Equilibrio de fases em sistemas aquosos PEG/fosfato de potassio
AUTOR(ES)
Luiza Helena Meller da Silva
DATA DE PUBLICAÇÃO
1994
RESUMO
This work presents experimental equilibrium data. for two-phase polymer-salt aqueous systems. This is an important contribution to the study of partition of biomolecules. It is important to remind the lack of such data in the literature. The systems studied covers polyethilene glycol 8000 and 1000 plus potassium phosphate in water at a range of temperature and pH. Methods of analysis were:. potentiometric tritation for salt concentration and water content in a vacuum oven at 60° during 24 hours. Equation of Henderson-Haselbach was used for pH while temperature was maintained within +/- 0,1ºC. Results indicate an increase in the separation region caused by elevation of temperature and pH thus giving an higher difference in polymer concentration between phases. It must be enphasized that biomolecules parti tion coefficient is highly dependent on this concentration difference (tie line lenght). It was demonstrated that temperature affects phase equilibrium by changing the gradient of tie lines and moving the binodal curve thus affecting the separation region. the elevation of temperature increases the separation region and tie lines tend to higher gradients; the opposite is also verified. For proteins separation temperature is of paramount importance due to structure changes and denaturation. It was seen that temperature importance is higher in the 4°c - 25° C region as compared to 25°C - 40°C. Increasing the pH it was observed an increase both in the separation region and gradient of tie lines but little is known or reported in the literature about this topic. It was observed that at lower values of both temperature and pH a third phase (a solid one) was produced
ASSUNTO(S)
polietileno glicol fosfato de potassio regra das fases
ACESSO AO ARTIGO
http://libdigi.unicamp.br/document/?code=000080959Documentos Relacionados
- Caracterização e purificação da enzima bromelina em sistema de duas fases aquosas PEG/Fosfato
- Análise da viabilidade econômica da purificação da bromelina das folhas de curauá em sistema bifásico aquoso PEG/Fosfato
- Determinação de dados de equilíbrio de fases para sistemas aquosos com eletrólitos
- Caracterização e purificação da enzima bromelina derivada do curaua (Ananas erectifolius) em sistema bifasico aquoso PEG/fosfato
- Contribuições a modelagem do equilibrio de fases e da partição de moleculas biologicas em sistemas aquosos bifasicos