A rapid, reliable and rugged assay for determining codeine in human plasma using reversed-phase high-performance liquid chromatography with fluorescence detection was developed. This analytical method utilized an ion-exchange/mixed-mode solid-phase extraction procedure. The chromatographic separation was achieved using a 150 x 4.6 mm I.D., 3-microns reversed-phase C8 (deactivated for basic analytes) column at ambient temperature. Fluorescence detection (excitation at 214 nm and emission above 345 nm) for codeine and nalorphine allowed for a detectable limit of 5 ng/ml. The results showed that the method was linear from 10 to 300 ng/ml. The method had good reproducibility, precision, accuracy and recoveries of 91 and 90% for codeine and nalorphine, respectively. This method has been applied to study the pharmacokinetics of codeine in normal human subjects.
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http://dx.doi.org/10.1016/0021-9673(94)01212-w | DOI Listing |
Mikrochim Acta
January 2025
Guizhou Province, Qianzhi Mingguang Soaphorn Rice Processing Base, Zhijin County, Maochang Town, Bijie CityBijie City, 552103, China.
A smartphone-based non-invasive method was developed for salivary uric acid detection using Gleditsia Sinensis carbon dots (GS-CDs). The GS-CDs synthesized by the one-pot hydrothermal method emitted blue fluorescence at a maximum excitation wavelength of 350 nm and had good fluorescence stability in the presence of different ions, while showing selectivity to uric acid solution. The ability of uric acid (UA) to quench the fluorescent substances present in the GS-CDs, was confirmed through HPLC-FLD and LC-MS, FTIR and XPS.
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January 2025
School of Pharmacy, Lanzhou University, Lanzhou, 730000, P. R. China.
A novel analytical method was designed and developed that exhibited ultraviolet-visible (UV-Vis), fluorescence (FL), and resonance Rayleigh scattering (RRS) signals for straightforward and comprehensive determination of monoamine oxidase B (MAO-B) using polyethylenimine-functionalized silver nanoparticles (PEI-Ag NPs). Through a facile one-step experiment, and NaOH assisted, in an aqueous solution of 100 ℃ for 40 min PEI reacted with AgNO to generate PEI-Ag NPs with a yellow color and weak blue fluorescence. Interestingly, phenylacetaldehyde (PAA), a specific product of MAO-B, causes significant enhancement of the three optical signals of UV-Vis, FL, and RRS.
View Article and Find Full Text PDFMikrochim Acta
January 2025
School of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005, China.
A lanthanide ion-based metal-organic framework (Eu-TATAB nanorods) was designed and synthesized as an effective tri-mode nanoprobe for sensitive and portable detection of ethanol content in a water-ethanol mixture. The assay was based on the responsive properties of Eu-TATAB nanorods to ethanol stimulus and their adaptive encapsulation capability towards optically active lanthanides. With the addition of ethanol to the Eu-TATAB nanorods, the structure was destroyed, resulting in a decrease in luminescence, electrochemiluminescence, and ultraviolet-visible spectrophotometric signals by perturbing energy transfer in the Eu-TATAB nanorods.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
January 2025
Department of Hepatobiliary Surgery and Liver Transplantation Center, The Fifth Affiliated Hospital of Sun Yat-Sen University, 52 Mei Hua East Road, Zhuhai, 519000, China.
Purpose: Cancer-associated fibroblasts (CAFs) are the primary stromal component of the tumor microenvironment in hepatocellular carcinoma (HCC), affecting tumor progression and post-resection recurrence. Fibroblast activation protein (FAP) is a key biomarker of CAFs. However, there is limited evidence on using FAP as a target in near-infrared (NIR) fluorescence imaging for HCC.
View Article and Find Full Text PDFEur J Histochem
January 2025
Department of Critical Care Medicine, The Qujing No.1 People's Hospital, Qujing.
Intestinal barrier damage causes an imbalance in the intestinal flora and microbial environment, promoting a variety of gastrointestinal diseases. This study aimed to explore the mechanism by which adipose-derived stem cells (ADSCs) repair intestinal barrier damage. The human colon adenocarcinoma cell line Caco-2 and rats were treated with lipopolysaccharide (LPS) to establish in vitro and in vivo models, respectively, of intestinal barrier damage.
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