[Mathematical planning of the liquid-liquid extraction procedure: a forensic chemical study of verapamil in blood]. / Matematicheskoe planirovanie protsedury zhidkost'-zhidkostnoi ekstraktsii na primere sudebno-khimicheskogo issledovaniya verapamila v krovi.

The objective of the study is to determine the optimal conditions for blood sample preparation by liquid-liquid extraction using mathematical planning of the experiment by the example of forensic chemical study of verapamil. Evaluation of verapamil recovery from blood samples was performed according to the scheme of multivariate three-level experimental planning using the Box-Behnken design. The effect of aqueous phase pH, the ratio of chloroform to n-butanol in the extraction agent, extraction and centrifugation time, addition of sodium chloride, and the ratio of sample and extraction agent volumes on the recovery was studied. The algorithm using mathematical planning and development of liquid-liquid extraction model of target analyte can be recommended for analysis procedure optimization in forensic chemistry.

[On the question of increasing the qualification of staff for the purposes of forensic-chemical and chemical-toxicological analysis: results of the questionnaire of expert chemists]. / K voprosu povysheniya kvalifikatsii kadrov dlya tselei sudebno-khimicheskogo i khimiko-toksikologicheskogo analiza: rezul'taty anketirovaniya khimikov-ekspertov.

Today, one of the most effective tools for high-quality training of specialists at the postgraduate level is continuous professional development (CPD). Additional professional education of specialists in the field of forensic chemical and chemical-toxicological analysis with higher non-medical education (pharmaceutical, chemical, biological) is carried out on the basis of pharmaceutical and medical higher educational institutions, autonomous non-profit organizations through the implementation of additional professional training programs. The timing, forms, content and technology of training by organizations implementing the corresponding educational program are of great importance. Analysis of the results of the questionnaire survey of expert chemists, carried out according to the original questionnaire in 2020-2021 in some regions of Russia, showed the main directions of development of the training system, forms and methods of teaching, the need to develop appropriate software.

[Molecularly imprinted sorbent for biological fluids sample preparation in forensic toxicology]. / Primenenie molekulyarno imprintirovannogo sorbenta dlya probopodgotovki biologicheskikh zhidkostei v sudebno-khimicheskom analize.

The objective of this work is to evaluate the possibility of biological fluids sample preparation in forensic toxicology using a molecularly imprinted sorbent based on acrylic acid derivatives. Phenylpiracetam has similar physicochemical properties to those of pyrrolidinophenone derivatives and reproduces their behavior during solid-phase extraction. The phenylpiracetam recovery from blood and urine model samples is 75% for concentration range of 100.0-6000.0 ng/ml. The accuracy of phenylpiracetam extraction does not exceed ±12% for blood samples and ±6% for urine samples. The repeatability is no more than 16% and 13% for blood and urine samples, respectively. A study of the cross-reactivity of the molecularly imprinted sorbent with some drugs showed the selectivity of the sample preparation procedure.

[Forecast of the metrological characteristics of the method of the quantitative determination of verapamil in blood in forensic chemical analysis]. / Prognoz metrologicheskikh kharakteristik metodiki kolichestvennogo opredeleniya verapamila v krovi v sudebno-khimicheskom analize.

The aim of the work is to test theoretical prognosis of metrological characteristics of methods of quantitative determination in forensic chemical analysis on the example of method of determination of verapamil content in blood by thin layer chromatography with computer densitometry. The algorithm of prognostic determination of relative error for methods of quantitative analysis in forensic chemical examination using computer program «ChemMetrEvaluation 1.0¼ is offered. The implementation of the algorithm is based on a detailed analysis of error estimation of measurements at the stages of sample preparation, measuring the value of the analytical signal.

[The use of biochemical characteristics of cadaveric blood in the forensic diagnosis of lethal poisoning]. / Ispol'zovanie nekotorykh sudebno-biokhimicheskikh pokazatelei trupnoi krovi pri diagnostike letal'nykh otravlenii.

The purpose of the work is the development of mathematical models in the forensic diagnosis of poisonings by the main groups of toxicologically important substances, on the basis of biochemical characteristics of blood. The most informative forensic and biochemical indicators of cadaveric blood used to detect lethal poisoning are the urea content, total protein content, and the ratio of urea to creatinine. Mathematical models of poisoning can be used to diagnose poisoning with narcotic drugs, psychotropic substances and substitutes of ethyl alcohol.

