Forensic Chemistry

FORENSIC CHEMISTRY. The domain of forensic chemistry consists of all analytical investigations conducted at the request of judicial authorities, administrative organs in preliminary investigations, sanitary protection, and mainly at the assignments of institutes of forensic medical experts and other medical establishments concerning causes of death, injuries in cases of suspected poisonings. Analyses of parts of corpses, vomit, remnants of food and beverages, medicines, cosmetic agents, water, air, and earth for the presence of 'poisonous' and 'strong-acting' substances occupy the principal place in forensic chemistry. The next task of forensic chemistry is the investigation of food products, beverages, and household items for the presence of harmful to health substances in those cases when such objects are subjects of judicial investigation. Questions about the deterioration of quality of food and other products, e.g., pharmaceutical and volatile goods, being subjects of judicial proceedings, may provide objects for forensic-chemical investigations. Questions about the pollution of air, water, and earth by waste products of industrial enterprises may also be subjects of forensic-chemical investigations. Finally, the domain of forensic chemistry includes investigations of the identity of inks and writing in cases of suspected document forgery, etc. The most developed and most frequently applied for solving questions of forensic medicine is the detection of 'poisons'. The diversity of objects, peculiarities of individual cases lead to the absence of templates for forensic chemistry: every forensic-chemical investigation is in essence a scientific investigation, differing from purely scientific investigation only in the size of the conclusion, which concerns only a particular given case. Forensic chemistry, being one of the numerous practical applications of analytical chemistry, has its own peculiarities. Thus, a characteristic feature of poison detection (toxicological analysis) is often the necessity of extracting from large amounts of investigated material infinitesimally small quantities of the sought substance, which may be a poison. This leads to the necessity of applying special, sensitive methods, which is associated with the constant danger of introducing poisons (e.g., arsenic) with reagents and vessels, even with the clothing and hair of the forensic chemist himself, therefore in the work of the forensic chemist the purity of reagents and vessels plays an especially important role. The forensic chemist should not conduct investigations of delivered objects before testing his reagents by the same methods with which he will conduct the forensic-chemical investigation itself. In this case, reagents should be taken in the same quantities in which they will be maximally applied. Usually a 'blind test' is conducted: the entire cycle of investigation is carried out with the quantities of reagents maximally used in the actual forensic-chemical investigation, but without the addition of the investigated material. The setting up of the 'blind test' must be an exact reproduction of the entire course of the investigation. Such investigations are repeated to ascertain that no extraction of impurities (arsenic) from the glass vessels that had held the reagents has occurred. Forensic chemistry in its toxicological part, initially developed and dominant to the present time, was closely connected with pharmacy: the commonality of objects, and sometimes of research methods, led to the first workers in the field of forensic chemistry being pharmacists, and on the departments of pharmacy forensic chemistry was taught. A number of professors of pharmacy—Otto, Sonnenschein, Gadamer, etc.—in Germany, Trapp, Dragendorff—in Russia—laid the foundation for this branch of analytical chemistry. Further in Germany, with the development of capitalist production, with the transition to factory preparation of chemical preparations (e.g., salts of mercury, arsenic, etc.), with the transition of pharmacists from pharmacies to pharmaceutical factories and sanitary laboratories, the production of forensic-chemical investigations also gradually transferred. In the examination for the title of 'food chemist' (Nahrungsmittelchemiker), a significant place is occupied by the examination for the detection of poisons. In France, the production of toxicological and similar analyses is entrusted to pharmacists: in the teaching program of the Paris pharmaceutical school, in the present pharmaceutical faculty of the Paris University, teaching of toxicology, which according to the program is the detection of poisons, occupies a prominent position. At present in France, England, and America, practical work in the field of forensic chemistry is carried out to a considerable extent in laboratories of municipal police. In some places of the West, work on the detection of poisons is connected with institutes of forensic medicine. It is understandable that elements of forensic chemistry are included in manuals on forensic medicine; an example of the latter is the classical manual by Kobert. In Russia of old times, forensic-chemical investigations were conducted in pharmacies. Legislation imposed on the managers of state pharmacies, and in their absence on 'keepers of free pharmacies' the conduct of forensic-chemical investigations. In the examination for the degree of pharmacist and especially master of pharmacy, 'detection of poisons' was listed, though it was largely reduced in universities to ordinary qualitative analysis. Subsequently this work passed to the laboratories of higher educational institutions. Forensic chemistry in Russia did not have official recognition: there were no special laboratories, positions, or correspondingly trained specialists. After the October Revolution, with the creation of the People's Commissariat of Health, a department of forensic medicine was founded (later replaced by the position of chief forensic medical expert, then 'inspector'). Immediately the first forensic medical laboratory with a forensic-chemical department was created. In 1932 the State Scientific Research Institute of Forensic Medicine was organized. Then regional forensic-chemical laboratories were organized. At present, forensic chemists are trained on pharmaceutical faculties of medical institutes. In the newly created People's Commissariat of Health Scientific Research Institute of Forensic Medicine, a forensic-chemical department is organized for the scientific development of questions of forensic chemistry, for the production of control tests and corresponding consultations.