The merits of chemometrics in categorizing different Egyptian olive chemovarieties based on their compositional integrity were implemented in this study. Fingerprints of 9 different olive leaves varieties cultivated in Egypt were established using reversed-phase high-performance thin-layer chromatography (RP-HPTLC) prior to and after post-chromatographic derivatization with natural product-polyethylene glycol (NP/PEG) reagent and image analysis using ImageJ® software in order to build 2 separate data matrices. The chromatographic fingerprints were separately subjected to unsupervised pattern recognition multivariate analysis to build 2 separate models using principal component analysis (PCA) and hierarchical clustering analysis (HCA) algorithms to explore the distribution pattern of different chemovarieties. The second model which involved olive samples’ fingerprints after post-chromatographic derivatization exhibited greater ability to reveal a broader spectrum of phytoconstituents with enhanced sensitivity. Densitometric RP-HPTLC quantification of oleuropein marker was compared to image analysis approach using Sorbfil TLC Videodensitometer® by newly developed and validated methods. Densitometry exhibited better performance characteristics than image analysis method and therefore was executed for determination of oleuropein concentration in the 9 Egyptian olive varieties. Oleuropein marker solely was found to be inadequate for standardization of olive leaves varieties. This study demonstrated a comprehensive approach for the rapid classification of different Egyptian olive varieties, which is crucial to warranting their chemical-consistency and, thereafter, effective consistency.
The effect of microwave heating was studied in six varieties of edible oil. Variations in physicochemical properties were
observed and compared with the data obtained by hot plate heating. Fourier-transform infrared spectra of the oils showed substantial
variations after both types of heating in the region of hydrogen’s stretching (C–H) vibration, region of double bond’s stretching
(C=O), and fingerprint region. The visible spectra of mustard and olive oil showed the reduction in carotenoid, flavonoid,
and chlorophyll pigments after heating. The oil samples were discriminated as saturated, monounsaturated, and polyunsaturated
fats using chemometric techniques on physical and spectroscopic measurements.
Authors:M. Oddone, P. Márton, G. Bigazzi, and K. Biró
Obsidian samples from the Tokaj Mountains (Hungary) and from the neighbouring Zemplin Hills (Slovakia) were analysed by instrumental
and epithermal neutron activation analysis for obtaining a “fingerprint” for discrimination of potential natural sources of
raw material that would permit tracing the origin of archaeological obsidian artefacts. These techniques fully discriminate
the Zemplin Hills sources (Carpathian I, eastern Slovakia) and the Tokaj Mountain sources (Carpathian II, north-eastern Hungary)
as well as these Central European sources from those already studied of the Mediterranean basin and adjacent regions.
INAA results obtained on 11 vegetal samples proposed as European reference standards, in nutritional, agricultural and analytical studies are reported. A comparison is also reported with the data obtained by 38 European laboratories, by using spectrochemical methods (ICP atomic absorption, X-ray fluorescence, etc.). The usefulness of Instrumental Neutron Activation Analysis (INAA) is stressed, particularly when more usual methods are not sensitive enough for microelements that are important markers of toxic and pollutant substances. To this class belong lanthanides and other rare elements (Sc, Cs, Rb), which can be used both as fingerprint of soil provenance and for evaluating the homogeneity of the sample.
Authors:J. Švedkauskaitė-LeGore, G. Rasmussen, S. Abousahl, and P. van Belle
A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed
for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set
in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship
between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin
of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve
ambiguity when impurity cluster analysis fails to deliver unambiguous origin data.
study discussed the phenomena on thermal polymerization of α-methylstyrene
(AMS). A curve scanned by temperature-programmed technique was performed by
differential scanning calorimetry (DSC). Heat of polymerization (ΔH) and onset temperature of exothermic (T0) behavior were determined
to be 28010 J g-1 and about 1381C,
respectively. A dimer formation mechanism was proposed for initiation of the
propagating chain. Spectroscopic identification of dimer structure was conducted
by infrared (IR) spectroscopy in the wavenumber from 650 to 1100 cm-1associated
with molecular fingerprint characteristics. The mechanism of thermal polymerization
on α-methylstyrene proposed in this study was similar to that of styrene
suggested by Mayo.
