scholarly journals Оптимізація аналітичного контролю залишкових кількостей фунгіцидів цифлуфенаміду та дифеноконазолу у воді

2018 ◽  
Author(s):  
P. V. Stavnichenko ◽  
A. M. Antonenko ◽  
O. P. Vavrinevych ◽  
A. V. Stetsenko ◽  
S. T. Omelchuk. ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Water Samples ◽  
Analytical Determination ◽  
Gas Liquid Chromatography ◽  
Ecological Significance ◽  
Application Rates ◽  
The Cost ◽  
New Compounds ◽  
Active Substances

Introduction. Annually, the assortment and application rates of pesticides are supplemented with new compounds of various chemical classes. Methods for the determination of active substances in water by the method of gas-liquid chromatography are known to provide for the determination of only one fungicide, which is quite costly. Therefore, it remains an actual goal to develop a method that will simultaneously identify different substances in one sample. Such a technique allows significantly increasing the speed of one definition and reducing the cost of conducting it. Such a method has not only economic but also ecological significance, since it can be effectively used for monitoring environmental studies.The aim of the study – to development a technique for the analytical determination of cyflufenamide and difenoconazole microquantities in water simultaneously.Research Methods. Research includes extraction, concentration and chromatography of prepared water samples. The quantitative determination of cyflufenamide and difenoconazole was carried out by gas-liquid chromatography using an electron-capture detector.Results and Discussion. The best result of active substances extraction from water samples was achieved using chloroform as an extractant. Chromatography conditions were established under which the retention time is: for cyflufenamide – 3.19 minutes; difenoconazole – 12.58 minutes. Limit of the quantification of this method for cyflufenamide is 0.001 mg/dm3, difenoconazole – 0.001 mg/dm3.Conclusions. The conditions for simultaneous determination of cyflufenamide and difenoconazole by the method of gas-liquid chromatography are developed with their simultaneous presence in the water sample, which allows significantly speeding up the analysis and reducing the cost of conducting it.

scholarly journals Residual amounts of pesticides in citrus fruits: analytical control

2021 ◽  
Vol 100 (5) ◽  
pp. 476-481
Author(s):  
Valery N. Rakitskii ◽  
Nataliia E. Fedorova ◽  
Marina S. Grechina ◽  
Olga E. Egorchenkova ◽  
Natalya A. Stepanova
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Group Method ◽  
Gas Liquid Chromatography ◽  
Citrus Fruits ◽  
Toxic Metabolites ◽  
Modern Development ◽  
Wide Range ◽  
Active Substances

Introduction. Thanks to possessing beneficial properties and vitamin content, citrus fruits occupy a prominent place in the ubiquitous nutrition of all ages due to various crops. On the other hand, due to climatic conditions, they cannot be cultivated in our country and are classified as imported products, which justifies the importance of controlling their safety. Purpose of the work. The creation of a multicomponent method for determining the residual amounts of pesticides and their metabolites in citrus fruits. Materials and methods. HPLC with triple quadrupole mass detector in multiple reaction monitoring (MRM) mode and capillary gas-liquid chromatography with mass selective detector (GC-MC) in selected ion monitoring mode (SIM) together were used to perform the identification and quantitative determination of the active substances of pesticides of various classes (amino pyrimidines, imidazoles, carbamates, strobilurins, triazoles, organophosphorus compounds, etc.) As a sample preparation method, there was used the QuEChERS technology, based on the extraction of pesticides with an organic solvent from a homogenized sample in the presence of salts containing citrate buffer and the purification of the extracts by dispersive solid-phase extraction. Results. To control the safety of citrus fruits (lemons, grapefruits, oranges, tangerines) imported from Egypt, Turkey and Abkhazia, purchased on the food market, a multi-method was used for determining the residual amounts of a wide range of pesticide compounds (50 names of active ingredients of pesticides and their toxic metabolites) in citrus fruits. The identified levels of active pesticide ingredients did not exceed the established MRLs. Conclusion. The modern development of the analytical chemistry of pesticides, the use of a tandem of gas and liquid chromatography with mass spectrometric detection made it possible to implement a group method for the quantitative determination of the active substances of pesticides and their toxic metabolites in citrus fruits. Modern development makes it possible to detect the contamination of their residual amounts in the processed products.

GASCHROMATOGRAPHIC DETERMINATION OF STEROIDS IN THE URINE OF PATIENTS WITH CUSHING'S SYNDROME

1971 ◽  
Vol 67 (2) ◽  
pp. 303-315 ◽  
Author(s):  
A. J. Moolenaar ◽  
A. P. van Seters
Keyword(s):  
Liquid Chromatography ◽  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Diagnostic Value ◽  
Cushing's Syndrome ◽  
Gas Liquid Chromatography ◽  
Obese Subjects

ABSTRACT The 17-oxosteroids were estimated in the urine of 27 patients with Cushing's syndrome by gas-liquid chromatography (G. L. C.). The values of the various steroid fractions are compared with those of normal subjects, patients with thyrotoxicosis and obese subjects. The effect of the age of the patients on the diagnostic value of the invidual 17-oxosteroids and their ratios is discussed.

Simultaneous Determination of Lactulose and Mannitol in Urine of Burn Patients by Gas-Liquid Chromatography

1992 ◽  
Author(s):  
Ronald L. Shippee ◽  
Avery A. Johnson ◽  
William G. Cioffi ◽  
James Lasko ◽  
Thomas E. LeVoyer
Keyword(s):  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
Gas Liquid Chromatography ◽  
Burn Patients

scholarly journals Gas Chromatographic Determination of Traces of Accelerants in Physical Evidence

1972 ◽  
Vol 55 (4) ◽  
pp. 840-845 ◽  
Author(s):  
Charles R Midkiff ◽  
Willard D Washington
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Vapor Phase ◽  
Selection Criteria ◽  
Chromatographic Determination ◽  
Operating Parameters ◽  
Gas Liquid Chromatography ◽  
Internal Standards ◽  
Physical Evidence

Techniques developed for use with gas-liquid chromatography for the examination of evidence collected at the scene of suspected arson fires and firebombings are discussed. Both solvent extraction and vapor phase examinations are employed. Internal standards are used for the identification of specific components in actual samples to allow confirmation of hydrocarbon type, e.g., gasoline and kerosene. Operating parameters and solvent selection criteria are included. Results obtained from known materials and residual hydrocarbons in actual samples are compared.

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