同步荧光法同时测定溶解态的菲与2-乙基菲

将同步荧光法结合人工神经网络(ANN)和支持向量回归(SVR)用于混合体系中荧光光谱重叠的菲(Phe)和2-乙基菲(2-EP)两组分的同时测定。通过三维同步荧光法结合平行因子(PARAFAC)分析寻得Phe和2-EP的特征波长差Δλ为118 nm。在220~280 nm范围内,以31个波长处荧光强度值作为模型的输入变量用于建立ANN和SVR模型。结果显示,ANN模型分析Phe和2-EP预测样本的回收率分别为92.5%~104.9%和96.1%~104.3%,预测均方根误差(RMSEP)分别为2.08和2.95;SVR模型分析预测样本的回收率分别为98.2%~101.3%和94.9%~104.2%,RMSEP分别为0.74和2.42。实际水样的加标回收实验显示,基体简单的矿泉水中两种模型均取得满意结果;而基体复杂的湖水中样品预测值较实际值低,且SVR模型比ANN的预测性能更加稳健,泛化能力更强。将同步荧光法结合SVR模型应用于Phe和2-EP单独及混合状态下与腐植酸(HA)相互作用的研究,结果显示混合体系中Phe和2-EP与HA的结合系数均小于各自单组分体系,表明Phe和2-EP之间存在竞争吸附。     

二阶导数同步荧光光谱法同时直接测定厚朴酚及和厚朴酚

研究了厚朴酚与和厚朴酚及其混合溶液的二阶导数同步荧光光谱,结果两者的二阶导数同步荧光光谱得到完全分离,消除了彼此间的干扰,据此建立了一种二阶导数同步荧光光谱法同时直接测定混合物中厚朴酚与和厚朴酚的新方法.厚朴酚与和厚朴酚的线性范围分别为2.8～500.0 μg/L和4.3～560.0 μg/L;检出限分别为0.84和1.30 μg/L,回收率分别为94.65%～105.58%和95.09%～104.51%; 相对标准偏差均低于4.08%.本方法用于同时直接测定厚朴药材及其提取物中厚朴酚与和厚朴酚含量,结果令人满意.     

基于SSPA-同步荧光法的鸭蛋蛋清中强力霉素残留含量的检测研究

应用同步荧光光谱技术结合分段连续投影算法(SSPA)实现了对鸭蛋蛋清中强力霉素含量的快速检测。首先对蛋清、强力霉素标准品和含有强力霉素的蛋清进行三维同步荧光光谱分析,确定了其最佳波长差(△λ)为110 nm;然后对60个含有强力霉素的蛋清样本进行同步荧光光谱扫描,运用SSPA分别从全光谱和划分不同子区间中提取特征波长,作为多线性回归(MLR)、偏最小二乘法(PLS)、主成分回归(PCR)的输入变量,分别建立了SSPA-MLR、SSPA-PLS和SSPA-PCR模型。结果表明,利用SSPA法可以压缩模型的输入变量,缩减率为90.8%。划分为6个光谱子区间的SSPA-MLR模型的预测结果最好,其预测集样本的决定系数(R2)和预测均方根误差(RMSEP)分别为0.9896和0.89,有效地提高了模型的效率和预测能力。该方法为快速检测鸭蛋蛋清中抗生素提供新的方法。     

导数同步荧光光谱-小波-SGA-LSSVR联用快速测定鸭蛋蛋清中新霉素残留含量

新霉素在巯基乙醇存在的条件下与邻苯二甲醛生成的衍生物具有强荧光特性,可实现鸭蛋蛋清中新霉素残留含量的荧光测定。在模型建立过程中,分析了波长为280～390 nm光谱范围内的三维同步荧光光谱,确定检测鸭蛋蛋清中的新霉素含量的最佳波长差Δλ为110 nm;然后利用db10小波的2层分解对一阶导数同步荧光光谱进行去噪处理,并利用分段遗传算法(SGA)优选出了14个特征波长;最后应用最小二乘支持向量回归(LSSVR)建立了鸭蛋蛋清中的新霉素含量的预测模型,其模型预测集的决定系数(R2)和预测均方根误差(RMSEP)分别为0.9671和1.713。结果表明,SGA能有效提取出鸭蛋蛋清中新霉素对应的特征波长,有利于提高LSSVR模型预测精度,可实现鸭蛋蛋清中新霉素残留含量的快速测定。     

紫外光谱法对维生素E油酸酯、维生素E与油酸的同时测定

建立了混合体系中维生素E、油酸和维生素E油酸酯同时测定的方法,用光纤光谱仪获取混合体系紫外-可见透射光谱.实验按均匀设计建立校正集和预测集,在255 ～315 nm波段采用偏最小二乘法建立了同时定量测定该3组分的校正模型,并用间隔区间偏最小二乘法(iPLS)通过优选建模区间改进油酸的预测模型.采用iPLS能够显著提高模型准确度,尤其对光谱弱响应的物质,最大相对误差从PLS直接建模的54.7%降至iPLS的8.98%,建立的模型可满足动力学研究的原位分析需要.     

