scholarly journals Development, validation, and application of a new method for the quantitative determination of monohydrogen-substituted perfluoroalkyl carboxylic acids (H–PFCAs) in surface water

Chemosphere ◽  
2022 ◽  
Vol 287 ◽  
pp. 132143
Author(s):  
Mo Awchi ◽  
Wouter A. Gebbink ◽  
Bjorn J.A. Berendsen ◽  
Jonathan P. Benskin ◽  
Stefan P.J. van Leeuwen
1969 ◽  
Vol 62 (1_Suppl) ◽  
pp. S95-S112 ◽  
Author(s):  
A. H. W. M. Schuurs

ABSTRACT Various techniques for sensitising erythrocytes and latex particles with gonadotrophins, particularly with HCG, are described. The haemagglutination inhibition reactions are generally interpreted by means of »erythrocyte settling patterns«. By a new method of evaluating these patterns a relatively precise quantitative determination is possible. Latex agglutination inhibition reactions on slides are particularly suitable as rapid qualitative tests. In cases where the maximum attainable sensitivity of the agglutination inhibition tests is insufficient, e. g. for determining LH concentrations in urine, the hormone in the test fluid has to be concentrated or extracted. An alternative method is a modified haemagglutination inhibition test for large volumes which is applicable to unconcentrated urine. Due to non-specific inhibitions the above-mentioned tests cannot be applied to unprocessed serum. Agglutination inhibition tests with HCG are already well advanced, pregnancy diagnosis being their main application. Now that highly purified HCG is available, a satisfactory specificity for these tests can be attained. If the immune system for HCG is used for estimating LH, it has to meet additional specificity requirements. Furthermore, the measure of cross-reaction and the choice of standard merit special attention. Finally, a literature survey is given of test systems in which LH and FSH were used as antigens.


Author(s):  
Ruben Ashotovich Pogosyan ◽  
Olga Vladimirovna Nesterova ◽  
Dmitry Olegovich Bokov ◽  
Irina Alexandrovna Samylina

Objective: Pomegranate (Punica granatum L.) is a broadly used plant possessing a wide range of medicinal properties. In this research, we have mainly focused on the investigation of phenolic compounds of pomegranate fruit pulp (PFP).Methods: Fresh fruits of “Çəhrayı Gülöyşə,” “Kizil-anor,” and pomegranate varietal mixture were used as samples. High-performance liquid chromatography-ultraviolet (HPLC-UV) analysis of phenol carboxylic acids was performed with metal column Kromasil® C18 (4.6×250 mm, particle size 5 μm) and the acetonitrile-water-concentrated acid phosphoric system (400:600:5) under isocratic elution conditions (flow rate of 0.5 ml/min). Detection was carried out using a UV detector “GILSTON” UV/Visible model 151 at a wavelength of 280 nm.Results and Discussion: As a result of our research, we proposed chromatographic conditions for the separation of phenolic compounds, the conditions for sample preparation of PFP. Procedure for determination of phenolic carboxylic acids total content in terms of gallic acid by HPLC-UV method was developed. According to the obtained data, the content of phenolic carboxylic acids should be at least 0.7%.Conclusion: Procedure for the quantitative determination of gallic acid using the HPLC-UV method was developed. This method which can be used in the standardization of new medicinal plant raw materials - PFP, as well as extract preparations based on it in the future.


Author(s):  
Ruben Ashotovich Pogosyan ◽  
Olga Vladimirovna Nesterova ◽  
Dmitry Olegovich Bokov ◽  
Irina Alexandrovna Samylina

Objective: Pomegranate (Punica granatum L.) is a broadly used plant possessing a wide range of medicinal properties. In this research, we have mainly focused on the investigation of phenolic compounds of pomegranate fruit pulp (PFP).Methods: Fresh fruits of “Çəhrayı Gülöyşə,” “Kizil-anor,” and pomegranate varietal mixture were used as samples. High-performance liquid chromatography-ultraviolet (HPLC-UV) analysis of phenol carboxylic acids was performed with metal column Kromasil® C18 (4.6×250 mm, particle size 5 μm) and the acetonitrile-water-concentrated acid phosphoric system (400:600:5) under isocratic elution conditions (flow rate of 0.5 ml/min). Detection was carried out using a UV detector “GILSTON” UV/Visible model 151 at a wavelength of 280 nm.Results and Discussion: As a result of our research, we proposed chromatographic conditions for the separation of phenolic compounds, the conditions for sample preparation of PFP. Procedure for determination of phenolic carboxylic acids total content in terms of gallic acid by HPLC-UV method was developed. According to the obtained data, the content of phenolic carboxylic acids should be at least 0.7%.Conclusion: Procedure for the quantitative determination of gallic acid using the HPLC-UV method was developed. This method which can be used in the standardization of new medicinal plant raw materials - PFP, as well as extract preparations based on it in the future.


1943 ◽  
Vol 26 (3) ◽  
pp. 325-331 ◽  
Author(s):  
D. B. Zilversmit ◽  
C. Entenman ◽  
M. C. Fishler

1. A new method for the determination of an immediate precursor of a substance occurring in the animal body is presented. 2. Calculations on the quantitative determination of the rate of turnover of a substance and their application to experiments involving the use of labeling agents are given. These calculations take into account loss of the isotopic substance by way of breakdown or transport.


1987 ◽  
Vol 61 (4) ◽  
pp. 437-441 ◽  
Author(s):  
Yasuyuki TAKIGUCHI ◽  
Hiroshi YAMASHITA ◽  
Kazuhiro OHKOUCHI ◽  
Kenzo SHIMAHARA

2001 ◽  
Vol 30 (1) ◽  
pp. 37-52 ◽  
Author(s):  
J. Csapó ◽  
J. Schmidt ◽  
Zs. Csapó-Kiss ◽  
G. Holló ◽  
I. Holló ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Lianguo Chen ◽  
Bin Zhang ◽  
Jinlai Liu ◽  
Zhehua Fan ◽  
Ziwei Weng ◽  
...  

Background and Aims. The present study aimed to develop a simple and sensitive method for quantitative determination of monocrotaline (MCT) in mouse blood employing ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI/MS/MS) using rhynchophylline as an internal standard. Methods. Proteins present in the blood samples were precipitated using acetonitrile. MCT was separated using a 1.7-μm ethylene bridged hybrid (BEH) C18 column (2.1 mm × 50 mm) with a gradient elution program and a constant flow rate of 0.4 mL/min. The LC mobile phase consisted of 10 mmol/L ammonium acetate (containing 0.1% formic acid) and acetonitrile. The total elution time was 4.0 min. The analytes were detected on a UPLC-ESI mass spectrometer in multiple reaction monitoring (MRM) mode and quantified. Results. The new method for the determination of MCT has a satisfactory linear detection range of 1-2000 ng/mL and excellent linearity (r = 0.9971). The lower limit of quantification (LLOQ) of MCT is 1.0 ng/mL. Intra- and interassay precisions of MCT were ≤13% with an accuracy from 96.2% to 106.6%. The average recovery of the new method was >75.0%, and matrix effects were between 89.0% and 94.3%. Based on the pharmacokinetics data, the bioavailability of MCT in mice was 88.3% after oral administration. Conclusions. The results suggest that the newly standardized method for quantitative determination of MCT in whole blood is fast, reliable, specific, sensitive, and suitable for pharmacokinetic studies of MCT after intravenous or intragastric administration.


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