Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Forensic Sci ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39135315

RESUMO

In the United States, illicit fentanyl is often trafficked as blue tablets mimicking the legitimate M-30 oxycodone tablet produced by Mallinckrodt. The analysis of dyes extracted from seized fentanyl tablets could provide a useful tool for law enforcement to establish linkages between cases and could prove useful for attributing a seizure to a given trafficking organization. Fentanyl tablet seizures associated with a particular drug trafficking organization (DTO), either through investigative or intelligence information, were used as the sample set for this study. The blue dye from the tablets was isolated by solid phase extraction and then qualitatively and quantitatively analyzed via ultraviolet-visible spectroscopy. This research revealed that the illicit tableting facilities use a different dye than several known pharmaceutical companies. The concentration of dye in individual tablets within a seizure proved to be very minimal, and the small sample size made it difficult to draw linkages from case to case. Analysis of the dyes could not effectively differentiate between the drug trafficking organizations in the tested population due to each DTO using the same dye; however, it is important to note that the dye found was consistent between illicit tablets.

2.
J Forensic Sci ; 66(1): 285-294, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32956496

RESUMO

The analysis of cannabis plant material submitted to seized-drug laboratories was significantly affected by the signing of the Agricultural Improvement Act of 2018, which defined hemp and removed it from the definition of marijuana in the Controlled Substances Act. As a result, field law enforcement personnel and forensic laboratories now are in need of implementing new protocols that can distinguish between marijuana-type and hemp-type cannabis. Colorimetric tests provide a cost-effective and efficient manner to presumptively identify materials prior to submission to a laboratory for analysis. This work presents the validation of the 4-aminophenol (4-AP) color test and demonstrates its utility for discriminating between marijuana-type and hemp-type cannabis (i.e., typification). Validation studies included the testing of numerous cannabinoid reference materials, household herbs, previously characterized cannabis plant samples, and real-case samples. The 4-AP test reliably produces a pink result when the level of Δ9 -tetrahydrocannabinol (THC) is approximately three times lower than the level of cannabidiol (CBD). A blue result is generated when the level of THC is approximately three times higher than that of CBD. Inconclusive results are observed when the levels of THC and CBD are within a factor of three from each other, demonstrating the limitations of the test under those scenarios.


Assuntos
Aminofenóis/química , Cannabis/química , Colorimetria , Canabinoides/análise , Dronabinol/análise , Humanos
3.
J Colloid Interface Sci ; 446: 163-9, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25666457

RESUMO

Over the past several years, nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) have been introduced into the scientific literature involving many analytical, biological, and technological applications. In this regard, these nanoGUMBOS have been shown to display a number of unique properties including fluorescence, magnetism, tumor targeting, and optoelectronic. To date, however, little focus has been placed on developing and refining approaches for generation of size-controlled nanoGUMBOS from GUMBOS building blocks. Herein, we describe a systematic effort to define various strategies for the production of well-defined nanoGUMBOS. Specifically, we describe methods based on (i) sonochemical, (ii) microwave-assisted, (iii) cyclodextrin-assisted, and (iv) surfactant-assisted syntheses of nanoGUMBOS, evaluating the efficiency of each technique in controlling the size, sphericity, and uniformity of nanoGUMBOS produced. The effect of systematic variation in experimental parameters such as concentration, cation-to-anion ratio, as well as presence and type of template introduced for formation of nanoGUMBOS is also investigated.


Assuntos
Ciclodextrinas/química , Nanopartículas/química , Compostos Orgânicos/química , Sais/química , Tensoativos/química , Fluorescência , Microscopia de Fluorescência , Micro-Ondas , Propriedades de Superfície
4.
Photochem Photobiol Sci ; 13(9): 1270-80, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24976521

RESUMO

A new kind of material called nanoGUMBOS, comprised entirely of cations and anions, has been developed by pairing various functional ions that exhibit fluorescence activity with biocompatible ions, in a process very much akin to that employed in ionic liquid chemistry. In the present study, spectral and biological properties of NIR absorbing nanoGUMBOS were evaluated using electron microscopy, dynamic light scattering, absorbance, thermal imaging, and live/dead fluorescence assays in conjunction with malignant MDA-MB-231 and non-malignant HS-578-BST epithelial human breast cells. The primary focus of this study was to maximize heat generation using NIR laser irradiation and minimize non-specific cytotoxicity using biocompatible constituent ions (e.g. amino acids, vitamins, or organic acids). Concurrently, in order to generate highly responsive nanomaterials for NIR-laser-triggered hyperthermia, optimization of the nanoparticle size, shape, and uniformity was carried out. Evaluation of data from hyperthermal studies of NIR absorbing nanoGUMBOS shows that these materials can achieve temperatures above the threshold for killing cancerous cells. Additionally, in vitro cell based assays demonstrated their promising hyperthermal effects on cancer derived epithelial cells.


Assuntos
Nanoestruturas/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Feminino , Ácido Fólico/química , Humanos , Hipertermia Induzida , Lasers , Microscopia de Fluorescência , Nanoestruturas/toxicidade
5.
Appl Spectrosc ; 68(3): 340-52, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24666951

RESUMO

The photothermal properties of several near-infrared-absorbing nanoparticles derived from group of uniform materials based on organic salts (GUMBOS) and composed of cationic dyes coupled with biocompatible anions are evaluated. These nanoparticles were synthesized using a reprecipitation method performed at various pH values: 2.0, 5.0, 7.0, 9.0, and 11.0. The cations for the nanoparticles derived from GUMBOS (nanoGUMBOS), [1048] and [1061], have absorbance maxima at wavelengths overlapping with human soft tissue absorbance minima. Near-infrared-absorbing nanoGUMBOS excited with a 1064 nm continuous laser led to heat generation, with an average temperature increase of 20.4 ± 2.7 °C. Although the [1061][Deoxycholate] nanoGUMBOS generated the highest temperature increase (23.7 ± 2.4 °C), it was the least photothermally efficient compound (13.0%) due to its relatively large energy band gap of 0.892 eV. The more photothermally efficient compound [1048][Ascorbate] (64.4%) had a smaller energy band gap of 0.861 eV and provided an average photothermal temperature increase of 21.0 ± 2.1 °C.

6.
Langmuir ; 26(19): 15599-603, 2010 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-20809597

RESUMO

Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. In the work presented here, nanoparticles prepared using an aerosolization process were derived from europium-based GUMBOS (Group of Uniform Material Based on Organic Salts). These nanoparticles were characterized using electron microscopy, X-ray photoelectron spectroscopy (XPS), absorbance, and photoluminescence spectroscopy. An average diameter of 39.5 ± 8.4 nm for our nanoparticles was estimated by use of electron microscopy. Absorbance, luminescence, and luminescence lifetime decay measurements indicate intense and steady luminescence, which suggests a multitude of possible applications for lanthanide-based GUMBOS, especially in sensory devices, OLEDs, and photovoltaic devices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA