Refractive index of dilute aqueous solution of polyvinyl alcohol

1958 ◽  
Vol 31 (122) ◽  
pp. 225-227 ◽  
Author(s):  
Masakazu Matsumoto ◽  
Yasuji Ohyanagi
2020 ◽  
Vol 16 (7) ◽  
pp. 867-871
Author(s):  
Harun Ergen ◽  
Muge Guleli ◽  
Cigdem Sener ◽  
Cem Caliskan ◽  
Sercan Semiz ◽  
...  

Introduction: Polyvinyl alcohol (PVA), a polymer, is in demand due to its usage in different applications such as pharmaceutical, biomedical and textile, paper, food industries. Methods: A new sensitive reversed phased high-pressure liquid chromatography (RP-HPLC) method with refractive index detector (RID) was developed for determination of PVA in an ophthalmic solution containing dexpanthenol and PVA as active substances and it was validated according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline. Results: Chromatographic separation was achieved on a Chiral-AGP (150 mm × 4.0 mm, 5 μm) column kept at 30°C with an isocratic flow at a flow rate of 1.0 ml/min. The detector temperature was 30°C, the retention time of PVA was around 1.0 min and the total run time was 5 minutes. Conclusion: The proposed method showed linearity, accuracy, precision, specificity, robustness, solution stability, and system suitability results within the acceptance criteria.


1968 ◽  
Vol 17 (3) ◽  
pp. 354-355 ◽  
Author(s):  
Atsushi MIZUIKE ◽  
Shigeki KANO

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.


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