[The choice of the conditions for the preparation of the pregabalin samples from the biological fluids with the use of the liquid-liquid and solid phase extraction techniques]. / Vybor uslovii probopodgotovki pregabalina iz biologicheskikh zhidkostei metodami zhidkost'-zhidkostnoi i tverdofaznoi ékstraktsii.

The objective of the present study was the development of the methods for the isolation and identification of pregabalin for the purpose of chemical toxicological analysis (CTA). The authors describe the methods used to obtain pregabalin from the model mixtures of urine and blood plasma with the use of liquid-liquid and solid phase extraction. In addition, a method for the quantitative determination of pregabalin by means of combined gas chromatography mass-spectrometry was applied.

[The development and validation of the methods for the quantitative determination of sibutramine derivatives in dietary supplements]. / Razrabotka i validatsiya metodiki kolichestvennogo opredeleniya proizvodnykh sibutramina v biologicheski aktivnykh dobavkakh.

The objective of the present study was the development and validation of sibutramine demethylated derivatives, desmethyl sibutramine and didesmethyl sibutramine. Gas-liquid chromatography with the flame ionization detector was used for the quantitative determination of the above substances in dietary supplements. The conditions for the chromatographic determination of the analytes in the presence of the reference standard, methyl stearate, were proposed allowing to achieve the efficient separation. The method has the necessary sensitivity, specificity, linearity, accuracy, and precision (on the intra-day and inter-day basis) which suggests its good validation characteristics. The proposed method can be employed in the analytical laboratories for the quantitative determination of sibutramine derivatives in biologically active dietary supplements.

[The comprehensive investigation of the new psychoactive substances].

This article was designed to discuss the issues related to ensuring the methodological uniformity of investigations of the novel psychoactive substances based on the system of the newly established specialized laboratories. The authors propose the methodological approaches to the implementation of comprehensive chemical and pharmacological research including chemical, biological, and sociological studies. The main specific features of these approaches are the use of laboratory animals and the automation of in vivo experiments. Also, we discuss the use of the concrete results of the computational experiments designed to elucidate the parameters responsible for the chemical similarity of psychoactive substances. The mechanisms of their action are considered. The special emphasis is placed on the necessity of close cooperation between scientific and expert communities with a view to accumulation of the data on the newly developed and potentially harmful psychoactive substances as a basis for the efficacious prevention of their illegal trafficking.

[Detection of certain local anesthetics in biological fluids by chemo-toxicological analysis].

Analytical procedures for the detection of certain local anesthetics (including lidocaine, trimecaine, articaine, and anilocaine) in blood and urine are described with special reference to their application in chemotoxicological studies. The description is focused on the methods for isolation of the assay preparations from biological fluids and their identification with the help of up-to-date chromatographic techniques, such as thin layer chromatography, high performance liquid chromatography, and gas-liquid chromatography.

[Detection of azaleptine in forensic chemical examination of cadaveric material].

Azaleptine detection and quantitation in cadaveric material in forensic-chemical tests using thin-layer chromatography, UV-spectrophotometry, gas chromatography-mass spectrometry are outlined.

[Detection of blood opiates by fluorescence-polarization immunoassay].

It was found possible to use fluorescence-polarization immunoassay (FPIA) in screening of opium drugs in blood and blood serum as a preliminary test. The results of the study of blood and serum samples by FPIA and chromato-mass-spectroscopy were compared. As a criterion of assessment of the preliminary study results we propose to use a cutoff point by serial production of the analysed blood samples of the threshold morphine concentrations (20 ng/ml for living subjects and 40 ng/ml--for corpses). The method of opiates screening in blood proposed is characterized by fast conduction, high specificity and precision, small amounts of the expert material.

[Analysis of the structure of forensic chemical studies carried out in the Perm regional bureau of forensic medical expert evaluations in 1997-2000]. / Analiz struktury sudebno-khimicheskikh issledovanii, provedennykh v Permskom oblastnom biuro sudebno-meditsinskoi ékspertizy v 1997-2000gg.

Analysis of statistical data on forensic chemical studies carried out in the Perm Regional Bureau of Forensic Medical Expert Evaluations in 1997-2000 indicates an increased number of expert evaluations with positive results. The specific share of expert evaluations with positive results for Perm was 66.6% of the total number of evaluations. The absolute number of the detected agents in combinations with other agents increased more than 2-fold over the studied period. The number of detected agents increased 1.8 times, the rate of detection of narcotics increased sharply (6.5 times).