偏最小二乘分光光度法同时测定痕量铁、锰、铜、锌、钴和镍

痕量Fe^3 ,Mn^2 ,Cu^2 ,Zn^2 ,Co^2 ,Ni^2 与2－（5－溴－2－吡啶偶氮）－5－二乙氨基苯酚（5－Br-PADAP)和溴化十六烷基三甲基铵（CTMAB）在PH8．3时发生高灵敏显色反应，所形成的三元胶束络合的吸收光谱严重重叠，采用偏最小二乘法（PLS）辅助分光光度法测定了合成试样及饲料中上述6种痕量组分，结果表明，PLS法是化学计量学中一种可适用于基体较复杂的实际试样中痕量组分分光度同时测定的多元计算方法。     

偏最小二乘法辅助分光光度法同时测定痕量锰,铁铜和锌

痕量Ｍｎ（Ⅱ），Ｆｅ（Ⅲ），Ｃｕ（Ⅱ）和Ｚｎ（Ⅱ）与２－（５－溴－２－吡啶偶氮）－５－二乙氨基苯酚和聚乙二醉辛基苯基醚在ｐｈ８．８发生高灵敏的显色反应，所形成的三元胶束络合物的吸收光谱严重重叠，用偏最小二乘法（ＰＬＳ）辅助分光光度法成功地同时测定了模拟试样及铝合金和饲料添加剂中上述四各痕量组分，结果表明，ＰＬＳ法是化学计量学法中一种可适用于式体较复杂的实际试样中痕量组分同时分光光度测定的优良的多元     

同时测定铜、镍、锌的非线性偏最小二乘分光光度法

建立了以1－[5-溴－2吡啶偶氮]－2,7－萘二酚（5－Br-PADN)为显色剂,TritonX-100为增溶增敏剂,用非线性偏最小二乘（NLPLS）－分光光度法同时测定Cu^ 、Ni^2 、Zn^2 的方法。用迭代偏最小二乘法（IPLS）选择测定波长,用自编原MATLAB计算机程序进行处理。结果表明,该法不仅克服了三组分之间相互干扰,而且较好地解决了非线性问题,所拟方法用人工样品的分析,准确度较好,结果令人满意。     

主成分-偏最小二乘分光光度法同时测定饲料中的痕量铁、锰、铜、锌

痕量Fe^3＋、Mn^2＋、Cu^2＋、Zn^2＋与2-（5-溴-2-吡啶偶氮）．5-二乙氨基苯酚（5-Br-PADAP）和对．（1,1,3,3．四甲基丁基）苯基醚（Triton X-100）在pH8．3发生高灵敏显色反应,所形成的三元胶束络合物的吸收光谱严重重叠。本文采用主成分-偏最小二乘法（PC—PLS）辅助分光光度法成功地测定了合成试样及饲料中上述4种痕量组分。结果表明,PC—PLS法是化学计量学法中一种可适用于基体较复杂的实际试样中痕量组分同时分光光度测定的优良的多元计算方法。     

偏最小二乘光度法同时测定铜和铁的研究及应用

７－（１－苯偶氮）－８－羟基喹啉－５－磺酸钠在ＰＨ＝４．７５ＨＡｃ－ＮａＡｃ缓冲溶液中能与Ｃｕ（Ⅱ）和ＦＥ（Ⅲ）形成稳定的络合物，本文研究了Ｃｕ（Ⅱ）－ＰＡＨＱＳ、Ｆｅ（Ⅲ）－ＰＡＨＱＳ体系的显色条件，以偏最小二乘法处理两者重叠吸收峰，建立了光度法同时测定铜和铁的方法。     

PLS—分光光度法同时测定铜锌锰

偏最小二乘法(PLS)是用于多组份混合体系同时测定的十分有效的统计学方法。本文将PLS法与光度分析相结合,以5Br-PADAP为显色体系同时计算测定了铜、锌、锰,并应用于铸铝样品的分析,都获得了较满意的结果。还用不相容因子(DF)自检分析结果的可靠性。     

偏最小二乘-分光光度法同时测定钢样中铬、锰

在石亢_磷混合酸介质中,钢铁样品中铬和锰在银离子存在下用过硫酸铵溶液分别氧化至六价和七价,用分光光度法同时测定样品中铬和锰的含量.在380～600 nm波长范围,每间隔10 nm测定一次吸光度.借计算机及Matlab语言编写程序,对所得吸光度数据用偏最小二乘计算法处理并获得结果.     

偏最小二乘-分光光度法同时测定福美锌和代森锰农药残留量

利用紫外可见分光光度法研究了农药福美锌和代森锰与苯基荧光酮的相互作用,发现反应后的产物分别在波长为551和554 nm处最大有吸收,但光谱严重重叠.实验采集了450～700 nm波长范围吸光度数据,并对该数据进行一阶求导后用偏最小二乘法处理,据此建立了偏最小二乘-分光光度法同时测定福美锌和代森锰两种农药的新方法.福美锌和代森锰的线性范围分别为0.3～6.0和0.2～3.5 μg/mL;检出限分别为0.22和0.13 μg/mL.混合样品分析无需分离,方法简单、快速.用于水果、大米和自来水等实际样品测定.     

