59 research outputs found
The Ability of Narcotic Detection Canines to Detect Illegal Synthetic Cathinones (Bath Salts)
Twelve certified narcotic detection canines were tested for their ability to detect confiscated illegal synthetic cathinones (bath salts). These canine teams were randomly assigned to two different groups and each group imprinted on one of two types of bath salts, ethylone and alpha-pyrrolidinovalerophenone (α-PVP), over the period of 1 month; while simultaneously documenting the imprinting procedure. The newly imprinted canines were validated by field testing and found to not only detect the imprinted bath salt to which they were trained, but they were able to detect other bath salts. The imprinting procedure and results are the first scientifically validated studies on the ability of canines to detect these harmful and illegal substances. Analytical headspace analysis using Solid Phase Microextraction (SPME) on several ethylone and α-PVP samples revealed compounds common in both. These compounds can be used to create a safe and reliable synthetic cathinone mimic training aid for canine teams
Silicon Nanoparticles: Source of Extended Red Emission?
We have reviewed the characteristics of the extended red emission (ERE) as
observed in many dusty astronomical environments, in particular, the diffuse
interstellar medium of the Galaxy. The spectral nature and the photon
conversion efficiency of the ERE identify the underlying process as highly
efficient photoluminescence by an abundant component of interstellar dust. We
have compared the photoluminescence properties of a variety of carbon- and
silicon-based materials proposed as sources for the ERE with the
observationally established constraints. We found that silicon nanoparticles
provide the best match to the spectrum and the efficiency requirement of the
ERE. If present in interstellar space with an abundance sufficient to explain
the intensity of the ERE, silicon nanoparticles will also contribute to the
interstellar 9.7 micron Si-O stretch feature in absorption, to the near- and
mid-IR nonequilibrium thermal background radiation, and to the continuum
extinction in the near- and far-UV. About 36% of the interstellar silicon
depleted into the dust phase would be needed in the form of silicon
nanoparticles, amounting to less than 5% of the interstellar dust mass. We
propose that silicon nanoparticles form through the nucleation of SiO in
oxygen-rich stellar mass outflows and that they represent an important
small-grain component of the interstellar dust spectrum.Comment: 5 pages; 1 included figure; accepted 1998 May 1, ApJ
Fabric phase sorptive extraction combined with high performance liquid chromatography for the determination of favipiravir in human plasma and breast milk
A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation pro-cedure, the herein assay shows a linear calibration curve over the range of 0.2-50 mu g/mL and 0.5-25 mu g/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 mu g/mL for plasma and 0.15 and 0.5 mu g/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration
Measuring Odor Transport of Narcotic Substances Using DART-MS
The employment of canines in matters of law enforcement is due to their heightened olfactory senses, which helps in evaluating the presence of illicit substances. However, there have been instances where canines are signaling the presence of narcotics when they are not there. This study aimed to analyze how active odorants transport from one area to another. Direct Analysis in Real-Time coupled to a high-resolution mass spectrometer (DART-MS) was used to analyze, in real-time, the volatile organic compounds (VOCs) of two narcotic substances: cocaine and methamphetamine. This study found that the transfer of VOCs from these narcotics does occur. Methyl benzoate was detected at 39.3 ± 3.2 s after exposure from 3 meters away, whereas benzaldehyde was detected at 43.3 ± 0.6 s from the same distance. The guidelines used for canine certification should be revisited to account for these results to lower or eliminate unconfirmed alerts by canines
Capsule Phase Microextraction Combined with Chemometrics for the HPLC Determination of Amphotericin B in Human Serum
This article discusses the use of a sorbent-based microextraction technique employing a capsule device to isolate amphotericin B (AMB) from human serum before analysis by high performance liquid chromatography (HPLC). AMB is a macrocyclic compound used for the treatment of invasive fungal infections. Before determining AMB in human serum by HPLC, a sample preparation step is required. Capsule phase microextraction (CPME) integrates the stirring and filtration mechanisms in a single unit, simplifying the sample preparation procedure. Moreover, it results in fast extraction kinetics and high extraction efficiency, while it has proved to be a powerful tool for bioanalysis. Different sol–gel sorbent encapsulated microextraction capsules were investigated, and sol–gel Carbowax 20 M was finally chosen as the basis for the microextraction device. Accordingly, the sample preparation protocol was investigated using a face-centered central composite design to achieve good extraction performance. The optimum protocol was validated in terms of linearity, selectivity, limit of detection (LOD), limit of quantitation (LOQ), precision, and accuracy. The linear range of the developed approach was 0.10–10.0 μg mL−1. The LOD value was 0.03 μg mL−1, and the LOQ value was 0.10 μg mL−1. Method accuracy (expressed as relative recovery) was 87–113%, while the relative standard deviation of the repeatability (sr) and within-laboratory reproducibility (sR) were <12.4%. The sol–gel sorbent encapsulated microextraction capsules were reusable for at least 10 extraction cycles. All things considered, the proposed method exhibited good overall performance, and it could be used in bioanalysis for quality control, therapeutic drug monitoring and research purposes
Capsule Phase Microextraction Combined with Chemometrics for the HPLC Determination of Amphotericin B in Human Serum
This article discusses the use of a sorbent-based microextraction technique employing a capsule device to isolate amphotericin B (AMB) from human serum before analysis by high performance liquid chromatography (HPLC). AMB is a macrocyclic compound used for the treatment of invasive fungal infections. Before determining AMB in human serum by HPLC, a sample preparation step is required. Capsule phase microextraction (CPME) integrates the stirring and filtration mechanisms in a single unit, simplifying the sample preparation procedure. Moreover, it results in fast extraction kinetics and high extraction efficiency, while it has proved to be a powerful tool for bioanalysis. Different sol–gel sorbent encapsulated microextraction capsules were investigated, and sol–gel Carbowax 20 M was finally chosen as the basis for the microextraction device. Accordingly, the sample preparation protocol was investigated using a face-centered central composite design to achieve good extraction performance. The optimum protocol was validated in terms of linearity, selectivity, limit of detection (LOD), limit of quantitation (LOQ), precision, and accuracy. The linear range of the developed approach was 0.10–10.0 μg mL−1. The LOD value was 0.03 μg mL−1, and the LOQ value was 0.10 μg mL−1. Method accuracy (expressed as relative recovery) was 87–113%, while the relative standard deviation of the repeatability (sr) and within-laboratory reproducibility (sR) were <12.4%. The sol–gel sorbent encapsulated microextraction capsules were reusable for at least 10 extraction cycles. All things considered, the proposed method exhibited good overall performance, and it could be used in bioanalysis for quality control, therapeutic drug monitoring and research purposes
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