Special Issues-08-01-2016

Special Issues

Vibrational Spectroscopic Discrimination of Herbal Medicines: Polygala senega, Polygala tenuifolia, and Glinus oppositifolius

August 01, 2016

Articles

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The noninvasive discrimination of powdered root material belonging to the Polygala genus and an adulterant is presented. The quality of the approach is assessed for attenuated total reflectance mid-infrared spectroscopy and diffuse reflectance near-infrared spectroscopy. Due to the pharmaceutical importance of Polygala related plant material, conclusions are drawn towards a laboratory independent discrimination of the samples.

Purity Analysis of Adulterated Essential Oils by FT-IR Spectroscopy and Partial-Least-Squares Regression

August 01, 2016

Articles

31

8

This study reported a combined use of ordinary Fourier transform-infrared spectroscopy (FT-IR) in conjunction with partial-least-square (PLS) multivariate regression for accurate determination of the percent compositions of four essential oils (EOs) (wintergreen, tea tree, rosemary, and lemon eucalyptus oils) that were adulterated either with lemongrass essential oil (LO) or peppermint essential oil (PO). The FT-IR spectra of the calibration sample sets of known compositions of adulterated EOs with LO or PO were measured and subjected to PLS multivariate regression analysis. The simplicity, low-cost, and high accuracy of the protocol makes it appealing for routine industrial quality assurance of consumable goods.

FT-IR Microscopic Analysis of Polymer Laminate Samples Including Transmission and ATR Spectroscopy

August 01, 2016

Articles

31

8

Polymer laminates typically make complex samples for infrared analysis, comprising multiple layers with defined thicknesses, in some cases less than 10 µm. When measuring extremely narrow laminate layers, the use of attenuated total reflectance (ATR) may provide improved spectra of the laminate cross-section, because ATR microscope objectives offer a greater spatial resolution than transmission due to additional magnification. This paper details the preparation of polymer laminate sample cross-sections and the collection of transmission and ATR spectra of various layers. Further analysis of the laminate spectra will also be explored utilizing a multivariate curve resolution (MCR) algorithm. An example laminate sample is examined utilizing all the tools available on a standard FT-IR microscope.

Gas Analysis with the Nicolet iS50 FT-IR Spectrometer

August 01, 2016

Application Notes (Advertising Content)

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Combining a high precision FT-IR spectrometer with a long pathlength gas cell provides a powerful tool for analyzing trace levels of contaminants in air and other gas mixtures.

Vol 31 No s8 Spectroscopy August 2016 FT-IR Technology Supplement PDF

August 01, 2016

Issue PDF

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Click the title above to open the Spectroscopy August 2016 FT-IR Technology Supplement, Vol 31 No s8, in an interactive PDF format.