The influence of English colonization on culture of Australians

Several lignite samples were collected from boreholes of the Amynteo opencast lignite mine, northern Greece. Organic geochemical characteristics were investigated with the help of various analytical techniques, comprising Gas Chromatography (GC) and Gas-chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared Spectroscopy (FTIR), solid-state Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR) spectroscopy, petrographical measurements as well as determination of bulk parameters. In the low rank (Rr = 0.21%) Amynteo lignites, huminite is the most abundant maceral group, inertinite has relatively low percentages and liptinite concentrations are rather high. Carbon Preference Index (CPI) reveals the predominance of odd-numbered, long-chained aliphatic hydro-carbons, which is related to a higher terrestrial plant input. The Pr/Ph ratio suggests that reducing conditions were persistent during peatification. Gymnosperm biomarkers such as isoprimarane, abietane, phyllocladane and sandaracopimarane, as well as angiosperm indicators (lupane) and hopanoid compounds with bacterial origin were identified. Analyses of the aromatic fractions revealed the presence of naphthalene, alkyl benzenes and phenols, pyrene, cadalene, cadinane, fluoranthene and dibenzofurane. Based on the FTIR analysis, aliphatic and oxygen containing structures were prevailed over the aromatic moieties. The intensity of the mineral bands was preferentially increased in the FTIR spectra of insoluble material. According to NMR analysis, the aliphatic carbons (0-50 ppm) have higher proportions comparing to aromatic carbons (100-160 ppm). The aromaticity fraction is low (fa = 0.32), as expected for these low rank coals. The presence of free organic radicals and Fe3+ and Mn2+ paramagnetic ions was revealed by EPR. In summary, the combined application of complementary analytical techniques allowed a deep inside into the geochemical characteristics of Amynteo lignites

Diagnostic utility of zinc protoporphyrin to detect iron deficiency in Kenyan pregnant women

Iron-deficient erythropoiesis results in excess formation of zinc protoporphyrin (ZPP), which can be measured instantly and at low assay cost using portable haematofluorometers. ZPP is used as a screening marker of iron deficiency in individual pregnant women and children, but also to assess population iron status in combination with haemoglobin concentration. We examined associations between ZPP and disorders that are common in Africa. In addition, we assessed the diagnostic utility of ZPP (measured in whole blood and erythrocytes), alone or in combination with haemoglobin concentration, in detecting iron deficiency (plasma ferritin concentratio

Interactions between a humic acid and a paramagnetic cation as assessed by CPMAS 13C NMR spectroscopy

Humic substances (HSs) are natural organic materials playing a very important role in environment due to their ability in interacting with organic and inorganic compounds. From the one side, HSs can reduce the toxic effects of organic and inorganic contaminants, while, from the other side, they can enhance availability of nutrients, such as cations, to living organisms including plants. For this reason it is very crucial to understand the mechanisms of the interactions between humic substances and the environmentally relevant chemical components. In the present work, we have investigated the mechanisms of interaction between a HS and iron (III) by using cross polarization magic angle spinning (CPMAS) 13C NMR spectroscopy. For that, complexes between HS and different amounts of Fe(III) were prepared. All the HS-Fe(III) complexes were analysed by variable contact time (VCT) NMR experiments in order to obtain estimations of the values of the cross-polarization time (TCH) and the proton longitudinal relaxation time in the rotating frame (T1rho(H)). Results confirmed literature findings by which carboxyl groups are the most important humic fraction endowing with the ability to chelate Fe(III). However, our results also demonstrated that direct bondages between HS and Fe(III) involve the remaining polar systems such as carbohydrates and peptides. Conversely, alkyls and aromatics appeared not to be directly bound to the paramagnetic iron (III). We also evaluated the distances between Fe(III) and the different functional groups in the HS through the analysis of the proton spin diffusion into the HS-Fe(III) complexes

Improving Quantification of 13C CP-MAS NMR by steady state and well-defined data processing in variable contact time experiments

C-13 CP-MAS NMR is used as a non-destructive technique to measure the distribution of carbon types in humic substances. Although it is well-known that quantification of CP-MAS is problematic because different parts of the spectrum have different optimal contact times, a single contact time is used in most studies and in such cases C-13 CP-MAS NMR is only qualitative. Using Variable Contact Time experiments and back-extrapolating the signals for the various chemical shift regions to t=0 significantly improves quantification. Because signals decrease markedly during the beginning of an experiment, samples need a steady-state condition before acquisition of the Free Induction Decay (FID). Well-defined processing of the raw data significantly improves data quality. The effect of these various treatments on overall accuracy is shown