空气—氩气混合气冷却ICP—AES中钙,钡,铜,锌元素的谱线强度和信？…

研究了小功率空气－氩气混合气冷却ＩＣＰ中４种元素（钙、钡、铜、锌）、８和谱线的强度和信背比随冷却气组成及观测高工估算了折中条件下的检出限。对于离子线及激发电位较高的原子线,冷却气中引入体积分数为５－１０％空气后,谱线强度最大并大于Ａｒ－ＩＣＰ中数值;对于激发发电位较低的原子线,随着气中空气含量的增大其谱线强度逐渐减小,谱线的信背比则与激发电位及谱线波长有关。     

空气-氩气混合气冷却ICP-AES中钙、钡、铜、锌元素的谱线强度和信背比的研究

研究了小功率空气－氩气混合气冷却ＩＣＰ中４种元素（钙、钡、铜、锌）、８条谱线的强度和信背比随冷却气组成及观测高度的变化,并估算了折中条件下的检出限。对于离子线及激发电位较高的原子线,冷却气中引入体积分数为５％～１０％空气后,谱线强度最大并大于Ａｒ－ＩＣＰ中数值;对于激发电位较低的原子线,随着冷却气中空气含量的增大其谱线强度逐渐减小。谱线的信背比则与激发电位及谱线波长有关     

盐酸表柔比星与核酸相互作用的共振瑞利散射光谱研究及其分析应用

用共振瑞利散射光谱研究了盐酸表柔比星(EPI)与小牛胸腺DNA(ctDNA)、鲑鱼DNA(sDNA)、鲱鱼精DNA(hsDNA)和酵母RNA(yRNA)等核酸之间的相互作用. 实验表明在pH 2.0左右的酸性介质中, 表柔比星及核酸本身的共振瑞利散射(RRS)均十分微弱, 但是当它们相互作用形成结合产物时, 将导致RRS增强并出现新RRS光谱. 不同核酸与表柔比星结合产物的RRS 光谱特征略有差异, 散射增强程度则各不相同, 其相对散射强度的顺序是ctDNA≈sDNA＞hsDNA＞yRNA . 在一定范围内核酸浓度与散射强度成正比, 据此可以建立一种新的用表柔比星测定DNA的 RRS 法, 方法具有高灵敏度, 对于不同DNA 其检出限(3s)在24.0 ng/mL 至28.0 ng/mL 之间, 用于合成样品分析, 结果满意. 文中还研究了适宜的反应条件, 影响因素和结合产物的分析化学性质. 结合吸收光谱和荧光光谱特征对表柔比星与DNA 的反应机理进行了讨论.     

砷、锑、铋的非水介质氢化物发生-高频感耦等离子体原子发射光谱分析的研究

本文尝试了非水介质氢化物发生法与ICP-AES相结合测定As、Sb、Bi的方法。用商品的连续氢化物发生器比较了几种非水介质体系,并给出了KBH_4浓度,MIBK与甲酸的混合比例,观察高度、载气流量和等离子体正向功率对信背比和检出限影响的结果。在所用的条件下,As、Sb、Bi的检出限分别为0.8,4.3和0.5ng/ml,与水溶液中氢化法的结果相近。     

环境样品中痕量甲醛的催化荧光动力学分析

基于在硫酸介质中, 痕量甲醛能促进溴酸钾氧化吡咯红并使其荧光强度减弱的反应, 建立了动力学荧光法分析测定痕量甲醛的新方法. 研究了温度、时间, 各种试剂浓度等条件对测定的影响. 在最佳实验条件下, 方法的线性范围是8～200 ng/mL, 检出限为6.1 ng/mL. 该方法用于环境水样、室内空气、食品中痕量甲醛的测定, 并与乙酰丙酮分光光度法进行了对照, 结果无显著性差异.     

