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5,171 result(s) for "Volatile solvents"
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GC-MS silylation derivative method to characterise black BIC® ballpoint 2-phenoxyethanol ratio evaporation Profile : a contribution to ink ageing estimation
One of the major challenges in forensic document analysis is estimating the age of ink deposition on a manually written document. The present work aims to develop and optimise a methodology, based on the evaporation of 2-phenoxyethanol (PE) over time, that can contribute to ink age estimation. A black BIC® Crystal Ballpoint Pen was purchased in a commercial area, and ink deposition began in September 2016 over 1095 days. For each ink sample, 20 microdiscs were subjected to n-hexane extraction in the presence of an internal standard (ethyl benzoate) followed by derivatisation with a silylation reagent. A gas chromatography-mass spectrometry (GC/MS) method was optimised for PE-trimethylsilyl (PE-TMS) to characterise the ageing curve. The developed method presented good linearity between 0.5 and 50.0 μg mL−1, as well as limits of detection and quantification of 0.026 and 0.104 μg mL−1, respectively. It was possible to characterise PE-TMS concentration over time, which reveals a two-phase decay behaviour. First, there was a substantial decline between the 1st and the 33rd day of deposition, followed a by a stabilisation of the signal, which allowed to detect the presence of PE-TMS up to 3 years. Two unknown compounds were also present and allowed to identify three dating time frames for the same ink stroke: (i) between time 0 and 33 days, (ii) between time 34 and 109 days, and (iii) more than 109 days. The developed methodology allowed to characterise the behaviour of PE over time and to establish a relative dating of three-time frames.
A simple strategy for washing a recrystallized drug from viscous and non-volatile solvents prior to XRD study: A technical note
Aim: obtaining a dried powder residual from a viscous and non-volatile solvents isimpossible. Thus, their analysis by using the methods required for the dried formof materials has always been a problem. In the current technical note, our aim wasto offer a simple method for this issue. Results: the proposed method was basedon washing of the viscous residuals with a volatile solvent and their drying in theambient conditions. For this purpose, we have provided sufficient data on somedrugs in the selected viscous and non-volatile solvents to support our claim.
Identification of the brands of the inkjet printers used in the altered document identification proficiency test: Combination of chemical analysis with conventional morphological examination
The altered document identification proficiency test of the China National Accreditation Service for Conformity Assessment (CNAS), initiated by the China Academy of Forensic Science in 2022, provided a specially prepared questioned document sample. This challenging case sample rendered conventional morphological examination methods virtually ineffective. As a result, only a low percentage of judicial appraisal institutions received the “satisfactory” rating. This work examined the characteristics of the inkjet printers used in the proficiency test from two independent perspectives, by combining volatile solvent composition analysis of printing inks using GC–MS creatively with conventional morphological examination. This work not only efficiently determined whether there was appended content via a secondary printing pass in the case sample, but also further identified the brands of the inkjet printers used to prepare the sample of the proficiency test. Finally, precautions for identifying the brands of inkjet printers were summarized. We hope this work will underscore the importance of incorporating physical and chemical analytical methods in questioned document examination and draw forensic examiners’ attention to its necessity. •Presents results of China Academy of Forensic Science 2022 altered document proficiency test.•Combined chemical and morphological analysis improves robustness.•GC–MS analysis of volatile solvents recommended and demonstrated.•Discusses limitations of morphological methods under current training system.
GC-MS Silylation Derivative Method to Characterise Black BIC® Ballpoint 2-Phenoxyethanol Ratio Evaporation Profile—A Contribution to Ink Ageing Estimation
One of the major challenges in forensic document analysis is estimating the age of ink deposition on a manually written document. The present work aims to develop and optimise a methodology, based on the evaporation of 2-phenoxyethanol (PE) over time, that can contribute to ink age estimation. A black BIC® Crystal Ballpoint Pen was purchased in a commercial area, and ink deposition began in September 2016 over 1095 days. For each ink sample, 20 microdiscs were subjected to n-hexane extraction in the presence of an internal standard (ethyl benzoate) followed by derivatisation with a silylation reagent. A gas chromatography-mass spectrometry (GC/MS) method was optimised for PE-trimethylsilyl (PE-TMS) to characterise the ageing curve. The developed method presented good linearity between 0.5 and 50.0 μg mL−1, as well as limits of detection and quantification of 0.026 and 0.104 μg mL−1, respectively. It was possible to characterise PE-TMS concentration over time, which reveals a two-phase decay behaviour. First, there was a substantial decline between the 1st and the 33rd day of deposition, followed a by a stabilisation of the signal, which allowed to detect the presence of PE-TMS up to 3 years. Two unknown compounds were also present and allowed to identify three dating time frames for the same ink stroke: (i) between time 0 and 33 days, (ii) between time 34 and 109 days, and (iii) more than 109 days. The developed methodology allowed to characterise the behaviour of PE over time and to establish a relative dating of three-time frames.
