Vladimir Aleksandrovich Omelchenko

2-Amino-4,6-dinitrophenol (2-A-4,6-DNP), or picramic acid, is widely used as an intermediate in organic synthesis, a dye in hair coloring products, an agricultural fungicide, and an explosive. Similar to other related compounds (2,4,6-trinitrophenol (2,4,6-TNF) and N-methyl-N,2,4,6-tetranitroaniline), of which it is a metabolite, 2-A-4,6-DNP is toxic to humans and animals. However, certain aspects of its detection in toxicological screening remain poorly understood. In this study, a mixture of acetone and acetonitrile in equal amounts was identified as the most effective extractant for 2-A-4,6-DNP. The application of gas chromatography–mass spectrometry (GC–MS) for detecting 2-A-4,6-DNP in the biological material extracts was analyzed and justified. The proposed method, based on the indirect determination of 2-A-4,6-DNP through O-acetyl derivative quantification, was employed to assess its stability in the biolo- gical material. 2-A-4,6-DNP was found to be detectable in the biological medium within 25 (storage temperature 18–22 °C) to 45 (storage temperature 1–3 °C) days after the contamination.

The aim of the work is to study the nature of the distribution of 2-A-4.6-DNP in the organisms of warm-blooded animals with intragastric administration of a toxicant. The study was carried out using the methods of TLC, UV-Visible spectroscopy, and GC-MS using derivatives of 2-A-4.6-DNP. Male Wistar rats at the age of 4 months were considered as a model of the body of a warm-blooded animal. An oily suspension of 2-A-4.6-DNF was administered intragastrically in an amount of three times the LD₅₀. Extraction of the target substance from the biomaterial was carried out by double infusion (30 minutes each) with a mixture of acetone-acetonitrile (1:1), the amount of the mixture exceeded the weight of the biomaterial by 2 times. Extractions were purified by TLC method using «Sorbfil» plates and acetone-chloroform (7: 3) mobile phase. Preliminary identification was carried out at the same time using a standard substance. Confirmatory identification was carried out by the absorption of dimethylformamide eluates in «SF-2000», as well as by the retention time and mass spectra of the major compound of the corresponding chromatographic peaks after GC-MS analysis. The quantitative content was determined spectrophotometrically, in DMF, by optical density at the analytical wavelength (490 nm). 2-Amino-4.6-dinitrophenol was found unchanged in the blood and in all the studied hollow and parenchymal organs of poisoned rats. The largest amount of 2-amino-4.6-dinitrophenol (mg/100 g) was found in the stomach walls (199.39±25.43) and stomach contents (143.14±22.63), a significant amount of the substance was found in the heart (33.49±3.66), skeletal muscles (30.70±2.64), as well as in the spleen (24.30±1.96).

ЦЕЛЬ РАБОТЫ Изучение распределения 2,4,6-тринитрофенола (2,4,6-ТНФ) у теплокровных животных с использованием физико-химических методов анализа после внутрижелудочного введения токсиканта. В процессе исследования применялись методы тонкослойной хроматографии, спектрофотометрии и высокоэффективной жидкостной хроматографии. Как модель теплокровных организмов рассмотрены четырехмесячные крысы линии Wistar (мужские особи). Исследуемое вещество в количестве трехкратной LD₅₀ вводили внутрижелудочно в водно-суспензионном состоянии. 2,4,6-ТНФ изолировали из биоматриц подопытных животных смесью ацетон—ацетонитрил (1:1) в режиме двукратного (по 0,5 ч) настаивания, выдерживая массовое отношение изолирующего агента и биоматрицы 2:1. Очистка и предварительная идентификация аналита проводилась на пластинах Сорбфил (подвижная фаза — ацетон—хлороформ (7:3)), подтверждающая идентификация — по поглощению в среде диметилформамида и по времени удерживания в колонке (64×2 мм) сорбента Сепарон С-18 при элюировании смесью ацетонитрил—вода (2:8). Оценка количественного содержания 2,4,6-тринитрофенола проводилась по оптической плотности диметилформамидного раствора аналита при 379 нм. У подопытных животных аналит обнаруживался в неизменном виде в крови, паренхиматозных и полых органах, их содержимом и крови. Наибольшее содержание 2,4,6-ТНФ (мг/100 г) отмечено в содержимом желудка (149,88±22,70), ткани желудка (97,89±4,86), крови (15,91±0,90) и мышцах (10,87±1,91).

Explosives such as tetryl and picric acid, which were common in the past, now have lost their combat relevance. However, they are often used for peaceful purposes individually and in combination with other trinitroaromatic compounds (e.g., trinitrotoluene). As a result of their use, environmental pollution occurs, followed by intoxication of plants, animals, and people. Cases of explosive poisoning during their production are also described. The symptoms of poisoning include both of general disorders and specific phenomena such as skin staining, impaired physiological efficiency of NADPh-dependent enzymes, genotoxicity, and immunotoxicity. Previous scientific studies established a trend toward the development of chemical-analytical probes. Various options for the sensor surface of the device and methods for detecting compounds are considered. To determine the explosives, ion mobility spectrometry is widely used, which is very rare for the chemicaltoxicological analysis of other groups of compounds. Simultaneously, methods commonly used in the analysis of narcotic and psychotropic substances (gas chromatography/ combination of high-performance liquid chromatography and mass spectrometry methods) are also applicable to determine trinitroaromatic explosives. However, the presence of nitro groups in their structure complicates such an analysis. This problem can be resolved by injecting cold samples directly to the column. Despite the availability of various developed techniques and methods, the possibility of their application to study biological matrices remains insufficient. Therefore, further studies of the chemicaltoxicological nature should be conducted to establish the optimal conditions for extracting the substances in question, the parameters of instrumental analysis, and the possibility of storing samples and for solving other problems of forensic medical examination.