Authors:L. S. Santos, R. R. Catharino, C. L. Aguiar, S. M. Tsai, and M. N. Eberlin
The crude methanolic extracts of a single bean from samples of organic, natural or genetically modified (GM) soybeans [Glycine max. (Merrill) L.] were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS). These extracts, containing
the most polar natural products of soybeans (free aglycones, monoglucosides, diglucosides and esters including isoflavones
and flavones) provide characteristic fingerprinting mass spectra owing to different proportions or sets of components. Spectra
distinctiveness is confirmed by chemometric multivariate analysis of the ESI-MS data, which place the three-types of beans
into well-defined groups. When ESI-MS is applied, these polar components constitute therefore unique chemotaxonomic markers
able to provide fast soybean typification.
Differential thermal analysis (DTA) was the first thermal analysis technique used to qualitatively characterize natural clays
and respective curves has been used since more than 60 years as their ‘fingerprint’. With the development of microprocessed
equipments in the last decades, derivative thermogravimetric (DTG) curves also may be used for this purpose in some cases,
which also may allow a quantitative characterization of clay components. TG and DTG curves are more indicated than DTA or
DSC curves to identify and to better analyze the several decomposition steps of natural or synthetic organoclays. These questions
are discussed in applications developed to characterize Brazilian kaolinitic clays, bentonites and organophilic clays.
Authors:Xi-yuan Zheng, Lei Zhang, Xue-mei Cheng, Zi-jia Zhang, Chang-hong Wang, and Zheng-tao Wang
In traditional Chinese medicine, plants of the genus Peganum have been used to treat cough, hypertension, diabetes, asthma, jaundice, lumbago, and many other ailments. In this study, seeds of the plants of genus Peganum, including P. harmala Linn., P. multisectum (Maxim) Bobr, P. nigellastrum Bunge, and Peganum variety were collected from different provinces in China. A simple, rapid, and effective thin-layer chromatographic (TLC) fingerprint combined with bioautographic technique has been established for the identification of acetylcholinesterase (AChE) inhibitors from these seeds. The methanol extracts of seeds were separated on silica gel plates with ethyl acetate-methanol-ammonia 10:1.5:0.5 (ν/ν) as mobile phase, and then the plates were inspected under UV 366 nm and visualized by spraying with both Dragendorff’s and vanillin-sulfuric acid reagents as well as by bioautographic assay. Moreover, the limits on AChE inhibitive activity of harmine and harmaline were found to be 0.01 μg, in comparison to that of galanthamine of also 0.01 μg. The TLC fingerprints combined with the bioautographic method could distinguish the seeds of the different species of genus Peganum investigated. Moreover, harmine and harmaline displayed similar AChE inhibition compared to galanthamine.
Authors:Rachel Popelka-Filcoff, Claire Lenehan, Michael Glascock, John Bennett, Attila Stopic, Jamie Quinton, Allan Pring, and Keryn Walshe
Ochre is a significant material in Aboriginal Australian cultural expression from ceremonial uses to its application on many
types of artifacts. However, ochre is a complex material, with associated surrounding minerals potentially challenging the
overall analysis. In recent literature several studies have attempted to characterize ochre by a variety of techniques to
understand procurement and trade. However, ochre is difficult to differentiate on major elemental or mineralogical composition
and requires a detailed analysis of its geochemical “fingerprint”. Neutron activation analysis (NAA) provides the high sensitivity
(sub-ppm), precision and accuracy in multi-elemental analysis required for ochre. The elements of interest for ochre generally
include rare earth elements (REEs) and certain transition metal elements as well as arsenic and antimony. Data from relative
comparator NAA (MURR, University of Missouri, USA) is compared with data from k0-NAA OPAL (ANSTO, Lucas Heights, Australia). A discussion of the two methods will be examined for their utility in “fingerprinting”
the provenance of ochre. The continuing importance of NAA to archaeometry will also be discussed.