An Advanced Twin-Screw Granulation Technology: The use of Non-Volatile Solvents with High Solubilizing Capacity
Purpose Twin-screw wet granulation (TSWG) is a manufacturing process that offers several advantages for the processing of water-insoluble active pharmaceutical ingredients (APIs) and has been used for increasing the solubility and dissolution rates. Here we introduce a novel TSWG approach with reduced downstream processing steps by using non-volatile solvents as granulating binders. Methods Herein, TSWG was carried out using Transcutol a non-volatile protic solvent as a granulating binder and dissolution enhancer of ibuprofen (IBU) blends with cellulose polymer grades (Pharmacoat ® 603, Affinisol™, and AQOAT ® ). Results The physicochemical characterisation of the produced granules showed excellent powder flow and the complete transformation of IBU into the amorphous state. Dissolution studies presented immediate release rates for all IBU formulations due to the high drug-polymer miscibility and the Transcutol solubilising capacity. Conclusions Overall, the study demonstrated an innovative approach for the development of extruded granules by processing water-insoluble APIs with non-volatile solvents for enhanced dissolution rates at high drug loadings. Graphical Abstract
Study of ink aging: Targeting triethylene glycol in carbon-based black gel ink strokes on paper
[Display omitted] •More ink manufacturers in China use triethylene glycol as a solvent.•The evaporation of solvents in ink could be divided into three stages.•In the final stage, content of the solvent stop decreasing, producing a flat curve.•Estimating the writing age of gel ink in document by content of solvents. For the past decades, forensic chemists have made considerable efforts to develop methods capable of dating ballpoint pen ink by monitoring the loss of volatile solvents over time; however, few studies have been reported on carbon-based black gel inks. In China, carbon-based black gel pens are typically used for formal writing and signatures, such as contracts, loan receipts, testaments, and paper tests. Thus, it is imperative to analyze the age of carbon-based black gel inks for questioned document examiners in forensic casework. In this study, by employing the combination of gas chromatography with mass spectrometry (GC–MS) and GC with a flame ionization detector, a useful method for ink dating was proposed according to the dissipation of triethylene glycol from three novel carbon-based black gel inks. The ink aging curves suggested that this approach can distinguish questioned ink samples that are less than or greater than 9 months. This result could help to identify some questioned documents actually written within a month but are passed off as documents written years ago.
In Vitro Release, Mucosal Permeation and Deposition of Cannabidiol from Liquisolid Systems: The Influence of Liquid Vehicles
This work investigated the influence of liquid vehicles on the release, mucosal permeation and deposition of cannabidiol (CBD) from liquisolid systems. Various vehicles, including EtOH, nonvolatile low- and semi-polar solvents, and liquid surfactants, were investigated. The CBD solution was converted into free-flowing powder using carrier (microcrystalline cellulose) and coating materials (colloidal silica). A physical mixture of the CBD and carrier–coating materials was prepared as a control. The non-crystalline state of CBD in the liquisolid systems was confirmed using XRD, FTIR and SEM studies. The CBD liquisolid powder prepared with volatile and nonvolatile solvents had a better CBD release performance than the CBD formed as the surfactant-based and control powders. The liquisolid systems provided the CBD permeation flux through porcine esophageal mucosa ranging from 0.68 ± 0.11 to 13.68 ± 0.74 µg·cm−2·h−1, with the CBD deposition levels of 0.74 ± 0.04 to 2.62 ± 0.30 μg/mg for the dry mucosa. Diethylene glycol monoethyl ether showed significant CBD permeation enhancement (2.1 folds) without an increase in mucosal deposition, while the surfactants retarded the permeation (6.7–9.0 folds) and deposition (1.5–3.2 folds) significantly. In conclusion, besides the drug release, liquid vehicles significantly influence mucosal permeation and deposition, either enhanced or suppressed, in liquisolid systems. Special attention must be paid to the selection and screening of suitable liquid vehicles for liquisolid systems designed for transmucosal applications.
