Factors affecting the spectrophotometric determination of 2-oxo-3-deoxy-d-mannooctonic acid and 3,6-dideoxysugars in bacterial liposaccharides

1976 ◽  
Vol 12 (1) ◽  
pp. 73-74
Author(s):  
T. I. Burtseva ◽  
L. I. Glebko ◽  
Yu. S. Ovodov
Keyword(s):  
Spectrophotometric Determination ◽  
Factors Affecting

Optimization of the spectrophotometric determination of mercury using copper(II) diethanoldithiocarbamate

1985 ◽  
Vol 50 (8) ◽  
pp. 1661-1672 ◽  
Author(s):  
Ernest Beinrohr ◽  
Katarina Blazseková ◽  
Ján Garaj
Keyword(s):  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Ph Value ◽  
Rapid Determination ◽  
Analytical Signal ◽  
Aqueous Acetone ◽  
Determination Limit ◽  
Factors Affecting ◽  
Analytical Calibration

The work deals with the optimization of the conditions for the spectrophotometric determination of mercury using copper(II) diethanoldithiocarbamate [Cu((HOCH2CH2)2NCS2)2] (I). The determination is based on replacement of Cu2+ ions by Hg2+ ions in complex I in acidic aqueous acetone medium and measuring the decrease in the absorbance at the absorption maximum of complex I (λ = 440 nm). The statistical importance of the factors affecting the analytical signal (absorbance) was found by the analysis of variance. The analytical signal is affected most by the pH value, the concentration of Cu2+ ions, and the acetone content. The best results were obtained at pH ~ 2 and an acetone content of 15% (v/v). The analytical calibration curve is nonlinear. The determination limit is 50 μg Hg in 1 dm3. The method is useful for the rapid determination of mercury with a precision of ± 5% in colourless solutions not containing Cu2+ or Ag+ ions or strong oxidants.

Spectrophotometric Determination of the pK Values for Dissociation of the Sugar Hydroxyls in Pyrimidine Arabinonucleosides

1975 ◽  
Vol 30 (9-10) ◽  
pp. 565-570 ◽  
Author(s):  
Edward Darżynkiewicz ◽  
Henryk Sierakowski ◽  
David Shugar
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Titration ◽  
Factors Affecting ◽  
Alkyl Derivatives ◽  
Intramolecular Hydrogen

Arabinonucleosides, Spectrophotometric Titration, Sugar Hydroxyl Dissociation Spectrophotometric titration in the ultraviolet has been employed to determine the pK values for dissociation of the sugar hydroxyls in pyrimidine arabinonucleosides and some of their O′-methyl and O′-ethyl derivatives. The order of dissociation of the sugar hydroxyls in the arabinofuranose ring was 2′-OH > 3′-OH > 5′-OH. The higher acidity (lower pK) of the 2′-OH was interpreted in terms of formation of an intramolecular hydrogen bond of the form 5′-OH···2′-O(-) and the accompanying changes in conformation of the arabinose ring. The various factors affecting the dissociation of specific hydroxyls in some of the O′-alkyl derivatives are discussed in relation to steric, conformational and other effects.

Spectrophotometric Determination of Total Cr in Water

2018 ◽  
Author(s):  
Xhulieta Hamiti ◽  
Ilirjana Boci ◽  
Pranvera Lazo
Keyword(s):  
Spectrophotometric Determination

Modeling of dynamic mosaicism on ring chromosomes in human fibroblasts and IPSCS

2020 ◽  
pp. 12-13
Author(s):  
Т.В. Никитина ◽  
А.А. Кашеварова ◽  
М.М. Гридина ◽  
А.А. Хабарова ◽  
А.Г. Мензоров ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Human Fibroblasts ◽  
Cellular Heterogeneity ◽  
Mitotic Stability ◽  
Factors Affecting ◽  
Ring Chromosomes ◽  
Cell Clones ◽  
Mitotic Instability ◽  
Mitotic Behavior

Митотическая нестабильность кольцевых хромосом может приводить к появлению клеточных клонов с различной генетической структурой. В качестве модели нестабильности кольцевых хромосом в митозе мы использовали фибробласты от пациентов с r(8), r(13), r(18) и r(22) и полученные из них индуцированные плюрипотентные стволовые клетки (ИПСК). Линии ИПСК с r(22) имели относительно стабильный кариотип на протяжении десятков (до 60) пассажей и сохраняли неизменную структуру кольцевой хромосомы. Кариотип линий ИПСК с r(8) и r(18) на ранних пассажах стабильный, планируется его изучение на поздних пассажах. Наибольшее разнообразие кариотипа выявлено в линиях ИПСК с r(13), в которых наблюдали различные перестройки и выраженную клеточную гетерогенность. Определение факторов, влияющих на митотическую стабильность кольцевых хромосом, может иметь значение для консультирования пациентов. Mitotic instability of ring chromosomes can lead to the appearance of cell clones with different genetic structure. IPSCs from fibroblasts of patients with r(8), r(13), r(18), and r(22) were used as a model of ring chromosomes mitotic behavior. Karyotypes of iPSC lines with r(8) and r(18) have so far been evaluated only in the early passages, lines with r(22) have maintained a relatively stable karyotype up to 60 passages. The occurrence of rearrangements and cellular heterogeneity was found characteristic for r(13) iPSCs. The determination of factors affecting the ring chromosomes mitotic stability would be beneficial for the patient’s prognosis.

Spectrophotometric Determination Of Piroxicam In Tablets And Gel Forms

2017 ◽  
pp. 1
Author(s):  
Nabil Bader ◽  
Monia Almaghboub ◽  
Nessma Alshelmani
Keyword(s):  
Spectrophotometric Determination
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