支持向量回归-同步荧光光谱法预测鸭肉中克百威残留

为了满足鸭肉中克百威残留分析及快速检测的要求,基于克百威水解物在巯基乙醇存在的条件下能与邻苯二甲醛反应产生具有强荧光性衍生物的方法,建立了应用同步荧光光谱法测定鸭肉中克百威残留量的预测模型。对含有克百威鸭肉样品的三维同步荧光光谱进行分析,确定其最佳波长差Δλ为120 nm;利用遗传算法(GA)结合交互验证均方根误差(RMSECV)从240～450 nm光谱中筛选出19个波长作为定量分析模型的输入特征变量;对SVR、PCR、PLS 3种回归模型的性能进行比较,实验发现SVR模型的预测结果最好,其预测集的决定系数(r2)和预测均方根误差(RMSEP)分别为0.999 4和0.878 7。研究结果表明,采用同步荧光光谱法结合支持向量回归算法测定鸭肉中克百威的残留量,具有快速、预测精度高等特点,可为检测鸭肉中的克百威残留量提供一种可行的方法。     

一种缩氨基硫脲类衍生物探针测定生物样品中的蛋白质含量

在Tris-HCl缓冲溶液体系中(pH=7.4),研究了1,4-二羟基-2-甲酰基-9,10-蒽醌缩对甲氧基苯基氨基硫脲(EN)与人血清白蛋白(HSA)体系的荧光猝灭光谱和三维荧光光谱,证明EN与HSA可以发生相互作用,使人血清白蛋白的疏水微环境的极性以及构象发生变化。 考察了Δλ值、反应介质和离子强度等因素对体系同步荧光光谱特征及强度的影响。 在此基础上,建立了以EN为分子探针,运用固定波长同步荧光光谱法测定生物样品中的蛋白质含量的方法。 在最佳实验条件下,体系同步荧光强度与HSA在1.380~165.6 mg/L范围内呈良好的线性关系。 对11份空白溶液进行平行测定,检出限达到0.414 mg/L,相对标准偏差为1.52%。 运用此方法对血清、唾液、尿液进行了加标回收实验,回收率在98.4%～105%。 且同步荧光光谱法测定结果与考马斯亮蓝法基本一致。     

近红外光谱混合模型定量分析不同物理状态样品的研究

近红外光谱(NIRS)以漫反射模式对非均质样本进行测量时,由于其光谱散射和吸收系数差异较大,建立的校正模型准确性和稳健性较低,因此,本研究提出了一种基于均质样本和模型转移方法建立混合模型的策略,解决非均质样本近红外光谱检测的问题.以烟叶样本为研究对象,分别建立了基于Shenk专利算法(Shenk′s)、分段直接标准化(PDS)和基于典型相关分析的模型转移算法(CTCCA)的烟粉+烟丝、烟粉+烟片混合模型,用于烟丝和烟片样本中烟碱含量的预测.结果表明,混合模型对烟丝和烟片样本的预测均方误差(RMSEP)较直接建模分别降低了1.39%和2.73%,预测结果有一定的改善,稳健性提高,3种方法中CTCCA表现最优.因此,采用近红外光谱均质模型和模型转移方法建立的混合模型对非均质样本的测定具有可行性,有利于在线近红外光谱分析技术的发展,可为近红外光谱模型的共享提供参考.     

