Vol 72, No 6 (2017)

The problems and peculiarities of obtaining the kinetic characteristics of extraction of biologically active substances (BAS) from a plant matrix are discussed. The establishment of kinetic characteristics of the extraction of BAS under various extraction conditions is studied on the example of samples of Hypericum perforatum and Salvia officinalis. The lowest value of the average rate constant of the extraction of BAS from the materials examined is characteristic of a variant of static extraction with an aqueous alcohol extractant under heating. The methods of static extraction under heating (according to the requirements of pharmacopoeia articles) and ultrasonication, as well as using double ultrasonication differ little from each other in their kinetic efficiency. The method of dynamic extraction of BAS at an elevated temperature and pressure is characterized by the highest values of the rate constant, which leads to an acceleration of the diffusion of the BAS into the extractant’s medium. It is noted that the extraction processes and chemical transformations of some BAS (hyperforin, carnosic acid, etc.) occur simultaneously as confirmed by the decrease in their concentrations in the extractant during the extraction from plant samples.

In the present research, we compared two datasets obtained from the quantitative estimation of ERCC1 protein using two monoclonal antibodies—8F1 and FL29. Quantitative evaluation of immunofluorescence parameters was performed by flow cytometry on ovarian cancer biopsy specimens (n = 53). Agreement between two different assays was estimated by correlation analyses and Bland–Altman plots. It was shown that, despite of large spread of differences etween two measurements obtained by 8F1 and FL297, both clones may be used for estimation of ERCC1 expression level (i.e., the number of positively stained cells) in tumor.

Novel 2-mercaptobenzotellurazole derivatives with different functional groups were obtained using its mercapto group.

The possibility of using microemulsions as extractants during the extraction of chemical markers from oil samples and their subsequent preconcentration by the decomposition of microemulsions and determination of oil components by the gas chromatography-mass-spectrometry method is shown. Due to hydrophobicity, oil components pass into the organic phase after the decomposition of microemulsions and become concentrated due to the reduction of the volume of one of the phases. It is shown that as the preconcentration of the precipitant increases, the preconcentration coefficient of the chemical markers grows to 8–10. The method itself is characterized by low detection limits, good selectivity, and reproducibility.

The possibility of directly determining 36 pesticides (derivatives of urea, triazines, triazoles, imidazoles, carbamates, triazinones, benzamides, and pyridazinones and organophosphorus pesticides) by electrospray ionization with high-resolution quadrupole time-of-flight mass spectrometry in natural waters is demonstrated. A significant matrix effect is observed in the determination of pesticides in natural waters, and the use of the standard addition method is proposed for their determination in test samples, both undiluted and diluted with deionized water. The analytical range of the analytes was 0.5–50 ng/mL. The relative standard deviation of the results does not exceed 10%; the time required for the analysis is 10–15 min.

A new format for the express method of visual semiquantitative analysis based on the principle of gradient lateral flow immunoassay with gold nanoparticles as a label is proposed. Several test bands with an increasing concentration of specific antibodies immobilized on the membrane are formed in the analytic zone of the test strip. The antigen content is semiquantitatively evaluated visually by counting the number of visible colored bands in the analytic zone. By the example of the human chorionic gonadotropin hormone, the possibility of noninstrumental semiquantitative determination of the antigen in the range from 50 to 10000 mU/mL for 5–10 min was shown in five concentration ranges: under 100, 100–300, 300–500, 500–800, and above 800 mU/mL. The developed semiquantitative express method allows visually determining the concentration range of human chorionic gonadotropin in the urine by the number of colored bands for diagnosing pregnancy and its course.