硫化镉纳米微粒作探针共振瑞利散射测定某些蒽环类抗癌药物

在pH=5.0—9.0的水溶液中, 硫化镉纳米微粒[(CdS)n]与蒽环类抗生素米托蒽醌(MXT)、 表柔比星(EPI)和柔红霉素(DNR)凭借静电引力及疏水作用力结合, 形成粒径更大的聚集体, 导致共振瑞利散射(RRS)的增强并产生新的RRS光谱, 最大的RRS峰位于292 nm(MXT体系)、 285 nm(DNR体系)和315 nm(EPI体系). 与此同时还观察到二级散射(SOS)和倍频散射(FDS)强度明显提高. 其最大SOS峰位于540 nm(MXT体系)和560 nm(EPI及DNR体系), 而最大的FDS峰分别位于335 nm(MXT体系)、 320 nm(EPI体系)和330 nm(DNR体系). 在一定条件下, 3种散射强度(ΔI)均与药物的浓度成正比, 反应具有高灵敏度, 对于3种药物的检出限在3.6—9.1 ng/mL之间. 其中(CdS)n-MXT体系灵敏度最高, 对MXT的检出限分别为4.1 ng/mL(RRS)、 3.8 ng/mL(SOS)和3.6 ng/mL(FDS). 据此发展了一种用纳米硫化镉作探针, 灵敏、 简便并快速测定蒽环类抗癌药物的共振瑞利散射新方法.     

酶联免疫法检测动物组织及尿液中氟苯尼考与甲砜霉素的残留

针对食品中氟苯尼考及甲砜霉素多残留污染问题,基于新设计的半抗原制备了系列人工抗原,通过免疫动物获得了可同时特异性识别氟苯尼考与甲砜霉素的多克隆抗体,并在抗体-包被原组合的筛选及反应条件优化基础上,建立了动物组织及尿液中氟苯尼考和甲砜霉素残留同时检测的酶联免疫分析方法。本方法对于氟苯尼考的半数抑制浓度(IC_(50))为1.32 ng/mL,线性检测范围为0.31~5.61 ng/mL,检出限为0.12 ng/mL;对于甲砜霉素的IC_(50)为2.13 ng/mL,线性检测范围为0.41~11.20 ng/mL,检出限为0.15 ng/mL,与氯霉素等多种类似物均无交叉反应,动物组织及尿样中氟苯尼考和甲砜霉素的添加回收率均在77.2%~116.0%之间,相对标准偏差15%,适用于实际样品中氟苯尼考和甲砜霉素的快速筛查检测。     

量子点标记链霉亲和素荧光免疫分析测定雌三醇

以生物素化羊抗兔免疫球蛋白和量子点标记链霉亲和素为荧光探针,采用竞争免疫分析模式,建立了一种灵敏度高、选择性好的检测雌三醇的荧光免疫分析方法.对几种测量参数如温育时间和温度、缓冲溶液pH、试剂浓度等进行了优化;方法的线性范围为0.01～1000ng/mL,检出限0.0029 ng/mL,血清样品加标回收率在91%～117%之间.     

甲基紫与苋菜红相互作用的双波长共振光散射比率光谱研究及其分析应用

应用双波长共振光散射比率法(DW-RLS)研究了甲基紫与苋菜红之间的相互作用.在pH 1.24的乙酸钠-HCl缓冲溶液中,甲基紫和苋菜红本身的共振光散射(RLS)信号均很弱,但是当它们相互作用形成缔合物时,导致RLS信号明显增强并出现新的RLS光谱,适当浓度的Triton X-100存在使结合反应敏化,缔合物最大散射峰位于528 nm,RLS信号强度与苋菜红的浓度呈线性关系.通过测量528 nm处的RLS强度或两个波长处RLS强度比值(I417/I343),可对苋菜红进行定量检测.当溶液中甲基紫的浓度为1.54×10-5 mol/L时,RLS法测定苋菜红的线性范围和检出限分别为0.05～0.50 μg/mL和0.02 μg/mL,而DW-RLS法的线性范围和检出限分别为0.01～0.60 μg/mL和1 ng/mL,与RLS法相比较,DW-RLS法受酸度、离子强度等环境条件影响较小,并且有更宽的线性范围和更低的检出限.     

基于非标记核酸适配体荧光法检测灌溉水中汞离子的研究

该文利用汞特异性核酸适配体和可以嵌入双螺旋脱氧核糖核酸中的荧光染料PicoGreen建立了一种快速检测汞离子的荧光分析方法.通过荧光信号强度来测定汞离子浓度,并获得了汞离子浓度的对数和荧光强度之间的线性关系.方法的线性范围为0.001～100g/mL,检出限达到0.38 ng/mL.在As3+、Pb2+、Cd2+、C...     