Improved stability of highly concentrated LiBF4/fluorinated ethyl acetate-based electrolyte solutions with a co-solvent for LiNi0.8Co0.1Mn0.1O2 positive electrodes in lithium ion batteries
AbstractA nearly saturated 2,2,2-trifluoroethyl acetate (FEA)-based electrolyte solution has a low viscosity and delivers superior charge/discharge performance for LiNi0.8Co0.1Mn0.1O2 (NCM811) positive electrodes for lithium ion batteries. However, FEA has a low flash point, and hence needs to be mixed with an appropriate co-solvent to improve the safety of electrolyte solutions. In this study, two kinds of co-solvent were introduced into LiBF4/FEA electrolyte solutions and the LiBF4 concentration was increased. The mixture ratio of FEA and a co-solvent had a major effect on the charge/discharge performance of NCM811. The resultant nearly saturated electrolyte solution further improved the charge/discharge properties in terms of both cycle- and high rate performance. A very thin protective layer formed on NCM811 to suppress continual decomposition of the electrolyte solution, and did not interfere with interfacial Li+ transfer between the NCM811 electrode and electrolyte solution. In addition, 2,2-difluoroethyl acetate, which has a higher flash point than FEA, was used as a main solvent to study the highly concentrated electrolyte solutions.Graphic abstract
From Benzos to Berries: Treatment Offered at an Aboriginal Youth Solvent Abuse Treatment Centre Relays the Importance of Culture
First Nations and Inuit youth who abuse solvents are one of the most highly stigmatized substance-abusing groups in Canada. Drawing on a residential treatment response that is grounded in a culture-based model of resiliency, this article discusses the cultural implications for psychiatry's individualized approach to treating mental disorders. A systematic review of articles published in The Canadian Journal of Psychiatry during the past decade, augmented with a review of Canadian and international literature, revealed a gap in understanding and practice between Western psychiatric disorder–based and Aboriginal culture–based approaches to treatment and healing from substance abuse and mental disorders. Differing conceptualizations of mental health and substance abuse are discussed from Western psychiatric and Aboriginal worldviews, with a focus on connection to self, community, and political context. Applying an Aboriginal method of knowledge translation—storytelling—experiences from front-line workers in a youth solvent abuse treatment centre relay the difficulties with applying Western responses to Aboriginal healing. This lends to a discussion of how psychiatry can capitalize on the growing debate regarding the role of culture in the treatment of Aboriginal youth who abuse solvents. There is significant need for culturally competent psychiatric research specific to diagnosing and treating First Nations and Inuit youth who abuse substances, including solvents. Such understanding for front-line psychiatrists is necessary to improve practice. A health promotion perspective may be a valuable beginning point for attaining this understanding, as it situates psychiatry's approach to treating mental disorders within the etiology for Aboriginal Peoples.
The effect of adolescent inhalant abuse on energy balance and growth
The abuse of volatile solvents such as toluene is a significant public health concern, predominantly affecting adolescents. To date, inhalant abuse research has primarily focused on the central nervous system; however, inhalants also exert effects on other organ systems and processes, including metabolic function and energy balance. Adolescent inhalant abuse is characterized by a negative energy balance phenotype, with the peak period of abuse overlapping with the adolescent growth spurt. There are multiple components within the central and peripheral regulation of energy balance that may be affected by adolescent inhalant abuse, such as impaired metabolic signaling, decreased food intake, altered dietary preferences, disrupted glucose tolerance and insulin release, reduced adiposity and skeletal density, and adrenal hypertrophy. These effects may persist into abstinence and adulthood, and the long‐term consequences of inhalant‐induced metabolic dysfunction are currently unknown. The signs and symptoms resulting from chronic adolescent inhalant abuse may result in a propensity for the development of adult‐onset metabolic disorders such as type 2 diabetes, however, further research investigating the long‐term effects of inhalant abuse upon energy balance and metabolism are needed. This review addresses several aspects of the short‐ and long‐term effects of inhalant abuse relating to energy and metabolic processes, including energy balance, intake and expenditure; dietary preferences and glycemic control; and the dysfunction of metabolic homeostasis through altered adipose tissue, bone, and hypothalamic‐pituitary‐adrenal axis function.