RESUMO
We investigated the material properties of Cremonese soundboards using a wide range of spectroscopic, microscopic, and chemical techniques. We found similar types of spruce in Cremonese soundboards as in modern instruments, but Cremonese spruces exhibit unnatural elemental compositions and oxidation patterns that suggest artificial manipulation. Combining analytical data and historical information, we may deduce the minerals being added and their potential functions-borax and metal sulfates for fungal suppression, table salt for moisture control, alum for molecular crosslinking, and potash or quicklime for alkaline treatment. The overall purpose may have been wood preservation or acoustic tuning. Hemicellulose fragmentation and altered cellulose nanostructures are observed in heavily treated Stradivari specimens, which show diminished second-harmonic generation signals. Guarneri's practice of crosslinking wood fibers via aluminum coordination may also affect mechanical and acoustic properties. Our data suggest that old masters undertook materials engineering experiments to produce soundboards with unique properties.
RESUMO
Identifying new psychoactive substances (NPSs) and their metabolites is essential for regulating such substances for purposes of law enforcement and forensics. NPSs can be regulated on the basis of their chemical structures before they become a critical threat to society. Further, NPS metabolites can be targeted for analysis in urine, blood, and hair. This case study reports an incident in which 10 bags with approximately 15 g of crystalline material were seized from suspects by law enforcement officers and sent to the laboratory for confirmation. Gas chromatography-mass spectrometry, liquid chromatography-high-resolution mass spectrometry, and nuclear magnetic resonance (NMR) were employed to analyze these materials. The analyses revealed that the materials were a new ketamine analog, 2-fluorodeschloro-N-ethyl-ketamine (2-FDCNEK). Single-crystal X-ray diffraction (SXRD) analysis was also employed to confirm this result. In addition, metabolites of 2-FDCNEK were investigated using a fungal model and a urine sample from an abuser. The results suggest that 2-FDCNEK and 2-fluorodeschoro-norketamine are optimal metabolites for biological samples. This report presents the mass fragmentation, NMR analysis, and SXRD data of 2-FDCNEK. In addition, it provides suggestions regarding metabolites of 2-FDCNEK for law enforcement and forensic purposes, thereby facilitating the detection of this new ketamine analog.
Assuntos
Ketamina , Ketamina/análise , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas , Cabelo/química , Detecção do Abuso de Substâncias/métodosRESUMO
The identification of new psychoactive substances (NPSs) and their precursors is crucial to understand trends in NPSs so that they can be regulated before they pose a serious threat to human health. In this case, 24 bags containing approximately 600 kg of yellow powder were seized; the smugglers had been monitored for 3 years by the officers of Taiwan's Ministry of Justice Investigation Bureau. A handheld Raman analyzer yielded a positive result for N-boc norketamine; thus, the seized powder was sent to this laboratory for confirmation through gas chromatography-mass spectrometry, liquid chromatographyhigh-resolution mass spectrometry, proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), two-dimensional correlation NMR measurements (2D_COSY), heteronuclear single-quantum correlation NMR measurements (2D_HSQC), and single-crystal X-ray diffraction. This thermolabile powder was subsequently identified as 2-(2-chlorophenyl)- 2-nitrocyclohexanone (2-CPNCH), which can be employed as a precursor for the synthesis of norketamine and is available commercially. Norketamine has similar pharmacological effects to ketamine and phencyclidine but is not regulated in many countries. In this case report, mass fragments, 1H NMR, 13C NMR, 2D_COSY, and 2D_HSQC data of 2-CPNCH are presented; moreover, how criminals exploit the loopholes in the law for conducting unauthorized drug manufacturing is discussed.