三维荧光结合二阶校正法测定蛇床子及人体血浆中蛇床子素的含量

利用二阶校正的平行因子分析(PARAFAC)算法,交替三线性(ATLD)算法和自加权交替三线性(SWATLD)算法辅助三维荧光对中药蛇床子和人体血浆中蛇床子素进行了定性及定量分析。中药蛇床子和人体血浆体系中背景复杂,与蛇床子素的荧光峰有严重的重叠。然而,PARAFAC算法,ATLD算法和SWATLD算法具有独特的"二阶优势",即使在有未知干扰存在的情况下也能得到令人满意的结果。三种方法测得的蛇床子素在中药蛇床子中的回收率分别为103.6%,101.5%和103.0%,在血浆中的回收率分别为111.1%,100.0%和106.6%,得到的蛇床子素解析光谱和真实光谱几乎完全重合。实验结果说明,这三种化学计量学二阶校正算法可以在有未知干扰组分共存的情况下对蛇床子素进行准确而有效的定性及定量测定。     

应用二阶校正算法-荧光分光光度法同时测定血浆中诺氟沙星和左氧氟沙星

应用三维荧光技术,结合化学计量学中的二阶校正算法,在诺氟沙星和左氧氟沙星荧光光谱严重重叠,以及干扰物质存在下对血浆中两种喹诺酮类药物进行了同时定量分析。三维荧光激发波长范围265～510nm,发射波长范围300～650 nm。交替不对称三线性分解(AATLD)算法解析得到的诺氟沙星和左氧氟沙星的平均回收率分别为96.9%和103.9%。方法前处理简单、不需预先分离、可以快速定量分析血浆中光谱相互干扰的待测药物的含量。     

多维数据解析联用三维荧光光谱检测污水中酚类污染物残留

应用三维荧光结合化学计量学中的二阶校正方法对城市污水中的苯酚、对苯二酚和邻苯二酚进行了定量分析研究.选用β-环糊精作为荧光增敏剂,三维荧光激发波长范围205～450 nm,发射波长范围215～320 nm.通过自加权交替三线性分解(SWATLD)解析得到的苯酚的平均回收率为95.84±0.41％,对苯二酚的平均回收率为102.31±0.44％,邻苯二酚的平均回收率为100.27±0.43％.该方法前处理简单,不需预先分离,可以快速定量分析污水中光谱相互干扰的多个待测组分的含量.     

三维荧光光谱结合二阶校正算法用于尿液中常见毒品的检测

利用三维荧光光谱技术结合二阶校正算法对尿液中冰毒、3,4-亚甲基二氧基甲基苯丙胺、可卡因和吗啡4种毒品进行快速定量分析.结果表明,平行因子(PARAFAC)、交替三线性分解(ATLD)和自加权交替三线性分解(SWATLD)算法均能很好地分辨出待测组分,且通过PARAFAC与SWATLD算法解析三维光谱数据获得的尿液背景干扰下4种毒品的平均回收率为92.8%~106.1%,相对误差低于8%.三维荧光光谱结合二阶校正算法可用于常见毒品滥用者的快速检测,为缉毒禁毒工作提供新的检测手段.     

三维荧光结合二阶校正法测定绞股蓝中槲皮素含量

采用三维荧光并结合二阶校正的平行因子分析(PARAFAC)算法、交替三线性(ATLD)算法和自加权交替三线性(SWATLD)算法对中药绞股蓝中的槲皮素含量和回收率进行测定,Al(Ⅲ)作敏化剂增加槲皮素的荧光强度。核一致检验法说明体系中荧光组分数为2,其中一个组分对应于槲皮素,另一个对应于中药中的一个共存组分。3种方法测定中药绞股蓝中槲皮素的含量分别为0.274 9%,0.272 9%和0.272 7%,回收率分别为96.3%,103.1%和96.8%,得到的槲皮素解析光谱和真实光谱几乎完全重合。实验结果表明,化学计量学"二阶校正"法具有简单、快速、高效及操作费用低等特点,可用于复杂成分的定性和定量分析。同时,还讨论了中药溶液中内滤光效应对荧光强度及定量分析的影响,并采用数学校正法对中药溶液的内滤光效应进行校正,实验发现测定的荧光强度用相应的溶液吸光度校正后,定量分析结果的准确度大大改善。     

三维荧光二阶校正法同时测定水果样中α-萘乙酸和吲哚-3-乙酸

将三维荧光光谱技术与分别基于交替惩罚三线性分解(APTLD)和平行因子分析(PARAFAC)2种算法的二阶校正方法相结合,实现了水果样中α-萘乙酸(NAA)和吲哚-3-乙酸(IAA)含量的直接快速同时定量测定.对于西瓜提取液,在量测体系选取的组分数为3时,采用APTLD二阶校正法所获得的NAA和IAA的平均回收率分别为...     

