that show that dimethyl selenone has been confused with dimethyl selenenyl sulfide (CH₃SeSCH₃). In addition, the headspaces above monocultures of selenium-resistant bacteria were examined using gas chromatography followed by fluorine-induced chemiluminescence detection. A number of alkyl sulfur and selenium species were detected, along with dimethyl selenenyl sulfide. A pathway from oxidized selenium salts to reduced methylated selenides and dimethyl selenenyl sulfide is also presented.     

利用CdTe量子点增敏鲁米诺-过氧化氢化学发光体系测定水环境中的对苯二酚

在碱性条件下,CdTe量子点对鲁米诺-过氧化氢化学发光体系具有显著的增敏作用,而对苯二酚对该体系的化学发光有强烈的抑制作用,以此建立了流动注射化学发光检测对苯二酚的新方法。在优化实验条件下,在1.0～25 nmol·L-1范围内对苯二酚的浓度与化学发光强度的抑制值ΔI呈良好的线性关系(R2=0.993 2),检出限为0.76 nmol·L-1,经实际应用证明,该方法可用于水环境中对苯二酚的测定。此外,对CdTe量子点增敏鲁米诺-过氧化氢化学发光体系的机理进行了探讨。     

Dielectric Barrier Discharge in Analytical Spectrometry

Abstract

Dielectric barrier discharge is a nonequilibrium plasma, and its industrial application has been on a large scale. Similarly, its prominent features of high dissociation ability at low working temperature and low power consumption, simple and adjustable configuration, ambient working conditions, and long lifetime are favorable for developing a wide array of analytical devices as well. This review addresses the basics of dielectric barrier discharge and emphasizes their analytical applications in analytical atomic spectrometry, chemiluminescence, gas chromatographic detectors, ion source for mass spectrometry, and ion mobility spectrometry with 103 references.     

Determination of β-Agonists in Porcine Urine by Molecularly Imprinted Polymer Based Chemiluminescence

Isoprenaline was used as the template to synthesize a molecularly imprinted polymer that was able to simultaneously recognize ten β-agonists. The simulation showed that the three-dimensional conformation of the template was the main factor responsible for the polymer’s recognition. The polymer particles were coated in the wells of a conventional microplate as the recognition reagent to prepare a chemiluminescence sensor. The light signal was initiated with a highly effective bis(2,4,6-trichlorophenyl) oxalate-H₂O₂-imidazole system. The assay contained only one sample-loading step followed by immediate data acquisition, so one measurement was complete within 12?min. The sensor was used to determine the ten analytes in porcine urine. The results showed that the senor achieved ultrahigh sensitivity, with limits of detection from 2.0 to 7.0?pg/mL, high recoveries from 78.6% to 99.4%, and satisfactory recycle performance up to seven times. This is the first study reporting a molecularly imprinted polymer based microtiter chemiluminescence sensor for the determination of β-agonists.     

Multibubble Sonoluminescence from a Theoretical Perspective

In the present review, complexity in multibubble sonoluminescence (MBSL) is discussed. At relatively low ultrasonic frequency, a cavitation bubble is filled mostly with water vapor at relatively high acoustic amplitude which results in OH-line emission by chemiluminescence as well as emissions from weakly ionized plasma formed inside a bubble at the end of the violent bubble collapse. At relatively high ultrasonic frequency or at relatively low acoustic amplitude at relatively low ultrasonic frequency, a cavitation bubble is mostly filled with noncondensable gases such as air or argon at the end of the bubble collapse, which results in relatively high bubble temperature and light emissions from plasma formed inside a bubble. Ionization potential lowering for atoms and molecules occurs due to the extremely high density inside a bubble at the end of the violent bubble collapse, which is one of the main reasons for the plasma formation inside a bubble in addition to the high bubble temperature due to quasi-adiabatic compression of a bubble, where “quasi” means that appreciable thermal conduction takes place between the heated interior of a bubble and the surrounding liquid. Due to bubble–bubble interaction, liquid droplets enter bubbles at the bubble collapse, which results in sodium-line emission.     

Study of blood collection and sample preparation for analysis of vitamin D and its metabolites by liquid chromatography–tandem mass spectrometry

The analysis of vitamin D status, with special emphasis on 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, is gaining interest in clinical studies due to the classical and non-classical effects attributed to this prohormone. In this research, the influence of the two steps preceding determination (viz. sample collection and preparation) on the quantitative analysis of vitamin D and its more important metabolites has been studied. Two preparation approaches, deproteination and solid-phase extraction (SPE), have been evaluated in terms of sensitivity to delimit their application, thus establishing that detection of 1,25-dihydroxyvitamin D cannot be addressed by protein precipitation. Concerning sample collection, serum and plasma reported high accuracy (above 83.3%) for vitamin D and metabolites, while precision, expressed as relative standard deviation, was below 12.9% for all analytes in both samples. Statistical analysis revealed that serum and plasma provided similar physiological levels for vitamin D₃, 24,25-dihydroxyvitamin D₃ and 25-hydroxyvitamin D₃, while significantly different levels were obtained for 1,25-dihydroxyvitamin D₃, always higher in plasma than in serum. Sample collection and treatment have proved to be significant in the analysis of vitamin D and its relevant metabolites.