磺胺嘧啶钠探针分析生物样品中蛋白质含量的研究

在pH 7.4的Tris-HCl缓冲溶液中,荧光猝灭光谱和三维荧光光谱显示磺胺嘧啶钠(SDS)可与人血清白蛋白(HSA)相互作用,使人血清白蛋白疏水微环境极性以及构象发生变化。考察了Δλ值、反应介质、离子强度等因素对该体系同步荧光光谱特征及强度的影响。在选定的最佳实验条件下,体系的同步荧光强度(ISF)与人血清白蛋白在1.38～276μg/mL的浓度范围内呈现良好的线性关系,线性相关系数为0.9992,从而建立了以磺胺嘧啶钠为分子探针,用固定波长同步荧光光谱分析测定蛋白质的新方法,检测限可达0.48μg/mL。用此方法对生物样品人血清、唾液和尿液中蛋白质含量进行了测定并进行加标回收实验,回收率在95.7%～103.7%之间。本文还用经典的考马斯亮蓝法对样品进行了测定,所得结果和本方法一致。同时还考察了一些常见的共存物质对蛋白质测定的影响。     

8-溴鸟苷探针测定生物样品中蛋白质含量的光谱法研究

研究了8-溴鸟苷(BG)与人血清白蛋白(HSA)体系的荧光猝灭光谱、三维荧光光谱,证明了两者可以发生相互作用,导致人血清白蛋白疏水微环境极性的改变和构象的变化;还分析了△λ值、pH值、离子强度等因素对该体系同步荧光强度的影响,选定了8-溴鸟苷测定生物样品中蛋白质含量的最佳实验条件;在最佳实验条件下,体系的同步荧光强度与...     

Possibility to Biotransform Anthracyclines by Peroxidases Produced by Bjerkandera adusta CCBAS 930 with Reduction of Geno- and Cytotoxicity and Pro-Oxidative Activity

The aim of this study was to evaluate the bioremoval mechanism of anthracycline antibiotics by the white-rot fungus B. adusta CCBAS 930. The activity of oxidoreductases and levels of phenolic compounds and free radicals were determined during the biotransformation of anthraquinone antibiotics: daunomycin (DNR) and doxorubicin (DOX) by B. adusta strain CCBAS 930. Moreover, phytotoxicity (Lepidium sativum L.), ecotoxicity (Vibrio fischeri), genotoxicity and cytotoxicity of anthraquinone dyes were evaluated before and after biological treatment. More than 80% and 90% of DNR and DOX were removed by biodegradation (decolorization). Initial solutions of DNR and DOX were characterized by eco-, phyto-, geno- and cytotoxicity. Despite efficient decolorization, secondary metabolites, toxic to bacteria, formed during biotransformation of anthracycline antibiotics in B. adusta CCBAS 930 cultures. DNR and DOX metabolites did not increase reactive oxygen species (ROS) production in human fibroblasts and resazurin reduction. DNR metabolites did not change caspase-3 activity.     

胶束溶液中同步荧光法测定苯并［a］芘的研究

在不同胶束溶液中考察了苯并［ａ］芘（Ｂ［ａ］Ｐ）的同步荧光光谱。结果表明，在十二烷基苯磺酸钠（ＳＤＢＳ）胶束溶液中，Ｂ［ａ］Ｐ的检测限可达０．００９３ｎｇ／ｍＬ，方法相对标准偏差为１．７％。用于实际水样的测定，结果满意。     

恒波长同步荧光光谱法测定人体尿液中氯波必利的研究

研究发现甲醛溶液可使氯波必利的荧光强度显著增强.在pH为6.6的Britton-Robinson(B-R)缓冲介质中,以恒波长差Δλ=30 nm进行同步荧光扫描,可消除人体尿液中内源性荧光物质的背景干扰,其同步特征峰的强度与氯波必利的质量浓度呈线性关系,据此建立了直接测定尿样中氯波必利的恒波长同步荧光分析方法,并对测定...     

Non-aqueous fluorimetric determination of scandium in silicate rocks

A method for the fluorimetric determination of scandium with 1,2,7-trihydroxyanthraquinone in dimethylformamide medium is described. The calibration graphs obtained by the normal, synchronous, and synchronous first and second derivative techniques are linear between 12 and 225 ng/ml, and the detection limit is 2 ng/ml. The method is applied to the determination of Sc(III) in two simulated and two naturally occurring rocks.     

傅里叶变换红外光谱法应用于水-乙醇溶液中海南霉素的测定

随着化学计量学方法处理光谱重叠和光谱采样技术的发展,红外光谱应用于多组份同时定量分析和过程分析的研究日益受到人们的关注^[1～5].海南霉素(C₄₇H₇₉O₁₅Na,分子量907.122)是国家一类新药,用于防治鸡球虫病,易溶于有机溶剂,不溶于水.     

Analytical control of organic additives in electrolytic baths by UV spectroscopy in combination with multivariate analysis

A method for the simultaneous determination of organic additives in Zn(II) and Ni(II) electrolytic baths is proposed. Absorbance and first-derivative spectra were subjected to direct and inverse multiple linear regression (CLS and ILS, respectively) in order to choose the optimum alternative. The use of a factor design to prepare the samples enables the identification of interactions between analytes and their correction by ILS. The results provided by first-derivative spectra were slightly better than those obtained with absorbance spectra (prediction errors were always less than 2% with the former). The ILS procedure was applied to three industrial baths used to a different extent, with highly satisfactory results.     

