Chemometrics & Informatics / Ezine
Polycyclic aromatic hydrocarbons: heavy testing
Date: Dec 13, 2011
Author: David Bradley
Complex heavy fuel oil mixtures can be analysed for their polycyclic aromatic hydrocarbon content using multivariate curve resolution and alternating least squares on their chromatographic and mass spectrometric data, according to research published in Analytical Chemistry.
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Journal Highlight: Chemometric analysis of gas chromatographic data - investigation of enological parameters of a bag-in-box white wine as affected by storage time and temperature
Date: Dec 12, 2011
Author:
Score plots from the principal component analysis of gas chromatography data for wine extracts showed grouping trends that were influenced by storage time and temperature. PCA loading plots revealed that changes in chemical profiles were different for wines held at different storage temperatures. Storage time could be predicted accurately by partial least squares regression of the GC data, and, in general, the enological parameters could be predicted accurately from GC fingerprints.
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Journal Highlight: Characterization of a comprehensive flavor database
Date: Nov 17, 2011
Author:
The highly complex and multidimensional nature of flavor perception challenges our ability to both predict and design new flavor entities. Toward this endeavor, classifications of odor descriptors have previously been proposed. In this work, the authors developed a fingerprint-based representation of a large data set collected from many sources over the course of more than 40 years.
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Vendor Column: Reducing System Complexity by Standardizing Laboratory Informatics Solutions
Date: Nov 17, 2011
Author: Chris Stumpf
Welcome to the first in a series of features from Chris Stumpf, a marketing manager at Waters Corporation who focuses on Lab Informatics. Every two months, Chris will publish a new informatics-related article which we hope will build into a worthwhile compendium of informatics material. This month, Chris looks at how a wealth of new standardized informatics solutions are helping the scientist to reduce the drudgery of manual data management in the lab.
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Fat profile: breast cancer biomarkers laid bare
Date: Nov 15, 2011
Author: David Bradley
A multivariate statistical analysis of gas-chromatograph-mass spectrometry data has allowed one team to identify possible biomarkers for breast cancer simply from free fatty acid profiles.
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Journal Highlight: Chemometrics in fuel science: demonstration of the feasibility of chemometrics analyses applied to physicochemical parameters to screen solvent tracers in Brazilian commercial gasoline
Date: Oct 20, 2011
Author:
Commercial gasolines were collected from gas stations located in the Midwestern Sao Paulo State, and analyzed by several physicochemical methods established by ANP Resolution 309. Statistical and exploratory chemometric techniques were employed to discriminate the presence of solvents markers. Results showed that physicochemical parameters such as T10, T90, RON, benzene, saturated and aromatic describe satisfactorily the presence of solvent marker. SIMCA algorithm reveals sensitivity in the training and...
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Calculating spectra: quantum insights into Raman
Date: Oct 15, 2011
Author: David Bradley
The first calculations of Raman optical activity spectra using coupled-cluster theory - one of the most reliable quantum chemical methods available - have been used to provide new insights into the scattering of polarized light from chiral molecules.
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Journal Highlight: Characterisation of Slovenian honeys on the basis of sensory and physicochemical analysis with a chemometric approach
Date: Sep 20, 2011
Author:
The purpose of this study was sensory and physicochemical characterisation of Slovenian honeys with a chemometric approach. Honey samples were obtained from the beekeepers in different natural geographical macroregions of Slovenia. The sensory characteristics of the seven main types of Slovenian honeys are described, together with the physicochemical analyses.
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Algorithmic cancer diagnosis: Raman spectra reveal pre-cancer
Date: Sep 15, 2011
Author: David Bradley
A genetic algorithm can be applied to Raman spectra for the rapid, in vivo identification of pre-cancerous tissues in the cervix, according to work recently published in The Analyst.
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Journal Highlight: OnPLS - a novel multiblock method for the modelling of predictive and orthogonal variation
Date: Aug 30, 2011
Author:
OnPLS is a novel multiblock analysis method that is equivalent to O2PLS in cases with two matrices, but which generalises symmetrically to cases involving more than two matrices. The method's utility was demonstrated by its application to three synthetic data sets. It was shown that OnPLS affords a reduced number of globally predictive components and increased intercorrelations of scores, and that it greatly facilitates interpretation of the predictive model.
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