激发-发射荧光法同时测定大米中多菌灵和西维因残留量

样品经预处理后使用激发-发射荧光光谱仪获取荧光信号。基于交替惩罚三线性分解（APTLD）和自加权交替三线性分解（SWATLD）算法的二阶校正方法,借助显著的“二阶优势”在重叠的光谱信号中准确分辨出多菌灵和西维因的光谱,获得定性定量结果。多菌灵和西维因的回收率分别为97.4%～105.2%和103.0%～106.2%,标准偏差均小于4%,预测均方根误差（RMSEP）在接受范围内。对选择性、灵敏度、检出限、定量限等品质因子进行了计算,并使用椭圆联合置信区（EJCR）进行统计分析,表明该方法可实现大米中多种农药残留同时定量检测。     

三维荧光光谱结合二阶校正算法测定人体血浆和厚朴药材中的厚朴酚及和厚朴酚

利用三维荧光光谱与化学计量学二阶校正算法相结合, 直接测定人体血浆中和厚朴药材中的厚朴酚及和厚朴酚. 采用平行因子分析(PARAFAC)算法解析所得两种物质的回收率分别为(99.5±2.6)%和(90.2±1.8)%. 采用交替三线性分解(ATLD)算法解析, 当组分数N取3时, 回收率分别为(104.2±3.2)%和(98.7±4.0)%; 当N取4时, 回收率分别为(102.7±2.9)%和(99.0±4.6)%. 同时用该方法对厚朴药材中的厚朴酚及和厚朴酚进行快速定量测定, 结果令人满意. 实验结果表明, 此法可用于复杂试样中未知干扰共存下厚朴酚及和厚朴酚的同时测定.     

三维荧光二阶校正法用于尿液样中氢化可的松的定量测定

本文提出了三维荧光光谱结合二阶校正算法实现人体尿液样中氢化可的松定量测定的新方法。氢化可的松本身的荧光较弱,但与浓硫酸反应后可以生成强荧光的化合物。利用这一特性,采用浓硫酸为氧化剂,设定在激发波长为300-370nm、发射波长为400-580nm范围内测定尿液样中氢化可的松的三维荧光光谱,构建三维响应数据阵,然后运用基于三线性分解的二阶校正算法进行解析。当组分数N取3时,采用基于平行因子分析（PARAFAC）算法的Z-阶校正法的平均回收率为98.6±4.1％,预测残差平方根（RMSEP）为0.0114;采用基于满秩平行因子分析（FRA-PARAFAc）算法的二阶校正法的平均回收率和RMSEP分别为99.3±2.4％和0.0066。两种算法可以得到相近且满意的结果。     

荧光动力学二阶校正法定量分析人血浆样中去甲肾上腺素

提出了荧光动力学结合二阶校正算法实现人血浆样中去甲肾上腺素的间接定量测定新方法. 去甲肾上腺素本身荧光较弱, 在碱性溶液中可以被氧化生成强荧光化合物. 利用这一特性, 在pH值为9.06的硼酸缓冲液作用下采用铁氰化钾为氧化剂、抗坏血酸为抗氧化剂研究这一氧化反应过程. 设定激发波长为390 nm, 在发射波长为439～550 nm的范围内测定一段时间内连续时间点的该动力学反应中间物的荧光光谱, 构建三维响应数据阵, 然后运用三线性分解算法进行解析. 组分数N取3时, 采用基于平行因子分析(PARAFAC)算法的二阶校正法获得的平均回收率(AR)为(102.0±4.1)%, 预测残差平方根(RMSEP)为0.0197; 采用基于满秩平行因子分析(FRA-PARAFAC)算法的二阶校正法获得的平均回收率(AR)和预测残差平方根(RMSEP)分别为(102.4±4.0)%和0.0207. 两种算法可以得到相似且满意的结果.     

