4 results match your criteria: "University of Sofia St. Kl. Ohridsky[Affiliation]"

The IR-spectroscopic properties of three esters of 1-coumarinylbenzylphosphonic acid are elucidated both in solution and in solid-state. Linear-polarized IR-spectroscopy of oriented colloid suspensions in nematic host is used for experimental IR-characteristic band assignment in solid-state. Theoretical quantum chemical DFT calculations at B3LYP level of theory and 6-31++G** basis set are carried.

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Determination of cephalosporins in solid binary mixtures by polarized IR- and Raman spectroscopy.

J Pharm Biomed Anal

September 2008

University of Sofia St. Kl. Ohridsky, Department of Analytical Chemistry, 1 J. Bourchier Boulevard, Sofia 1164, Bulgaria.

Quantitative IR- and Raman spectroscopic determinations of four cephalosporin antibiotics in six solid binary mixtures have been conducted. This is a new approach for spectroscopic determination of these antibiotics, since the corresponding quantitative analysis in solution only has been reported so far. The correlation coefficient r2 was found to be in the confidence intervals within 99.

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Gly-Pro-, Gly-Pro-Met- and Ala-Ala-Phe-N'-(2-hexyl-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)-hydrazides are synthesized by guanidinium/uronium type condensing reagent and used as fluorogenic substrates to localize dipeptidyl peptidase IV and tripeptidyl peptidase I activities in mammalian tissue sections. Enzyme hydrolysis releases 2-hexyl-6-hydrazino-1H-benzo[de]isoquinoline-1,3(2H)-dione, which couples with piperonal to form insoluble fluorescent hydrazone, precipitating on the enzyme locations and marking them. The fluorescent technique reveals precisely the enzymes locations at the lack of background noise in a single incubation step.

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Quantitative infrared (IR) and Raman spectroscopic approach for determination of phenacetin (Phen) and salophen (Salo) in binary solid mixtures with caffeine: phenacetin/caffeine (System 1) and salophen/caffeine (System 2) is presented. Absorbance ratios of 746 cm(-1) or 721 cm(-1) peaks (characteristic for each of determined compounds in the Systems 1 and 2) to 1509 cm(-1) and 1616 cm(-1) (attributed to Phen and Salo, respectively) were used. The IR spectroscopy gives confidence of 98.

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