DEVELOPING THE METHODS OF FOOD PRESERVATIVES EXTRACTION FROM COMPLEX MATRICES FOR BIOASSAY PURPOSE

The presence of food additives in food products may be associated with the risk of their toxic effects on human body. Therefore, the study of approaches to testing their safety seems to be a particularly urgent task. The aim of this study was to determine the conditions for extracting food preservatives from the samples of preserved pureed vegetables for further bioassay of the extract obtained in the Allium test. Onion roots were used as a test object in this method. Two extraction methods of benzoic and sorbic acids added to pureed vegetables have been developed. Distilled water and acetone were used as extracting solutions. The extraction efficiency was evaluated on Shimadzu Prominence LC-20 liquid chromatograph (Japan) in the ultraviolet range, wavelength 235 nm (benzoic acid), 285 nm (sorbic acid). According to the results of studies using both water and acetone as extractants, the degree of preservatives extraction was approximately the same and quite high. In the quantitative calculation of the preservatives content in pureed vegetables, the value of the correction factor was 0.8. However, due to certain production characteristics of this product, i. e. the stage of cauliflower homogenization, obtaining an extract with acetone seems to be more acceptable for the Allium test conditions.The presence of food additives in food products may be associated with the risk of their toxic effects on human body. Therefore, the study of approaches to testing their safety seems to be a particularly urgent task. The aim of this study was to determine the conditions for extracting food preservatives from the samples of preserved pureed vegetables for further bioassay of the extract obtained in the Allium test. Onion roots were used as a test object in this method. Two extraction methods of benzoic and sorbic acids added to pureed vegetables have been developed. Distilled water and acetone were used as extracting solutions. The extraction efficiency was evaluated on Shimadzu Prominence LC-20 liquid chromatograph (Japan) in the ultraviolet range, wavelength 235 nm (benzoic acid), 285 nm (sorbic acid). According to the results of studies using both water and acetone as extractants, the degree of preservatives extraction was approximately the same and quite high. In the quantitative calculation of the preservatives content in pureed vegetables, the value of the correction factor was 0.8. However, due to certain production characteristics of this product, i. e. the stage of cauliflower homogenization, obtaining an extract with acetone seems to be more acceptable for the Allium test conditions

Modes of magnetic resonance of S=1 dimer chain compound NTENP

The spin dynamics of a quasi one dimensional $S=1$ bond alternating spin-gap antiferromagnet Ni(C$_9$H$_{24}$N$_4$)NO$_2$(ClO$_4$) (abbreviated as NTENP) is studied by means of electron spin resonance (ESR) technique. Five modes of ESR transitions are observed and identified: transitions between singlet ground state and excited triplet states, three modes of transitions between spin sublevels of collective triplet states and antiferromagnetic resonance absorption in the field-induced antiferromagnetically ordered phase. Singlet-triplet and intra-triplet modes demonstrate a doublet structure which is due to two maxima in the density of magnon states in the low-frequency range. A joint analysis of the observed spectra and other experimental results allows to test the applicability of the fermionic and bosonic models. We conclude that the fermionic approach is more appropriate for the particular case of NTENP.Comment: 11 pages, 11 figures, published in Phys.Rev.

Novel magnetic phases in a Gd2Ti2O7 pyrochlore for a field applied along the [100] axis

We report on longitudinal and transverse magnetisation measurements performed on single crystal samples of Gd2Ti2O7 for a magnetic field applied along the [100] direction. The measurements reveal the presence of previously unreported phases in fields below 10 kOe in an addition to the higher-field-induced phases that are also seen for H//[111], [110], and [112]. The proposed H-T phase diagram for the [100] direction looks distinctly different from all the other directions studied previously.Comment: 4 pages, 5 figure