Rank annihilation factor analysis for multicomponent kinetic‐spectrophotometric determination using difference spectra

In this work rank annihilation factor analysis (RAFA) is used to analyze difference spectra of kinetic‐spectrophotometric data. Annihilation of the contribution of one chemical component from the original data matrix is a general method in RAFA. However, sometimes RAFA is not suitable for studying rank deficient data such as kinetic‐spectrophotometric measurements. On the other hand, in order to apply RAFA for the determination of an analyte in an unknown sample, a standard two‐way matrix of the analyte with rank one should generally be available. This is not usually attainable for kinetic‐spectrophotometric monitoring of complexation reactions. Processes monitored by difference spectroscopy always have the spectrum of the initial stage subtracted from each spectrum in the data matrix. In this work we show that, for kinetic‐spectrophotometric data of complexation reactions, the spectrum of ligand (reactant) itself can be used as initial spectrum for subtraction. The obtained difference matrix of sample and that of analyte of interest will be full‐rank and rank 1, respectively. Therefore the system can be analyzed by RAFA. The proposed method was investigated with simulated data at the first stage. The method was then applied in the analysis of experimental kinetic‐spectrophotometric data of a complexation reactions of Co(II) and Ni(II) with chromogenic reagent 1‐(2‐pyridylazo) 2‐naphthol in order to do multi‐component determination of these ions in various real samples. Copyright © 2009 John Wiley & Sons, Ltd.     

三维荧光光谱结合二阶校正方法测定细胞培养基中阿霉素的含量

本文采用交替三线性分解(ATLD)和交替归一加权残差三线性分解(ANWE)两种二阶校正方法结合激发发射矩阵荧光光谱对完全不经任何预处理的细胞培养基中的阿霉素进行简单、快速、直接的定量测定.当算法选取组分数为2时,解析得到细胞培养基中阿霉素的平均回收率分别为(100.5±1.8)%和(100.3±1.9)%.在细胞培养基中加入烟酰胺腺嘌呤二核苷酸(NADH)、烟酰胺腺嘌呤二核苷酸磷酸(NADPH)、黄素腺嘌呤二核苷酸(FAD)和黄素单核苷酸(FMN)四种细胞内的自发荧光物后,选取组分数为4时,解析得到细胞培养基中阿霉素的平均回收率分别为(99.1±2.9)%和(99.2±3.1)%.结果表明该分析方法能够准确、快速地直接测定细胞培养基中阿霉素的含量,并且在模拟细胞内荧光干扰环境下可定量测定阿霉素,且能获得令人满意的结果.     

Fluorescence determination of metoprolol in human plasma by trilinear decomposition-based calibration techniques

In this study a new spectrofluorimetric method for the direct determination of metoprolol in human plasma is presented and discussed. It is based on the use of fluorescence excitation–emission matrices (EEMs) and second-order calibration performed with parallel factor analysis (PARAFAC) or alternating trilinear decomposition (ATLD). This methodology enables accurate and reliable discrimination of the analyte signal, even in the presence of unknown and uncalibrated fluorescent component(s), which is often referred to as the second-order advantage. No separation or sample pretreatment steps were required. Satisfactory results were obtained. Metoprolol recoveries in plasma were determined as 87±2% and 90±4% with PARAFAC and ATLD, respectively. All RSD values of intra- and interday assays were below 5%. Figure A three-dimensional plot of EEMs for a plasma sample and metoprolol solution     

Quantitative analysis of levodopa, carbidopa and methyldopa in human plasma samples using HPLC-DAD combined with second-order calibration based on alternating trilinear decomposition algorithm

An HPLC method combined with second-order calibration based on alternating trilinear decomposition (ATLD) algorithm has been developed for the quantitative analysis of levodopa (LVD), carbidopa (CBD) and methyldopa (MTD) in human plasma samples. Prior to the analysis of the analytes by ATLD algorithm, three time regions of chromatograms were selected purposely for each analyte to avoid serious collinearity. Although the spectra of these analytes were similar and interferents coeluted with the analytes studied in biological samples, good recoveries of the analytes could be obtained with HPLC-DAD coupled with second-order calibration based on ATLD algorithm, additional benefits are decreasing times of analysis and less solvent consumption. The average recoveries achieved from ATLD with the factor number of 3 (N = 3) were 100.1 ± 2.1, 96.8 ± 1.7 and 104.2 ± 2.6% for LVD, CBD and MTD, respectively. In addition, elliptical joint confidence region (EJCR) tests as well as figures of merit (FOM) were employed to evaluate the accuracy of the method.     

Interference-free determination of fluoroquinolone antibiotics in plasma by using excitation-emission matrix fluorescence coupled with second-order calibration algorithms

Fluoroquinolones or so-called second-generation quinolones, in particular, ofloxacin (OFL), norfloxacin (NOR), and enoxacin (ENO), with therapeutic advantages possess strongly overlapped fluorescence spectra. In this paper, two strategies were proposed for simultaneous direct determination of OFL, NOR and ENO in plasma by combining fluorescence excitation-emission matrix (EEM) with second-order calibration based on the alternating trilinear decomposition algorithm (ATLD) and parallel factor analysis (PARAFAC). The results showed that both algorithms could solve the problem of serious fluorescence spectral overlapping of the sought-for analytes even in the presence of uncalibrated interferents. However, ATLD has advantages of being insensitive to overestimated component number and fast convergence. The results by using ATLD with an estimated component number of five were reasonably acceptable for clinical analysis. The average recoveries of OFL, NOR and ENO in synthetic samples were 99.7 ± 2.4, 101.5 ± 2.4 and 97.3 ± 3.8%, respectively; the average recoveries of OFL, NOR and ENO in complex plasma were 94.3 ± 2.6, 85.6 ± 3.3 and 103.3 ± 3.0%, respectively.     

