Determination of ammonia, amides, and the degree of hydrolysis of partially hydrolyzed polyacrylamide by thermometric titration and direct injection enthalpimetry

1987 ◽  
Vol 111 ◽  
pp. 57-65 ◽  
Author(s):  
Lee D Hansen ◽  
Delbert J Eatough
Keyword(s):  
Direct Injection ◽  
Degree Of Hydrolysis ◽  
Partially Hydrolyzed Polyacrylamide ◽  
Thermometric Titration ◽  
Hydrolyzed Polyacrylamide ◽  
Hydrolysis Of

Polarographic study of hydrolysis of [8-lysine]vasopressin and its derivatives with blood serum of pregnant women

1980 ◽  
Vol 45 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Mikuláš Chavko ◽  
Michal Bartík ◽  
Evžen Kasafírek
Keyword(s):  
Blood Serum ◽  
Pregnant Women ◽  
Degree Of Hydrolysis ◽  
Polarographic Study ◽  
Ph Optimum ◽  
Lysine Vasopressin ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Vasopressin Analogues

A polarographic study of the hydrolysis of [8-lysine]vasopressin and some hormonogens of the vasopressin series with the blood serum of women in the last week of pregnancy was studied. The dependence of hydrolysis on pH (pH optimum: 7.4-7.50, substrate concentration (Km 1.2 . 10-5M), pH stability and thermal stability were determined. The rate of hydrolysis of individual vasopressin analogues decreases in the order: [8-lysine]vasopressin > Nα-glycyl-prolyl[8-lysine]-vasopressin > Nα-leucyl-[8-lysine]vasopressin > Nα-alanyl-[8-lysine]vasopressin > Nα-phenyl alanyl-[8-lysine]vasopressin > Nα-diglycyl-[8-lysine]vasopressin > Nα-prolyl-[8-lysine]vasopressin > Nα-triglycyl-[8-lysine]vasopressin > Nα-sarcosyl-glycyl-[8-lysine]vasopressin. The degree of hydrolysis gradually increases to a multiple with the length of the pregnancy in consequence of the presence of oxytocine. However, vasopressin is also hydrolysed to a small extent with the enzymes from the blood sera of non-pregnant women. Under similar analytical conditions oxytocin was not hydrolysed with the sera of non-pregnant women and therefore oxytocin is a more suitable substrate than vasopressin for polarographic determination of serum oxytocinase.

Determination of nonionic and partially hydrolyzed polyacrylamide molecular weight distributions using hydrodynamic chromatography

1986 ◽  
Vol 58 (11) ◽  
pp. 2242-2247 ◽  
Author(s):  
Martin A. Langhorst ◽  
Fredrick W. Stanley ◽  
Sergio S. Cutie ◽  
Jeffrey H. Sugarman ◽  
Larry R. Wilson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrodynamic Chromatography ◽  
Partially Hydrolyzed Polyacrylamide ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Hydrolyzed Polyacrylamide

Determination of partially hydrolyzed polyacrylamide in wastewater produced from polymer flooding by colloid titration

2013 ◽  
Vol 33 (4) ◽  
pp. 345-350
Author(s):  
Shenwen Fang ◽  
Ming Duan ◽  
Yini Xia ◽  
Hu Wang ◽  
Linyu Li
Keyword(s):  
Food Service ◽  
Polymer Flooding ◽  
Service Industries ◽  
Paper Making ◽  
Partially Hydrolyzed Polyacrylamide ◽  
Hydrolysis Degree ◽  
Colloid Titration ◽  
Materials Used ◽  
Hydrolyzed Polyacrylamide

Abstract Colloid titration has been widely used to determine the charge carried by macromolecules and the concentration of anionic and cationic polyelectrolytes in paper making and food service industries. This method is simple and the materials used are non-volatile and harmless, but it has not previously been used to determine the partially hydrolyzed polyacrylamide (HPAM) in wastewater produced from polymer flooding. In this paper, colloid titration was used to determine the HPAM in wastewater produced from polymer flooding in an oilfield. When the HPAM concentration (Cp) was <200 mg/l, the relationship between the Cp and the titration value (Vp) was linear. This linear relationship was influenced by the pH of wastewater and the hydrolysis degree of HPAM; Vp increased with the pH and the hydrolysis degree. However, it was independent of the concentration of solubilized crude oil and salt concentration in the wastewater and the molecular weight of the HPAM. Recovery tests showed that the determination of HPAM in the wastewater by colloid titration was reliable. It was also found that the colloid titration and starch iodide method had similar accuracies for determination of the HPAM and that colloid titration was a better method for the analyst.

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