.... http://www.spectroscopyNOW.com/coi/cda/landing.cda?type=Feature&chId=9 http://www.spectroscopyNOW.com/coi/cma/download.cma?imageType=RssLogo&contentType=Feature&siteId=1&chId=9 http://www.spectroscopynow.com/ http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26644&type=Feature&page=1 Polish scientists have used principal component analysis to help optimize the derivatization of oestrogenic steroids such as estrone and estradiol prior to separation by gas chromatography. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26659&type=Feature&page=1 Welcome to the second in a series of features from Chris Stumpf, a marketing manager at Waters Corporation who focuses on Lab Informatics. Every two months, Chris publishes a new informatics-related article which we hope will build into a worthwhile compendium of informatics material. This month, Chris describes the important concepts to consider when designing a standardized laboratory informatics environment operating in GxP. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26629&type=Feature&page=1 UK scientists have used capillary-scale ion chromatography and suppressed conductivity detection to analyse gunshot residues, sweat and latent fingerprints. The statistical techniques used to extract the data can reveal whether fingerprints were left by someone who fired a gun and even whether or not they smoke. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26506&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26502&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26326&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26404&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26388&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26291&type=Feature&page=1 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 prediction set. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26261&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26165&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26149&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26075&type=Feature&page=1 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. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=26008&type=Feature&page=1 Various approaches to statistical analysis of spectroscopic data can reveal whether red wine has been adulterated with anthocyanins to artificially improve, or "correct", its red colour. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25898&type=Feature&page=1 Predictive power of Stepwise Linear Discriminant Analysis (SLDA) was evaluated to discriminate the behavior of wine fermentation. Information of different chemical concentrations from industrial wine fermentations was used. Procedure consisted of non linear curve fitting and SLDA applied to the parameters of the curve. The correlation coefficient of alcoholic degree, initial concentration of glucose, initial density and correlation coefficient of tartaric acid were the variables more discriminant and they indicated some differences between a normal and abnormal fermentation. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25873&type=Feature&page=1 The management of chemical structures in a small laboratory is an important and often tedious daily task. Proprietary software is costly and by definition closed, but an open source modifiable and redistributable application, MyMolDB, described in the Journal of Computational Chemistry could make life easier for small lab managers. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25791&type=Feature&page=1 A complex approach was used to evaluate the performance of a sensory panel with two novel techniques: GCAP (Gravity Center Area/Perimeter) and CRRN (Compare Ranks with Random Numbers). Profile analysis was performed on Sri Lanka black tea batches from different plantations; for the prediction of sensory data from electronic nose results partial least square regression and support vector machine regression were used. Prediction by support vector machine gave close correlation between the results of electronic nose measurement and odor attributes. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25692&type=Feature&page=1 Antioxidants are popular as so-called anti-aging ingredients in skin creams. Now, an analysis of HPLC, MS, NMR and assay data reveals how these healthful substances might be present in the leaf buds of poplar trees. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25569&type=Feature&page=1 Quantification of MRS signals is required for providing metabolite concentrations of the tissue under investigation. However, inhomogeneities of the static magnetic field and tissue heterogeneities affect the lineshape of MRS signals and thus quantification. We propose an extension of the self-deconvolution method, by estimating and smoothing a common lineshape using a robust method with local regression. http://www.spectroscopyNOW.com/coi/cda/detail.cda?chId=9&id=25472&type=Feature&page=1 How much socioeconomic factors affect exposure to persistent organic pollutants, especially during vulnerable periods of life such as pregnancy and childhood, is not well understood. A new study investigates the relationship between maternal social class and placental concentrations of organochlorine pesticides (OCPs) and combined estrogenic activity of analytes as revealed by a biomarker for exposure.