应用水相合成的CdTePCdS核壳型量子点荧光探针测定DNA

以巯基丙酸（HS-CH2CH2COOH）为稳定剂水相合成了核壳型CdTePCdS量子点（QDs）。CdTePCdSQDs具有宽而连续的激发光谱和狭窄对称的发射光谱,最大发射波长位于578nm。与DNA作用后荧光强度显著降低。基于DNA对量子点荧光的猝灭效应,将CdTePCdS量子点作为荧光探针建立了一种简便快速测定DNA的荧光分析法,详细研究了pH、量子点浓度、离子强度、温度等备件对量子点荧光及DNA测定的影响。该方法测定ctDNA线性范围为50．0—750．0ng／mL,检出限为20ng／mL．7次重复测定O．5ttg／mLctDNA的相对标准偏差为2．0％。方法可用于合成样品的测定。     

Cationic cyanine as a near-infrared fluorescent probe for the determination of nucleic acids

A new method with a cationic near-IR cyanine as fluorescent probe was developed for the determination of nucleic acids. The near-IR cyanine shows maximum excitation and emission wavelengths at 765 and 790 nm, respectively, in aqueous solution. The method is based on the fluorescence decrease of near-IR cyanine in the presence of nucleic acids. Under optimal conditions, the ratio of fluorescence intensity in the absence and presence of nucleic acids was proportional to the concentration of nucleic acids over the range 0.10-1.2 microg/mL for CT (calf thymus) DNA or SM (salmon sperm) DNA, and 0.10-1.6 microg/mL for yeast RNA. The detection limits were 30 ng/mL for CT DNA, 25 ng/mL for SM DNA and 70 ng/mL for yeast RNA. The relative standard deviation (n = 6) was 2.1% for 500 ng/mL CT DNA, 2.4% for 500 ng/mL SM DNA and 2.7% for 500 ng/mL yeast RNA, respectively.     

Factors influencing the detection limit of the lateral-flow sandwich immunoassay: a case study with potato virus X

Key factors influencing the analyte detection limit of the sandwich immunochromatographic assay (ICA), namely, the size of gold nanoparticles, the antibody concentration, the conjugation pH, and characteristics of membranes, are discussed. The impacts of these factors were quantitatively characterized and compared for the first time using the same antigen (potato virus X). The antibody-colloidal gold conjugates synthesized at pH 9.0-9.5 (the pH was examined in the range from 7.5 to 10.0) and at an antibody concentration of 15 μg/mL (the concentration was tested from 10 to 100 μg/mL) demonstrated maximum binding with the analyte. The relationship between the size of gold nanoparticles and the ICA detection limit was determined. The detection limit decreases from 80 to 3 ng/mL (for antibodies with K (D) = 1.0 × 10(-9) M, data were obtained using a BIAcore X instrument) for a series of particles with a diameter from 6.4 to 33.4 nm (electron microscopy and dynamic light scattering data). In the case of larger particles (52 nm in diameter), the detection limit increases and reaches 9 ng/mL. A 10 mM phosphate buffer, pH 8, and a 50 mM phosphate buffer, pH 7, were the conditions of choice for the deposition of reactants. Taking into account these facts, we developed a lateral-flow test system for the rapid (10 min) detection of potato virus X in plant leaves. The ICA provided a visual detection limit of 3 ng/mL. In the case of the instrumental processing, potato virus X can be determined in the concentration range from 3 to 300 ng/mL with a detection limit 2 ng/mL.     

Cationic cyanine as a near-infrared fluorescent probe for the determination of nucleic acids

A new method with a cationic near-IR cyanine as fluorescent probe was developed for the determination of nucleic acids. The near-IR cyanine shows maximum excitation and emission wavelengths at 765 and 790 nm, respectively, in aqueous solution. The method is based on the fluorescence decrease of near-IR cyanine in the presence of nucleic acids. Under optimal conditions, the ratio of fluorescence intensity in the absence and presence of nucleic acids was proportional to the concentration of ¶nucleic acids over the range 0.10–1.2 μg/mL for CT (calf thymus) DNA or SM (salmon sperm) DNA, and 0.10–¶1.6 μg/mL for yeast RNA. The detection limits were ¶30 ng/mL for CT DNA, 25 ng/mL for SM DNA and ¶70 ng/mL for yeast RNA. The relative standard deviation (n = 6) was 2.1% for 500 ng/mL CT DNA, 2.4% for ¶500 ng/mL SM DNA and 2.7% for 500 ng/mL yeast RNA, respectively.     

