Serum cholinesterase activity was determined by conductimetry using samples in the microliter range. Butyrylcholine iodide was demonstrated to be a convenient substrate for the conductimetric assay. Validation of the microassay was made by using either purified enzyme or control serum. In the range of 0-60 U/l, a linear relationship was demonstrated. Correlation with a reference spectrophotometric method was obtained with a slope of 1.18. An explanation of this value is proposed, as different hydrolysis rates were obtained with human sera, depending on the substrate used (butyrylthio- or butyryl-choline ester).
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http://dx.doi.org/10.1159/000469015 | DOI Listing |
Chem Biodivers
June 2024
School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo, Lucano 10, Potenza, 85100, Italy.
New tranexamic acid (TXA) complexes of ferric(III), cobalt(II), nickel(II), copper(II) and zirconium(IV) were synthesized and characterized by elemental analysis (CHN), conductimetric (Λ), magnetic susceptibility investigations (μeff), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (H-NMR), ultraviolet visible (UV-vis.), optical band gap energy (E) and thermal studies (TG/DTG and DTA). TXA complexes were established in 1 : 2 (metal: ligand) stoichiometric ratio according to CHN data.
View Article and Find Full Text PDFAnal Bioanal Chem
September 2023
Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
Analyzing the composition of (human) urine plays a major role in the fields of biology and medicine. Organic molecules (such as urea, creatine) and ions (such as chloride, sulfate) are the major compounds present in urine, the quantification of which allows for the diagnosis of a subject's health condition. Various analytical methods have been reported for studying urine components and validated on the basis of known and referenced compounds.
View Article and Find Full Text PDFCrit Rev Anal Chem
September 2023
Normandie Univ, Laboratoire SMS-EA3233, FR3038 INC3M, UNIROUEN, Mont-Saint-Aignan, France.
For over 50 years, ion chromatography has been demonstrated to be a successful technique used to quantify a wide range of ions and ionizable compounds, either organic or inorganic, in various matrices using conductimetric or electrochemical detection. It was only since 1996 that ion chromatography was coupled to electrospray-mass spectrometry, opening the field to new applications in complex matrices and the detection of compounds at trace levels. This review covers the recent developments of ion exchange chromatography and mass spectrometry.
View Article and Find Full Text PDFInt J Biol Macromol
September 2021
School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China. Electronic address:
Fucan sulfates from echinoderm possess characteristic structures and various biological activities. Herein, comprehensive methods including enzymolysis, ion-exchange chromatography and size exclusion chromatography lead to the purification of five fucan sulfates (FSI, FSII, FSIII, FSIV, FSV) from the sea cucumber Pattalus mollis. Chemical composition analysis showed that they were all composed of l-fucose.
View Article and Find Full Text PDFAnalyst
February 2021
Institut de Chimie Organique et Analytique (ICOA), CNRS FR 2708 - UMR 7311, Université d'Orléans, 45067 Orléans, France.
The search for novel pancreatic lipase (PL) inhibitors has gained increasing attention in recent years. For the first time, a dual detection capillary electrophoresis (CE)-based homogeneous lipase assay was developed employing both the offline and online reaction modes. The hydrolysis of 4-nitrophenyl butyrate (4-NPB) catalyzed by PL into 4-nitrophenol and butyrate was monitored by spectrophotometric and conductimetric detection, respectively.
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