scholarly journals Algorithms to optimize multi-column chromatographic separations of proteins

2021 ◽  
Vol 1637 ◽  
pp. 461838
Author(s):  
Santiago Codesido ◽  
Davy Guillarme ◽  
Szabolcs Fekete
1977 ◽  
Vol 54 (9) ◽  
pp. 564
Author(s):  
Ernest A. Dorko ◽  
William W. Baker

1963 ◽  
Vol 46 (4) ◽  
pp. 703-707
Author(s):  
George B Selzer ◽  
Daniel Banes

Abstract Sulfonamide drugs are recovered from milk by column chromatographic separations and determined colorimetrically by the Bratton-Marshall procedure. The sensitivity of the proposed method is about 0.1 ppm. Recoveries of individual sulfonamides from milk range between 60 and 91% at the 0.1—0.5 ppm level.


2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.


2020 ◽  
Vol 16 (3) ◽  
pp. 277-286
Author(s):  
Amal A. El-Masry ◽  
Mohammed E. A. Hammouda ◽  
Dalia R. El-Wasseef ◽  
Saadia M. El-Ashry

Background: The first highly sensitive, rapid and specific green microemulsion liquid chromatographic (MELC) method was established for the simultaneous estimation of fluticasone propionate (FLU) and azelastine HCl (AZL) in the presence of their pharmaceutical dosage form additives (phenylethyl alcohol (PEA) and benzalkonium chloride (BNZ)). Methods: The separation was performed on a C18 column using (o/w) microemulsion as a mobile phase which contains 0.2 M sodium dodecyl sulphate (SDS) as surfactant, 10% butanol as cosurfactant, 1% n-octanol as internal phase and 0.3% triethylamine (TEA) adjusted at pH 6 by 0.02 M phosphoric acid; with UV detection at 220 nm and programmed with flow rate of 1 mL/min. Results: The validation characteristics e.g. linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), accuracy, precision, robustness and specificity were investigated. The proposed method showed linearity over the concentration range of (0.5-25 µg/mL) and (0.1-25 µg/mL) for FLU and AZL, respectively. Besides that, the method was adopted in a short chromatographic run with satisfactory resolution factors of (2.39, 3.78 and 6.74 between PEA/FLU, FLU/AZL and AZL/BNZ), respectively. The performed method was efficiently applied to pharmaceutical nasal spray with (mean recoveries ± SD) (99.80 ± 0.97) and (100.26 ± 0.96) for FLU and AZL, respectively. Conclusion: The suggested method was based on simultaneous determination of FLU and AZL in the presence of PEA and BNZ in pure form, laboratory synthetic mixture and its combined pharmaceutical dosage form using green MELC technique with UV detection. The proposed method appeared to be superior to the reported ones of being more sensitive and specific, as well as the separation was achieved with good performance in a relatively short analysis time (less than 7.5 min). Highly acceptable values of LOD and % RSD make this method superior to be used in quality control laboratories with of HPLC technique.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 264
Author(s):  
Hawraz Ibrahim M. Amin ◽  
Faiq H. S. Hussain ◽  
Soran K. Najmaldin ◽  
Zaw Min Thu ◽  
Mohammed Farhad Ibrahim ◽  
...  

A dozen Iris species (Iridaceae) are considered traditional remedies in Kurdistan, especially for treating inflammations. Phytochemical studies are still scarce. The information reported in the literature about Iris species growing in Kurdistan has been summarized in the first part of this paper, although, except for Iris persica, investigations have been performed on vegetal samples collected in countries different from Kurdistan. In the second part of the work, we have investigated, for the first time, the contents of the methanolic extracts of Iris postii aerial parts and rhizomes that were collected in Kurdistan. Both extracts exhibited a significant dose-dependent free radical scavenging and total antioxidant activities, comparable to those of ascorbic acid. Medium-pressure liquid chromatographic separations of the two extracts afforded l-tryptophan, androsin, isovitexin, swertisin, and 2″-O-α-l-rhamnopyranosyl swertisin from the aerial parts, whereas ε-viniferin, trans-resveratrol 3,4′-O-di-β-d-glucopyranoside, and isotectorigenin were isolated from the rhizomes. This is the first finding of the last three metabolites from an Iris species. The various remarkable biological activities of isolated compounds scientifically sustain the traditional use of I. postii as a medicinal plant.


1973 ◽  
Vol 56 (3) ◽  
pp. 677-680
Author(s):  
F Raymond Fazzari

Abstract Chlorothiazide is eluted from a K2HPO4 column with acetic acid-ether solvent and extracted from the organic phase into HCl for the Spectrophotometric determination. Methyclothiazide and polythiazide are eluted from a NaHCO3 column with CHCl3 and measured directly. The method was collaboratively studied by 10 analysts. The average per cent recovered and standard deviations for preparations of chlorothiazide and methyclothiazide were 100.2±0.67 and 99.8±1.64, respectively. The method for chlorothiazide and methyclothiazide has been adopted as official first action.


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