A preliminary study on electrochemical biosensors for the determination of total cholinesterase inhibitors in strawberries

2007 ◽  
Vol 87 (10-11) ◽  
pp. 689-699 ◽  
Author(s):  
Walter Vastarella ◽  
Vito Rosa ◽  
Carlo Cremisini ◽  
Livia Della Seta ◽  
Maria Rita Montereali ◽  
...  
2013 ◽  
Vol 89 ◽  
pp. 549-554 ◽  
Author(s):  
Chong Sun ◽  
Jingjing Miao ◽  
Jie Yan ◽  
Kai Yang ◽  
Chun Mao ◽  
...  

Author(s):  
Yan Xiong ◽  
Yong-Hong Liu ◽  
Jian-Sha Li ◽  
Yu-Ying Zhang ◽  
Jing Zhang ◽  
...  

Abstract A simple high performance liquid chromatography (HPLC) method was developed and validated for the determination of coumarin-3-carboxylic acid analogues (C3AA) in rat plasma and a preliminary study on pharmacokinetics. Ferulic acid (FA) was used as the internal standard substance, and coumarin-3-carboxylic acid (C3A) was used as a substitute for quantitative C3AA. After protein precipitation with methanol, the satisfactory separation was achieved on an ODS2 column when the temperature was maintained at 30 ± 2°C. The correlation coefficient r in the C3A linear equation is equal to 0.9990. Pharmacokinetic parameters for t1/2, Tmax, Cmax, area under the curve (AUC)0-t, average residence time (MRT), apparent volume of distribution (V z/F) and clearance (Cl/F) were 1.89 ± 0.03 h, 0.39 ± 0.14 h, 1.81 ± 0.10 g· mL−1 ·h, 7.88 ± 0.24 g·mL−1·h, 3.23 ± 0.14 h, 0.43 ± 0.03 (mg·kg−1)·(g·mL−1)−1·h−1, respectively. The high performance liquid chromatography-photo diode array detector (HPLC-PDA) method established in this study can be used to separate and determine the content of C3AA in plasma of rats after 60% ethanol extraction by gavage. The plasma concentration-time curve and pharmacokinetic parameters reflect the absorption of C3AA in rat blood after oral administration to some extent.


1991 ◽  
Vol 37 (4) ◽  
pp. 536-539 ◽  
Author(s):  
Catherine Harthé ◽  
Bruno Claustrat ◽  
Jocelyne Brun ◽  
Guy Chazot

Abstract We describe here a direct a radioimmunoassay (RIA) for the determination of 6-sulfatoxymelatonin (aMT6s) in plasma, with iodinated aMT6s as tracer. The aMT6s antiserum was raised in rabbit by immunization with a bovine serum albumin conjugate, giving negligible cross-reactivities for related compounds. The low limit of detection (15 pmol/L) allowed a direct assay that required only a 100-microL plasma sample. Dilutions of plasma and of synthetic aMT6s gave the same parallel response in the RIA. A preliminary study showed a circadian variation in healthy volunteers, with mean concentrations ranging from 52 (at 1600-2100 h) to 378 pmol/L (at 0400 h), whereas this rhythm was abolished in pinealomectomized patients. After administration of melatonin orally, or by infusion, the aMT6s concentrations in plasma concorded with previous data on aMT6s production and pharmacokinetics, with aMT6s being cleared from plasma more slowly than melatonin. This assay should have practical application in the development of new pharmaceutical formulations that minimize the hepatic metabolism of melatonin.


2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.


Author(s):  
Hana Mlejnkova ◽  
Katerina Sovova ◽  
Petra Vasickova ◽  
Vera Ocenaskova ◽  
Lucie Jasikova ◽  
...  

The virus SARS-CoV-2, which has caused the recent COVID-19 pandemic, may be present in the stools of COVID-19 patients. Therefore, we aimed to detect SARS-CoV-2 in wastewater for surveillance of SARS-CoV-2 in the population. Samples of untreated wastewater were collected from 33 wastewater treatment plants (WWTPs) of different sizes within the Czech Republic. SARS-CoV-2 RNA was concentrated from wastewater and viral RNA was determined using real-time reverse transcription polymerase chain reaction (RT-qPCR). SARS-CoV-2 RNA was detected in 11.6% of samples and more than 27.3% of WWTPs; in some of them, SARS-CoV-2 was detected repeatedly. Our preliminary results indicate that an epidemiology approach that focuses on the determination of SARS-CoV-2 in wastewater could be suitable for SARS-CoV-2 surveillance in the population.


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