Identification Of Other Substances Research Articles

Identification of AD-18, 5F-MDA-19, and pentyl MDA-19 in seized materials after the class-wide ban of synthetic cannabinoids in China.

To curb the manufacturing, trafficking, and abuse of synthetic cannabinoids, China implemented a class-wide regulation on synthetic cannabinoids in July 2021. Recently, three different types of synthetic cannabinoid analogs that were not covered by the generic definitions were detected in seized powdered and e-liquid materials. These derivatives included 2-(2-(1-(4-fluorobenzyl)-1H-indol-3-yl)acetamido)-3,3-dimethylbutanamide (AD-18), N'-(1-(5-fluoropentyl)-2-oxoindolin-3-ylidene)benzohydrazide (5F-MDA-19), and N'-(2-oxo-1-pentylindolin-3-ylidene)benzohydrazide (pentyl MDA-19). Identification was based on ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance spectroscopy (NMR), and Fourier transform infrared spectroscopy (FT-IR). AD-18 is a methylene analog of ADB-FUBICA. No chemical or pharmacological data about AD-18 and 5F-MDA-19 have appeared until now, making this the first report on these two compounds. Pentyl MDA-19 has previously been reported to have high affinity for cannabinoid CB1 and CB2 receptors, but this is the first report of its presence in the recreational drug market. Moreover, the collision-induced dissociation (CID) and electron ionization (EI) characteristic fragmentation routes of AD-18 and the other two MDA-19 derivatives were also discussed to facilitate forensic laboratories in their identification of other substances with a similar structure in their case work.

CEEMD: A New Method to Identify Mine Water Inrush Based on the Signal Processing and Laser-Induced Fluorescence

The rapid and accurate identification of water source types in mine water inrush has been achieved by combining laser-induced fluorescence technology (LIF) with artificial intelligence algorithms. However, these algorithms solely rely on data and image processing analysis to identify different kinds of water samples. To address this issue, we analyzed the fluorescence spectrum and the types of mine water inrush sources from the signal point of view. Firstly, a LIF water inrush spectral analysis system was built to collect spectral data and exhibit fluorescence spectra. Different methods of spectral signal decomposition and reconstruction were compared. The complementary ensemble empirical mode decomposition (CEEMD) algorithm with a better signal evaluation index was selected to preprocess raw spectral signals. Then, the multi-class support vector machine of the cuckoo search optimization (CS-MSVM) model was implemented to the reconstructed spectral signals in different stages. The classification accuracy of the reconstructed signals in the fifth stage was 100%. Compared with raw spectra, other signal processing methods, and other different classifiers, the proposed method has the highest classification accuracy. Finally, the reliability of the algorithm was validated by using the LIF spectral signals of different edible oils and the classification accuracy was 100%. The experimental results show that the CEEMD signal processing method combined with LIF spectroscopy is effective for the accurate identification of mine water inrush source, and it also provides a theoretical basis for the spectral analysis technology that can be used for the identification of other substances.

Determination of caffeine and identification of undeclared substances in dietary supplements and caffeine dietary exposure assessment

Caffeine is one of the most consumed stimulants in the world, and is a frequent ingredient of dietary supplements. The aims of this work were to validate a GC-MS method for the quantitation of caffeine and identification of other substances in supplements, mainly weight loss products, and to estimate the caffeine intake by consumers. Sample preparation included extraction with chloroform:water in ultrasonic bath, centrifugation and analysis of the organic layer for caffeine quantitation, and extraction with methanol for identification of other substances. A total of 213 samples of 52 supplement products not registered in Brazil and seized by the Brazilian Federal Police were analyzed. From the 109 samples that declared the amount of caffeine present, 26.6% contained more than 120% of the specified content. Considering the maximum recommended dose stated on the product labels, the consumption of 47.9% of the samples would lead to a daily intake of caffeine above the safe limit of 400 mg. Undeclared drugs, including sibutramine, phenolphthalein, amphepramone and femproporex were found in 28 samples. These results show that consumers of dietary supplements should be aware that these products might contain caffeine at levels that could represent potential health risks, in addition to undeclared pharmaceutical drugs.

The Application of Flow Cytometry as a Rapid and Sensitive Screening Method to Detect Contamination of Vitreous Humor Samples and Avoid Miscalculation of the Postmortem Interval.

Research into maximizing the speed, precision, and reliability of estimating the postmortem interval (PMI) has been a recurring object of investigation and methodologies based on the vitreous humor (VH) have provided good results. However, contamination from causes not readily apparent, such as blood, can occur, and thus lead not only to an erroneous estimation of PMI, but also interfere with the correct identification of other substances in the VH. We have developed a flow cytometry method which quantifies blood contamination and is able to detect erythrocytes in 1:750,000 dilution of contaminated VH which affects the results of hypoxanthine. It is an improvement on the previous more complex mass spectrometry method, being faster, more sensitive, and readily available. As such, it could be proposed for the rapid screening of appropriate samples by detecting and eliminating blood contaminated samples from PMI estimation.

Survey on European studies of the chemical characterisation of tattoo ink products and the measurement of potentially harmful ingredients.

The results of the detection of carcinogenic aromatic amines in about 300 ink samples are discussed. All analysed inks contained at least one or more azo compound pigments, and the presence of aromatic amines could only have originated from these compounds through a chemical process named 'reductive cleavage'. Sometimes, aromatic amines were also present as impurities derived from the processing of the pigments. A systematic surveillance programme in Italy, promoted by the Italian Ministry of Health with the involvement of Italian regions, local public health authorities and Agenzia Regionale per la Protezione Ambiente del Piemonte (Environmental Protection Agency), has shown that about 40% of the monitored inks are not regular according to European Resolution ResAP(2008):1. The method utilised for the detection of aromatic amines has allowed the identification of other substances that are not carcinogenic but are toxic or have sensitisation properties that are derived from reductive cleavage or that are present as impurities.

Nutritional aspects of cereals

Nutritional aspects of cereals

Noninvasive sampling of phenylalanine by reverse iontophoresis

While iontophoresis is typically associated with drug delivery across the skin, the symmetry of the technique permits its application to the essentially noninvasive withdrawal of biologically important analytes from the subcutaneous space to the body’s surface. The identification of other substances which can be monitored by this procedure, and to its optimization and development as a more general clinical chemistry tool, is a long-term objective. In this paper, we describe a preliminary in vitro investigation into the feasibility of extracting and analyzing the amino acid, phenylalanine, with the ultimate aim to develop a diagnostic test for phenylketonuria, a potentially fatal metabolic disease in infants. Over a subdermal concentration range of 1–10 mM phenylalanine, reverse iontophoretic extraction was rapid, easily detectable and highly linear. Manipulation of the electrolyte composition surrounding the cathode (i.e., the site of collection of the iontophoretically-extracted material) enabled phenylalanine to be electrotransported at a rate of approximately 6 nmol/cm2/h when present subdermally at 1 mM. The potential exists, therefore, to use this approach for the noninvasive detection of systemic amino acid levels in vivo. However, such a development will necessitate a suitable and convenient analytical approach (e.g., a biosensor), with a sensitivity about 10-times greater than that used in this work, which can be combined successfully with the reverse iontophoretic extraction technology.