吸光光度法同时测定施尔康药物中痕量锌铁铜和锰

在pH8.5时,Zn(Ⅱ)、Fe(Ⅲ)、Cu(Ⅱ)和Mn(Ⅱ)均与2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚和非离子表面活性剂聚乙二醇辛基苯基醚发生高灵敏的显色反应,生成稳定的三元胶束络合物,其λmax分别为558,556,560和567nm,表明吸收光谱严重重叠;在相应λmax处,其表观摩尔吸光系数分别为1.04×105,7.32×104,1.02×105和1.13×105L·mol-1·cm-1。用偏最小二乘法和迭代目标转换因子分析法等化学计量学法辅助吸光光度法,不经分离,同时测定了模拟样和施尔康药物试样中痕量锌、铁、铜和锰。虽然体系的加和性较差,但由于两种算法的优良性能,仍取得满意的结果。     

同时测定粮谷中痕量锰铁铜锌的人工神经网络辅助分光光度法

在pH 9.5时,Mn(Ⅱ )、 Fe(Ⅲ )、 Cu(Ⅱ )和 Zn(Ⅱ )均与 2-(5-溴-2-吡啶偶氮 )-5-二乙氨基苯酚和非离子表面活性剂聚乙二醇辛基苯基醚发生高灵敏的显色反应,生成稳定的三元胶束络合物 ,其λ max分别为 566、 560、 562和 559 nm,表明吸收光谱严重重叠 ; 在相应λ max处,其表观摩尔吸光系数分别为 1.13× 105、 7.32× 104、 1.02× 105和 1.04× 105 L· mol－ 1· cm－ 1。用模拟退火－误差反向传播人工神经网络辅助分光光度法,不经分离,同时测定了模拟样和粮谷样中的痕量锰、铁、铜和锌。详细研究了该算法的最佳计算条件。虽然体系的加和性较差,但由于该算法的优良性能,仍然取得了满意结果。     

火焰原子吸收光谱法连续测定香蕉中的铜铁锌锰

研究了香蕉中的金属元素的含量和火焰原子吸收光谱法在同一体系中测定香蕉中微量元素铜、铁、锌、锰的方法，考察了硝酸、过氧化氢的不同用量以及消化时间长短的影响和在同一体系中铜、铁、锌、锰的相互干扰情况。在选定条件下铜检测限为0．064μg／mL，铁为0．275μg／mL，锌为0．157μg／mL，锰为0．187μg／mL，相对标准偏差为1．9％-4．7％，回收率为92．3％-105．0％。     

Rapid Determination of Cotton Content in Textiles by Near-Infrared Spectroscopy and Interval Partial Least Squares

Textile products must be marked by fabric type and composition on the label and cotton is by far the most important fiber in the industry and often needs fast quantitative analysis. The corresponding standard methods are very time-consuming and labor-intensive. The work focuses on exploring the feasibility of combining near-infrared (NIR) spectroscopy and interval-based partial least squares (iPLS) for determining cotton content in textiles. Three types of partial least square (PLS)-based algorithms were used for experimental measurements. A total of 91 cloth samples with cotton content ranging from 0 to 100% (w/w) were collected and all compositions are commercially available on the market in China. In all cases, the original spectrum axis was split into 20 subintervals. As a result, three final models, i.e., the iPLS model on a single subinterval, the backward interval partial least squares (biPLS) model on the region remaining six subintervals, and the moving window partial least squares (mwPLS) model with a window of 75 variables, achieved better results than the full-spectrum PLS model. Also, no obvious differences in performance were observed for the three models. Thus, either iPLS or mwPLS was preferred considering their simplicity, which suggested that iPLS and mwPLS combined with NIR technique may have potential for the rapid determination of the cotton content of textile products with comparable accuracy to standard procedures. In addition, this approach may have commercial and regulatory advantages that avoid labor-intensive and time-consuming chemical analysis.     

Flow-Injection Simultaneous Chemiluminescence Determination of Ascorbic Acid and L-Cysteine with Partial Least Squares Calibration

In this paper, a flow-injection chemiluminescence system is proposed for simultaneous determination of ascorbic acid and L-cysteine with partial least squares calibration. This method is based on the fact that both AA and Cys can quantitatively reduce Fe³⁺ to Fe²⁺, and that the reaction rates of AA and Cys with Fe³⁺ are different. The reduced product Fe²⁺ was detected with the luminol-Fe²⁺–O₂ CL system. The CL intensity was measured and recorded at different reaction times of Fe³⁺ with AA and Cys, and the obtained data was processed by the chemometric approach of partial least squares. The experimental calibration set was composed of 16 sample solutions using an orthogonal calibration design for two component mixtures. The calibration curve was linear over the concentration range of 0.066µgmL^–1 and 0.440µgmL^–1 for ascorbic acid and L-cysteine, respectively. The proposed method was successfully applied to the simultaneous determination of both analytes in pharmaceutical formulations and human urine samples.     

加权最小二乘光度法同时测定钨和钼

痕量钨和钼与芦丁在混合表面活生剂（ＣＴＭＡＢ＋Ｂｒｉｊ－３５）存在下，于ｐＨ５．４ＨＡＣ－ＮａＡｃ介质中产生灵敏的显色反应，所形成的胶束配合物的吸收峰严重重叠。用加权最小二乘法成功地同时测定了混合样中的两组分。     

Near-Infrared Spectroscopy Analytical Model Using Ensemble Partial Least Squares Regression

A novel ensemble-based feature selection method was developed which is designated as ensemble partial least squares regression coeffientents (EPRC). It was composed of two steps: generating a series of different single feature selectors and aggregating them to reach a consensus. Specifically, the bootstrap resampling approach was used to generate a diversity of single feature selectors, and the absolute values of the regression coefficients of the partial least squares (PLS) model were used to rank the features. Next, these feature rankings out of single feature selectors were aggregated by the weighted-sum approach. Finally, coupled with the regression model, the features selected by EPRC were evaluated through cross validation and an independent test set. By experiments of constructing the spectroscopy analysis model on three near infrared spectroscopy (NIRS) datasets, it was shown that the EPRC located key wavelengths, gave a promotion to regression performance, and was more stable and interpretable to the domain experts.