Detection of minute chemical species by principal-component analysis.
Detection of minute chemical species by principal-component analysis.
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通过主成分分析检测微小化学物质。
DOI：
10.1021/ac981430z
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发表时间：
1999
影响因子：
7.4
通讯作者：
T. Hasegawa
中科院分区：
文献类型：
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作者：
T. Hasegawa
提出了一种基于主成分分析（PCA）检测混合光谱中微小谱带的新分析方法。这一新的PCA方法表明，当组分的重叠度变化很大时，可以在没有组分先验知识的情况下分离出重叠的组分光谱。该技术可用于微量化学物质的检测。这一概念得到了计算机模拟的证实。在模拟中，成功地获得了抽象谱（加载向量），并且通过计算其分数，也成功地半定量地跟踪了组分的变化。将主成分分析（PCA）方法应用于红外反射-吸收（RA）光谱分析，研究了烷基氘代二棕榈酰磷脂酰胆碱（DPPC-d（62））单分子膜与蔗糖的分子相互作用机理。样品是在蔗糖溶液上制备的DPPC-d（62）单层的Langmuir-Blodgett（LB）膜。LB膜由以下相组成：空气/DPPC-d（62）+蔗糖/蔗糖/基底（金）。主成分分析成功地分离了“DPPC-d（62）+蔗糖”相和“蔗糖”相对应的抽象光谱，并根据分数半定量地计算了蔗糖在各相中的吸光度变化。用石英晶体微天平（QCM）实验证实了吸光度的变化。此外，从抽象光谱中很容易检测到干燥后残留在LB膜中的微小水分子，发现它们的结合位点是DPPC-d的头基中的磷脂部分（62）。
A novel analytical technique based on the detection of minute bands in a mixture spectrum with the use of principal-component analysis (PCA) is presented. This new aspect of PCA indicates that overlapped spectra of some components can be separated with no a priori knowledge of the components when the absorbances of the components vary greatly. This technique can be used for the detection of minute chemical species. The concept was confirmed by computer simulations. In the simulations, abstract spectra (loading vectors) were successfully obtained, and the changes of the component absorbances were also successfully followed semiquantitatively by calculating their scores. The method developed with PCA was applied to the analysis of infrared reflection-absorption (RA) spectra to study molecular interaction mechanism between alkyl-deuterated dipalmitoylphosphatidylcholine (DPPC-d(62)) monolayer and sucrose. The samples were Langmuir-Blodgett (LB) films of the DPPC-d(62) monolayer that was prepared on a sucrose solution. The LB films consisted of the following phases: air/DPPC-d(62) + sucrose/sucrose/substrate (gold). The abstract spectra corresponding to "DPPC-d(62) + sucrose" and "sucrose" phases were successfully separated by PCA, and the absorbance change of sucrose in each phase was semiquantitatively calculated from the score. The absorbance change was experimentally confirmed with quartz-crystal microbalance (QCM) experiments. In addition, minute water molecules that remained in the LB films after drying were readily detected from an abstract spectrum, and their binding site was found to be the phospholipid moiety in the head group of DPPC-d(62).