Chemometrics-assisted spectrophotometric methods for simultaneous determination and complexation study of Fe(III), Al(III) and V(V) with morin in micellar media

Evolutionary factor analysis (EFA) and rank annihilation factor analysis (RAFA) were applied to resolve the two-way equilibrium spectrophotometric data belonging to the complexes of Fe(III), Al(III) and V(V) with morin (3,5,7,20,40-penta hydroxy flavone) as chelating agent in triton X-100 micellar media. Then, partial least square regression combined with genetic algorithm for wavelength selection (GA-PLS) was used for simultaneous determination of the metal ions. The parameters controlling behavior of the system were investigated and optimum conditions were selected. The predictive abilities of partial least squares regression (PLS) and genetic algorithm-partial least squares regression (GA-PLS) were examined in simultaneous determination of ternary mixtures of metal ions over the concentration range of 17.0-170.0ngml(-1), 25.0-180.0ngml(-1) and 40.0-325.0ngml(-1) for Fe(III), Al(III) and V(V), respectively. The relative standard errors for prediction of the ions in synthetic mixtures were lower than 5% and the mean recoveries in the tap water spiked samples were 104.2 and 101.7% for PLS and GA-PLS, respectively.     

三维荧光二阶校正法用于尿液样和血浆样中左旋多巴的定量测定

本文采用激发发射荧光光谱分别与化学计量学中平行因子分析(PARAFAC)和交替三线性分解(ATLD)二阶校正法相结合,对尿液样和血浆样中左旋多巴含量进行定量测定。实验不需对尿液和血浆预测样进行萃取等分离预处理。在尿液样中,当组分数取2时,用PARAFAC算法和ATLD算法获得的平均回收率分别为(98.9±2.3)%和(99.6±2.8)%。在血浆样中,当组分数取3时,PARAFAC算法和ATLD算法获得的平均回收率分别为(103.1±3.7)%和(99.2±4.2)%。研究结果表明,该法能够解决尿液样和血浆样中左旋多巴因尿液和血浆内源物质与待分析物光谱重叠所引起的难分辨的问题,可用于未知干扰共存下左旋多巴含量的直接快速定量测定。     

Interference-free determination of Sudan dyes in chilli foods using second-order calibration algorithms coupled with HPLC-DAD

This paper presents a new method for the determination of Sudan dyes contained in hot chilli samples. The method employs second-order calibration algorithms to handle the recorded data. The second-order calibration algorithms are based on the popular parallel factor analysis (PARAFAC), alternating trilinear decomposition (ATLD) and self-weighted alternating trilinear decomposition (SWATLD), respectively. These chemometric methodologies have the second-order advantage, which is the ability to get accurate concentration estimates of interested analytes even in the presence of uncalibrated interfering components. The results on a set of spiked chilli test shows that low contents of Sudan I and Sudan II in complex chilli mixtures can be accurately determined using the new method. The sample preparation was based on solvent extraction, and internal standard was not required. Quantification was carried out with simple mobile phase.     

Multivariate standard addition method solved by net analyte signal calculation and rank annihilation factor analysis

This article describes the use of the net analyte signal (NAS) concept and rank annihilation factor analysis (RAFA) for building two different multivariate standard addition models called “SANAS” and “SARAF.” In the former, by the definition of a new subspace, the NAS vector of the analyte of interest in an unknown sample as well as the NAS vectors of samples spiked with various amounts of the standard solutions are calculated and then their Euclidean norms are plotted against the concentration of added standard. In this way, a simple linear standard addition graph similar to that in univariate calibration is obtained, from which the concentration of the analyte in the unknown sample and the analytical figures of merit are readily calculated. In the SARAF method, the concentration of the analyte in the unknown sample is varied iteratively until the contribution of the analyte in the response data matrix is completely annihilated. The proposed methods were evaluated by analyzing simulated absorbance data as well as by the analysis of two indicators in synthetic matrices as experimental data. The resultant predicted concentrations of unknown samples showed that the SANAS and SARAF methods both produced accurate results with relative errors of prediction lower than 5% in most cases.