Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000600024 |
Resumo: | The acid-base constant of an anaesthetic drug, propofol, was determined in different acetonitrile-water mixtures by using multiwavelength spectrophotometric titration data. The pH values measured in acetonitrile-water mixtures with a glass electrode calibrated with an aqueous buffer, s w pH, were corrected to obtain s s pH, that is, the pH of the acetonitrile-water mixture as measured with a glass electrode calibrated with a buffer in the same solvent mixture. This last pH scale is directly related to the thermodynamic acid-base constant. The pKa value of propofol in pure water was found to be 11.67. Linear relationships were observed when the calculated pKa values of propofol in different solvent mixtures were plotted against the acetonitrile molar fraction. Also, a linear relationship was observed between pKa values and the reciprocal of the relative permittivity of the solvent mixture, 1/epsilon. This behavior was taken as indicative of the electrostatic nature of the ionization process. |
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Journal of the Brazilian Chemical Society (Online) |
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Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixturespropofolspectrophotometric titrationsacidity constantsolvent mixturesThe acid-base constant of an anaesthetic drug, propofol, was determined in different acetonitrile-water mixtures by using multiwavelength spectrophotometric titration data. The pH values measured in acetonitrile-water mixtures with a glass electrode calibrated with an aqueous buffer, s w pH, were corrected to obtain s s pH, that is, the pH of the acetonitrile-water mixture as measured with a glass electrode calibrated with a buffer in the same solvent mixture. This last pH scale is directly related to the thermodynamic acid-base constant. The pKa value of propofol in pure water was found to be 11.67. Linear relationships were observed when the calculated pKa values of propofol in different solvent mixtures were plotted against the acetonitrile molar fraction. Also, a linear relationship was observed between pKa values and the reciprocal of the relative permittivity of the solvent mixture, 1/epsilon. This behavior was taken as indicative of the electrostatic nature of the ionization process.Sociedade Brasileira de Química2005-10-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000600024Journal of the Brazilian Chemical Society v.16 n.5 2005reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532005000600024info:eu-repo/semantics/openAccessPissinis,DiegoSereno,Leónides E.Marioli,Juan M.eng2005-11-09T00:00:00Zoai:scielo:S0103-50532005000600024Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2005-11-09T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
title |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
spellingShingle |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures Pissinis,Diego propofol spectrophotometric titrations acidity constant solvent mixtures |
title_short |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
title_full |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
title_fullStr |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
title_full_unstemmed |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
title_sort |
Multi-wavelength spectrophotometric determination of propofol acidity constant in different acetonitrile-water mixtures |
author |
Pissinis,Diego |
author_facet |
Pissinis,Diego Sereno,Leónides E. Marioli,Juan M. |
author_role |
author |
author2 |
Sereno,Leónides E. Marioli,Juan M. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Pissinis,Diego Sereno,Leónides E. Marioli,Juan M. |
dc.subject.por.fl_str_mv |
propofol spectrophotometric titrations acidity constant solvent mixtures |
topic |
propofol spectrophotometric titrations acidity constant solvent mixtures |
description |
The acid-base constant of an anaesthetic drug, propofol, was determined in different acetonitrile-water mixtures by using multiwavelength spectrophotometric titration data. The pH values measured in acetonitrile-water mixtures with a glass electrode calibrated with an aqueous buffer, s w pH, were corrected to obtain s s pH, that is, the pH of the acetonitrile-water mixture as measured with a glass electrode calibrated with a buffer in the same solvent mixture. This last pH scale is directly related to the thermodynamic acid-base constant. The pKa value of propofol in pure water was found to be 11.67. Linear relationships were observed when the calculated pKa values of propofol in different solvent mixtures were plotted against the acetonitrile molar fraction. Also, a linear relationship was observed between pKa values and the reciprocal of the relative permittivity of the solvent mixture, 1/epsilon. This behavior was taken as indicative of the electrostatic nature of the ionization process. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-10-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000600024 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000600024 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532005000600024 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.16 n.5 2005 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318166589833216 |