褶合曲线分析法用于同步荧光光谱法同时测定苯酚和对苯二酚

采用计算机辅助褶合曲线分析法结合同步荧光光谱法对双组分体系（苯酚／对苯二酚、苯酚／邻苯二酚）同时测定。苯酚和对苯二酚的荧光光谱重叠比较严重，同步荧光光谱虽使选择性有所改善，但仍有重叠，苯酚和对苯二酚的同步荧光峰相差仅２０ｎｍ。褶合曲线分析法可很好地用来测定苯酚和对苯二酚，方法简便、准确、易于自动化，同时证明，褶合曲线分析法在荧光分析方面具有很好的应用前景。进一步试验苯酚和邻苯二酚双组分的同时测定，苯酚和邻苯二酚的同步荧光峰相差仅１０ｎｍ，结果表明，该法虽然能在苯酚存在的情况下测定邻苯二酚，但不能同时测定苯酚。     

A flow-through fluorimetric sensing device for determination of alpha- and beta-naphthol mixtures using a partial least-squares multivariate calibration approach

A single flow-through optosensor spectrofluorimetric system is proposed for the resolution of mixtures of alpha- and beta-naphthol at mug l(-1) levels using a partial least-squares (PLS) calibration approach. The sensor was developed in conjunction with a monochannel flow-injection analysis system with fluorimetric detection using Sephadex QAE A-25 resin as an active sorbent substrate in the flow cell and the second derivative of the native synchronous fluorescence spectra of analytes as analytical signal. In the manifold, the solutions of naphthol (at pH 10.0) were injected in a carrier stream of KCl (0.15 M)/NaOH (10(-2) M). Because of the strong spectral overlap, the mixture could not be resolved by conventional spectrofluorimetry. The non-additive behaviour of the fluorescence signals revealed an interaction in the system, which was not found by working in the solution only (without the sorbent support). This interaction, probably due to the environment of the analytes on the solid phase, made impossible their simultaneous determination. So, the use of synchronous fluorescence spectroscopy or even its derivative signal could not resolve satisfactorily the mixture. The simultaneous determination of both naphthol has been carried out by recording the signal of the second-derivative synchronous fluorescence (Deltalambda=170 nm) spectra between 200 and 450 nm and a PLS multivariate calibration treatment. The optimum number of factors was selected by using the cross-validation method. After validating the proposed method, it was applied to the determination of these compounds in natural waters with different amounts of each chemical.     

Analytical control of organic additives in electrolytic baths by UV spectroscopy in combination with multivariate analysis

A method for the simultaneous determination of organic additives in Zn(II) and Ni(II) electrolytic baths is proposed. Absorbance and first-derivative spectra were subjected to direct and inverse multiple linear regression (CLS and ILS, respectively) in order to choose the optimum alternative. The use of a factor design to prepare the samples enables the identification of interactions between analytes and their correction by ILS. The results provided by first-derivative spectra were slightly better than those obtained with absorbance spectra (prediction errors were always less than 2% with the former). The ILS procedure was applied to three industrial baths used to a different extent, with highly satisfactory results. Received: 15 June 1998 / Revised: 7 September 1998 / Accepted: 15 September 1998     

三维荧光二阶校正法用于未知混合物中苯酚含量的测定

将三维荧光光谱技术与秩消失因子分析、广义秩消失因子分析和交替三线性分解3种二阶校正方法相结合,建立了测定未知混合物中苯酚含量的三维荧光二阶校正新方法。设定在激发波长240~280 nm和发射波长280~360 nm范围内测定未知混合物中苯酚的三维荧光光谱,构建三维响应数据阵,运用基于三线性分解的二阶校正算法进行解析。结果表明,当模拟样品的组分数为2时,秩消失因子分析、广义秩消失因子分析和交替三线性分解3种方法测定苯酚的预测均方根误差分别为0.33,1.18和0.15,平均回收率分别为101.6%,115.6%和101.9%;当组分数为3时,3种方法的预测均方根误差则分别为1.61,1.80和0.51,平均回收率分别为134.2%,133.9%和107.1%;将其分别应用于实际样品中苯酚的测定,结果满意,且交替三线性分解法的测定结果优于秩消失因子分析法和广义秩消失因子分析法。