A novel method for the determination of total protein in human serum by near infrared fluorescence recovery

A novel fluorometric method has been developed for the determination of total protein in human serum with a new near-IR reagent as a fluorescence probe, based on the fluorescence recovery of the cyanine-CTAB system in the presence of protein. Maximum fluorescence is produced with maximum excitation and emission wavelengths at 765 and 812 nm, respectively. Under optimal conditions, the calibration graphs are linear over the ¶range 0.4–12.0 μg/mL for protein. The detection limit is 70 ng/mL, and the relative standard deviation of six replicate measurements is 1.14% for 6.0 μg/mL protein. The results are satisfactory.     

A novel method for the determination of total protein in human serum by near infrared fluorescence recovery

A novel fluorometric method has been developed for the determination of total protein in human serum with a new near-IR reagent as a fluorescence probe, based on the fluorescence recovery of the cyanine-CTAB system in the presence of protein. Maximum fluorescence is produced with maximum excitation and emission wave-lengths at 765 and 812 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-12.0 microg/mL for protein. The detection limit is 70 ng/mL, and the relative standard deviation of six replicate measurements is 1.14% for 6.0 microg/mL protein. The results are satisfactory.     

Highly sensitive determination and validation of gabapentin in pharmaceutical preparations by HPLC with 4-fluoro-7-nitrobenzofurazan derivatization and fluorescence detection

A sensitive HPLC method with pre-column fluorescence derivatization using 4-Fluoro-7-Nitrobenzofurazan (NBD-F) has been developed for the determination of gabapentin in pharmaceutical preparations. The method is based on the derivatization of gabapentin with (NBD-F) in borate buffer of pH 9.5 to yield a yellow, fluorescent product. The HPLC separation was achieved on a Inertsil C(18) column (250 mm × 4.6 mm) using a mobile phase of methanol water (80:20, v/v) solvent system at 1.2 mL/min flow rate. Mexiletine was used as the internal standard. The fluorometric detector was operated at 458 nm (excitation) and 521 nm (emission). The assay was linear over the concentration range of 5 50 ng/mL. The method was validated for specificity, linearity, limit of detection, limit of quantification, precision, accuracy, robustness. Moreover, the method was found to be sensitive with a low limit of detection (0.85 ng/mL) and limit of quantitation (2.55 ng/mL). The results of the developed procedure for gabapentin content in capsules were compared with those by the official method (USP 32). Statistical analysis by t- and F-tests, showed no significant difference at 95 confidence level between the two proposed methods.     

Determination of idebenone in plasma by HPLC with post-column fluorescence derivatization using 2-cyanoacetamide

Idebenone is a benzoquinone analog that is used in the treatment of several neurological disorders including Friedreich's ataxia. It was found that the reaction of idebenone with 2-cyanoacetamide under alkaline conditions generates fluorescent products, and the reaction was considered to proceed via Craven's reaction. The reaction mixture from idebenone gave fluorescence with excitation and emission maximum wavelengths at 358 nm and 409 nm, respectively. It was adopted for HPLC with post-column fluorescence derivatization of idebenone. Idebenone in the plasma showed a linear response in the range of 0.5-32 ng (25-1600 ng/mL), and the quantitation limit (S/N=10) was 12.5 ng/mL. The detection limit (S/N=3) of the standard solution of idebenone was 0.1 ng. The HPLC system was applied to the human blood plasma obtained by finger prick. The plasma sample obtained by finger prick gave a similar chromatogram to that of venous blood obtained by venipuncture.     

Determination of tianeptine in tablets by high-performance liquid chromatography with fluorescence detection

A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-CI). A mobile phase consisting of acetonitrile-10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45-300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were <0.46 and <0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.     

铝试剂的荧光光谱与荧光量子产率

首次研究了铝试剂的荧光光谱和荧光量子产率,发现pH3至pH12条件下,用紫外光照射铝试剂溶液可以产生荧光,最大激发波长和最大发射波长分别为297nm和409nm,荧光强度与铝试剂浓度之间存在良好的线性关系,线性范围为0.01～3μg/mL,检测下限为0.01μg/mL,以硫酸奎宁为参比,测得铝试剂的荧光量子产率为0.16。