Fe Content Of Samples Research Articles

Geochemical records and environmental analysis of the Ediacaran-Cambrian boundary in Eastern Yunnan, South China

The Ediacaran–Cambrian transition is characterized by an unprecedented change in biosphere, lithosphere, and atmosphere. However, the identification of this transition and its global correlation remains debated. East Yunnan is a region of utmost importance in the study of the Ediacaran-Cambrian transition. Although strata from this region have been well studied, recognition of the base of the Cambrian continues to be controversial. This paper presents, a carbon chemostratigraphic isotope and trace element profile through the Dengying and Zhujiaqing formations in the Sujiawa section in East Yunnan. Through carbon isotope and trace element analyses of the Dengying and Zhujiaqing formations we attempt to regionally correlate the section and discuss the paleo-marine redox environment changes during this period. The Fe content of samples is low and the Mn/Sr ratios of the majority of the Sujiawa section samples is lower than 10 and shows no correlations with δ13Ccarb and δ18Ocarb values, indicating that the samples retain near-primary δ13Ccarb characteristics. The carbon isotope profile from the Sujiawa section, shows a prominent negative δ13Ccarb in the basal Zhongyicun Member (N1’, −7.3‰) that most likely represents the prominent negative excursion recorded in Ediacaran-Cambrian strata across the world. REE patterns and Y/Ho ratios were used to screen samples, to ensure that the primary seawater REE features and Ce anomalies were preserved. The samples satisfying this screening process show seawater-like REE distribution patterns in leached carbonates and may have recorded Ce anomalies of the seawater from which the carbonates precipitated. These data show that the Baiyanshao Member has Ce/Ce* values between 0.57 and 0.88, the Daibu Member between 0.56 and 0.83, and the Zhongyicun Member between 0.60 and 0.96. The Ce anomalies through the section indicates that the region experienced suboxic-oxic-anoxic conditions throughout the Ediacaran-Cambrian period. Carbon isotope and trace element analyses indicate that the strata record a negative carbon isotope excursion event and anoxic conditions during the period of deposition. This study complements the carbon chemostratigraphic information and trace element data in the region and provides valuable clues for understanding the lithofacies changes through the Ediacaran and Cambrian in different regions of South China.

A Study on Vitamin C Content of Nutrition Emphasized Products

Objectives: Vitamin C has various functions such as antioxidative effect and supporting absorption of iron (Fe). Aim of this present study was to provide vitamin C nutrition information and to briefly evaluate absorption interaction of vitamin C and Fe content of vitamin C emphasized products. Methods: Vitamin C emphasized foods including beverages, cereal, snacks, chocolate products, other cocoa products, and sugary products were examined by HPLC. Fe contents in samples after dry-ashing were examined by ICP. Results: Vitamin C content ranges in various products tested were the following: beverages (n=11) 20.15 ± 0.08~845.41 ± 6.07 mg, cereal (n=11) 52.50 ± 0.23~262.50 ± 0.07 mg, snacks (n=1) 50.00 ± 0.25 mg, chocolate products (n=1) 311.73 ± 2.44 mg, other cocoa products (n=1) 311.73 ± 2.44 mg, other sugary products (n=2) 52.50 ± 0.23~262.50 ± 0.07 mg. Vitamin C (n=27) analysis values ranged from 82 to 450% of the labeled value. Vitamin C content in vitamin C emphasized food (n=6) was estimated 7.7 times~56.6 times more than Fe content. Conclusions: Analyzed samples ranged more than 80% of the labeled value in vitamin C emphasized products, which complied with food labeling regulation. But, beverages (n=3), cereal (n=4), chocolate products (n=1) were 2 times more than the labeled value. To provide accurate nutrition information, food manufactures should supervise nutrition labeling and understand the interactions between nutrients. Also, consumer should decide about the adequate amount of nutrient intake by thoroughly checking nutrition labeling.

Superconductivity in Fe1+d Te0.9Se0.1 Induced by Deintercalation of Excess Fe Using Alcoholic Beverage Treatment

Superconductivity in polycrystalline Fe1+d Te0.9Se0.1 was enhanced by heating in alcoholic beverages. We found that part of the excess Fe was deintercalated from the interlayer sites by the treatment and the shielding volume fractions were increased with the reduction of excess Fe content in sample. This behavior is similar to the case of Fe1+d Te1−x S x . Thus the technique of alcoholic beverage treatment can be applied generally to the Fe-chalcogenide superconductors.

