An accurate and precise spectrofluorimetric method is presented for the determination of lisinopril based on the formation of a derivative formed with 7-chloro-4-nitrobenzofurazan. The derivatization reaction proceeds quantitatively at pH 8.5-9.0 and 60 degrees C in 70 min when the molar ratio of reagent to the drug is 170. After the extraction with ethyl acetate the fluorescence intensity of the derivative was measured at 528 nm with excitation at 465 nm. Calibration graph is rectilinear over the range of 50-1000 ng/ml with detection and determination limits of 20 and 50 ng/ml, respectively. The regression equation is I(f) = 0.198C-0.299 (r = 0.9999). The method was applied to the commercially available tablets and the results were statistically compared with those obtained by official HPLC method.
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http://dx.doi.org/10.1016/s0014-827x(02)00013-7 | DOI Listing |
Luminescence
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Two versatile yet simple methods, colorimetric and spectrofluorimetric, were utilized for the quantitation of nonchromophore neomycin using silver nanoparticles modified with fluorescein. Fluorescein was excited at 485 nm (emission at 515 nm); when it is deposited on the surface of silver nanoparticles, its fluorescence intensity at 515 nm is quenched. Neomycin restores the fluorescence level at 515 nm by displacing fluorescein from nanoparticle binding sites.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr Al-Aini Street, Cairo, 11562, Egypt.
Highly sensitive spectrofluorimetric methods were developed for the quantitative estimation of formoterol fumarate dihydrate (FFD) and fluticasone propionate (FP) in both authentic raw materials and marketed dosage forms using a micellar-enhanced spectrofluorimetric approach. The proposed methods are based on the determination of FP in the presence of FFD using the first derivative emission spectrofluorimetry. The peak amplitude of the emission spectra of the formed micellar fluorescence was measured at 465 nm after excitation at 236 nm (λ max of FP).
View Article and Find Full Text PDFBioanalysis
January 2025
Natural and Medical Sciences Research Center, University of Nizwa, Nizwa, Oman.
Aims: Gastrointestinal stromal tumors (GISTs) account for about 80% of the mesenchymal tumors of the GI tract. About 5000-6000 patients are diagnosed in the United States (US) alone, and up to 14.5 cases per million discovered in Europe annually.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.
Carbon quantum dots (CQDs) are a recently developed class of fluorescent nanoparticles made from carbon. Co-doping with heteroatoms such as nitrogen and sulfur improved the properties and generated a high quantum yield. In the proposed study, we utilized a simple, cost-effective, single-stage hydrothermal approach to produce extreme photoluminescence co-doped, nitrogen and sulfur, CQDs (N,S-CODs).
View Article and Find Full Text PDFJ Fluoresc
January 2025
Post-Graduate and Research Department of Chemistry, Government Arts College (Autonomous), Coimbatore, Tamil Nadu, 641 018, India.
An efficient probe (E)-2-(benzo[d]thiazol-2-yl)-3-(9-ethyl-9 H-carbazol-3-yl)acrylonitrile (CZ-BTZ) for selective fluorescence "turn-on" response with cyanide (CN) ion sensor was developed by simple Knoevenagel condensation of 9-ethyl-9 H carbazole-3-carbaldehyde with 2-(benzo[d]thiazol-2-yl) acetonitrile. The sensing ability of probe CZ-BTZ was tested with different inorganic anions through spectrophotometric and spectrofluorimetric methods. The UV-vis and fluorescence spectral studies show the formation of a new adduct between CZ-BTZ and CN by appearing with a new absorbance band at 350 nm and "turn-on" fluorescence at 535 nm in CHCN: HO (8:2, v/v, pH 7.
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