Authors:A. Kutle, V. Oreščani, J. Obhođaš, and V. Valković
Samples of soil, plant material and water collected on the Croatian island Krk in northern Adriatic sea were analyzed for
a number of elements (Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Zr, Pb) by using energy dispersive X-ray fluorescence (EDXRF)
as an analytical tool. Some of these data have been previously used to produce geochemical map of the island.1 In addition, trace element contents of hair from children, attending elementary and secondary schools, has been investigated
using the same analytical method for Mg, S, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Hg and Pb elements. Concentrations of the twelve
elements and nine variables from the questionnaire, i.e., age, sex, living place, transportation, medication, hair colour,
hair type, type of shampoo used and hair treatment, were considered in the statistical analysis. The observed differences
for the seven island's communes have also been discussed.
Scalp hair samples from 100 individual residents in Isfahan, Iran were analyzed for Al, Br, Ca, Cu, Hg, I, K, Mg, Mn, Na, S, V, and Zn by instrumental neutron activation analysis. The results of this investigation show that the ranges of the concentration of trace elements in hair are somewhat wide, for example Mg has the range of 20 to 209 ppm for 100 subjects. The results are compared with the data reported in the literatures. A substantive correspondence between the present data and literature values from different countries, have been observed but they did not show any regular dependence. The level of iodine is significantly different from other countries and is strongly linked to local environmental factors. The correlation coefficient for Al–V, Mn–Al, Ca–Mg, and V–Mg pairs was 0.823, 0.821, 0.830 and 0.746, respectively.
Plant metabolite varies with season and geographic conditions. The present study is aimed at the identification of the potential chemotypes of Coleus forskohlii, available in the natural habitat of Nilgiri hills and adjoining area, in order to provide a basic lead for the industry concerning commercial exploitability, including the location-specific commercial cultivation of the plant. The effect of intra-specific variability in the forskolin content among the populations was estimated using high-performance thin-layer chromatography (HPTLC)—densitometric method. The roots of fourteen naturally occurring populations from the entire hill range were collected, covering the wide topography from foot hills up to the highest peak. The method developed for the quantification of forskolin was validated and found to be linear, specific, and accurate with precision and accuracy. The limit of detection (LOD) and limit of quantification (LOQ) were 1.04 and 3.16 ng spot−1. Precision studies (both inter-day and intra-day) were within the standard limit of relative standard deviation (RSD) (%) less than 3%. The quantification of forskolin within the population revealed that it varied from 0.0046 ± 0.0005 (NBC-36) to 1.156 ± 0.003% (NBC-46). The analysis of variance (ANOVA) suggested that there are significant differences in forskolin content among the populations. A positive correlation (Karl Pearson) was found between the altitude and the forskolin content. The cluster analysis of the population on forskolin content suspected the presence of two chemotypes. The study suggests the presence of chemotaxonomic variation among the populations which can be due to the change in phytogeographical factors.
Authors:Raman Preet, Raghbir Chand Gupta, and Saroj Kumar Pradhan
Among the complex mixture of biologically active compounds in Leptadenia pyrotechnica, three compounds have been used as analytical markers. A sensitive high-performance thin-layer chromatographic (HPTLC) method has been developed for the estimation. Methanolic extracts of whole plants from three populations were used on aluminum pre-coated silica gel 60 F254 plates with different mobile phases to determine the amount of β-sitosterol, lupeol, and oleanolic acid with RF value of 0.64, 0.84, and 0.47, respectively. The calibration curve was linear in the range of 2–10 μg. The method is reliable for the quantification, separation, and good resolution of these compounds from other constituents of L. pyrotechnica. To ascertain the purity of the peak from the test sample, its in-situ reflectance spectrum was compared with that from standards; the clear superimposability indicated the purity of the peaks.
Authors:Astitva Anand, Mohinder Singh Dahiya, and Rakhi Agarwal
Benzene is an omnipresent liquid in industries. The occupational exposure to benzene leads to the urinary excretion of benzene metabolites, viz., phenol, pyrocatechol, hydroquinone, and trihydroxybenzene, due to its biotransformation. These metabolites are phenolic in nature and considered as immediate biomarkers of benzene exposure. The present work includes the separation and determination of urinary phenolic benzene metabolites by coupling two different techniques. Thin-layer chromatography (TLC) was used as the separation technique to get individually separated spots of all four metabolites, which were further quantified by ultraviolet (UV)–visible spectroscopy at 765 nm. For the development of the separated spots on TLC plate and determination of metabolites by UV–visible spectroscopic method, alkaline Folin‒Ciocalteau reagent was used. Folin‒Ciocalteau reagent is having wide applications for phenol determination and gives blue color with almost all types of phenols. The colored solutions were measured against the blank disk taken from the developed spots on plastic TLC plate. Based on the obtained results, a simple, rapid, and sensitive method for the quantitation of urinary phenolic benzene metabolites has been developed and validated according to the International Conference on Harmonization (ICH) guidelines. The validated method was efficaciously applied to cigarette smokers and petrol station workers, and it was found that the method has favorable application in the routine analysis of urine samples of benzene-exposed population.
Authors:Tamás Fekecs, István Zapf, Andrea Ferencz, and Dénes Lőrinczy
Malignant melanoma is one of the most aggressive malignancies in human and is responsible for almost 60% of lethal skin tumors. Its incidence has been increasing in white population in the past two decades. The disease was classified by Clark and coworkers
Authors:Lena Stütz, Patricia Leitner, Wolfgang Schulz, and Rudi Winzenbacher
micronuclei - Part 2: Mixed population method using the cell line V79 (ISO 21427-2:2006); German version EN ISO 21427-2:2009 , Beuth Verlag , Berlin , 2009 .
German st andard methods for the examination
Thermogravimetric analysis of silica gel has shown that the loss in weight between 30° and 910°C can be quantitatively explained
on the basis of water being lost from three distinct and different populations of sites on the silica gel surface. The results
indicate that the site energies of the three different populations are randomly distributed and, consequently, the resulting
weight loss steps from each population can be described by the integral of a simple normal distribution with temperature.
The calculated weight loss obtained by assuming three different site-groups having randomly distributed adsorption energies
is, within experimental error, coincident with the experimental data. It is also shown that the water evolved from the second
population of sites originates from strongly bound water and may also contain water generated by the condensation of (geminal)
silanol groups contained in the overlapping and neighbouring population.