Formation of an interfering substance, 3,4-dimethyl-5-phenyl-1,3-oxazolidine, during a pseudoephedrine urinalysis

During fatal aviation accident investigations, biosamples from the victims are submitted to the FAA Civil Aeromedical Institute (CAMI) for drug analysis. In the process of one such analysis by CAMI, an unknown substance was found in a urine sample. Simultaneous screening by thin layer chromatography (TLC) and gas chromatography/FID (GC/FID) suggested the presence of pseudoephedrine. A subsequent routine confirmation analysis of a separate urine aliquot by GC Fourier transform infrared (GC/FTIR) and GC mass spectrometry (GC/MS) indicated that the retention times of the unknown substance matched with those of pseudoephedrine. However, its infrared and mass spectra were different--the -OH and -NH groups were missing, a C-O-C group was present, and the molar mass was 12 atomic mass units (amu) more than that of pseudoephedrine. A subsequent literature search suggested that ephedrine-like amines react with aldehydes to form oxazolidines. Therefore, the 12-amu increase could be accounted for by condensation of pseudoephedrine with formaldehyde. Since this aldehyde is present in various grades of methanol and ethyl acetate, and these solvents were used during the solid-phase extraction, 3,4-dimethyl-5-phenyl-1,3-oxazolidine was synthesized by using (+)-pseudoephedrine HCl and formaldehyde. The analytical findings of the synthesized compound were consistent with those of the unknown interfering substance, confirming that it was the oxazolidine. Aldehyde contaminants in solvents or specimens can transform drugs of interest and may result in misidentification of a compound originally present in specimens. Therefore, chemicals used in analyses should be of the highest available purity, and a multi-analytical approach should be adopted to maintain a high degree of quality assurance.     

Diagnostic role of acute microscopic changes in myocardium

Forensic medical diagnosis of death from coronary heart disease, acute ethanol poisoning, alcoholic cardiomyopathy, closed cardiac injuries, mechanical injuries incompatible with life which may be directly caused by acute cardiac failure, requires identification and evaluation of diagnostic complexes of acute myocardial changes. The diagnostic significance of such complexes of myocardial changes is characterized for the first time. A method for evaluation of such changes, addressed to expert histologists, is presented.     

Detection of semen in stains on material evidences by quantitative immunofluorescence test

Russian and foreign methods used in forensic medicine for detection of the semen in stains on material evidences are compared. The potentialities of quantitative immunofluorescence test for detection of the semen in stains on material evidences, developed at Bureau for Forensic Medical Expert Evaluations of the Leningrad region, are described. Unlike other methods used in Russia, this method detects the semen in stains in the absence of spermatozoa and in stains with very low amount of the semen. Our modification allows objective recording of the results with computer processing. The method is cheaper than its foreign analogs and its sensitivity is similar to them.     

Forensic medical evaluation of professional working capacity in victims, who needs additional care

The philosophy of evaluating the need of a victim in extra care is discussed. The method for evaluating the need in transport vehicles for the victim is described in detail. Legislative documents which help solve such problems are cited, including those used by committees of forensic medical evaluations.     

Study of microinjuries to hair cuticle of human head by scanning electron microscopy

The author presents the data on microclues in the free edges of hair cuticles of human head: microinjuries, microdefects (cracks, breaks, clefts, large and small waves) in representatives of Asia, Africa, Latin America, and Eastern Europe. The studies were carried out by scanning electron microscopy. Microinjuries of cuticle cells forming during hair combing by different types of combs and as a result of "permanent" curling are described. Scanning electron microscopy at the optimal magnification of x 3000 is a highly informative method for investigating microinjuries to the hair cuticle as additional signs in expert evaluation of the hair.     

Structure of hair on the head and other parts fo body in Latin Americans

The structure of hairs from the head, chest, armpits, and pubis of residents of Latin America (Bolivia, Salvador, Panama, Ecuador, Chile, Nicaragua, Venezuela, Peru, Brasil, and Mexico) has been studied. New data on macro- and microscopic characteristics of hairs of the population of the above countries were obtained (color, shape, length, thickness of hair; number of cuticle lines; characteristics of hair layers, shapes of transverse sections, etc.).     

Comparative analysis fo heroin

A protocol for comparative analysis of heroin making use of chromatographic methods and infra-red spectroscopy is presented.