The effect of NPK treatments on the Cu and Fe content of winter wheat (Triticum aestivum L.)

In this study the effect of N, P and K nutrients on the Cu and Fe content of winter wheat (Triticum aestivum L.) grains was investigated in a long-term fertilization experiment set up in Nagyhörcsök. Samples were also harvested from four experimental stations of the Hungarian national long-term fertilization trials. These are the following: Bicsérd, Iregszemcse, Karcag, and Putnok. Plant samples were collected in 2005 which was very wet. Our results from Nagyhörcsök were compared with the Cu and Fe content of samples which were harvested from control plots of other experimental stations. The Cu and Fe content of grain samples were measured using inductively coupled plasma mass spectrometer (ICP-MS) followed by digestion with HNO3-H2O2 solution. All data were subjected to ANOVA, and when significant differences (P<0.05) were detected, Duncan’s test was performed to allow separation of means.
 The main conclusions are as follows: Cu and Fe content of wheat grains was higher and higher in every NPK treatments. Samples were harvested from the control plots of Iregszemcse and Bicsérd have higher Cu content than the treated samples from Nagyhörcsök.

Controlling synthesis of Fe nanoparticles with polyethylene glycol

This study looks at the synthesis of Fe nanoparticles using a borohydride reduction of metal salts in the presence of carboxyl and methoxyl terminated polyethylene glycol (PEG). As the PEG concentration is varied, there is a corresponding increase in the Fe content of samples as determined by Mossbauer spectroscopy. Particle sizes are between 70 and 300 nm as indicated by transmission electron microscopy. As the polymer concentration is increased the overall saturation magnetization of the coated nanoparticles initially increases due to the increased iron content with a maximum of 70 emu/g for nanoparticles with the largest Fe content. The magnetization then begins to decrease as the polymer concentration begins to contribute to a significant volume fraction of the sample. All samples are magnetically soft with high remanence as indicated by SQUID magnetometry measurements.

“Lag” — a geochemical sampling medium for arid regions

Desert land surfaces are commonly characterized by a veneer or pavement of siliceous and/or ferruginous stony material. This material can be shown in most cases to be predominantly bedrock-derived, despite often severe modification by prolonged weathering, and can therefore be selectively sampled and analyzed as an indicator of bedrock geochemistry in geochemical surveys. Most pavements probably owe their existence to the interaction of several dispersion mechanisms. However, a common factor in all cases is the concentration of coarse particles at the surface as a result of the selective removal by erosion of fine dilutant material. Hence, the preferred name when used in the geochemical context is “lag”. In lag sampling, particles in the range 2.0–6.0 mm are screened on site from the unconsolidated surface material. Material in this size range has been found to be quite uniformly distributed over a wide range of arid region environments, including areas where residual soils are severely diluted by transported alluvial and aeolian materials. Data from exploration programmes for Au, Cu-Pb-Zn-Ba, and Ni allow comparison of results for lag sampling with those for alternative sample media in a variety of arid region environments. Analysis of lag samples for Au, Cu and As clearly indicates the presence of bedrock Au mineralization in the Paterson and Eastern Goldfields Provinces of Western Australia. In these areas both lags and soils exhibit good anomaly contrast, but lags show more extensive lateral dispersion, leading to advantages in reconnaissance exploration. Strong anomalies for Ni and Cu are developed in lags, compared with subdued response in fine-fraction soils over a Ni sulphide occurrence in the Eastern Goldfields which has been subjected to deep lateritic weathering. Lag geochemistry also clearly reflects sub-economic base metal and barite occurrences in the McArthur Basin, N.T., in spite of the dilution of surface soils by sands probably related to a Mesozoic marine incursion. Orientation sampling over a Pb-Zn prospect in the Pine Creek Geosyncline has demonstrated optimum response in lag samples compared with various size fractions of the associated lithosols. Variable dilution of lag samples by coarse quartz sand can be a problem in areas with substantial transported overburden. A simple procedure to ‘correct’ trace-element values using regression analysis based on the Fe content of samples is described as a means of reducing ‘noise’ resulting from such matrix variations.