Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-12-10
pubmed:abstractText
A new technique, based on the measurement of the phase angle of the photoacoustic signal, was used for investigating the absorption spectra of melanins in the dry state. The main advantages of such a method are the insensitivity to scattering of the light and the applicability to nontransparent or highly adsorbing and thermally thick samples. The spectra obtained on different kinds of natural and synthetic melanins show much more details than the corresponding ones obtained spectrophotometrically on aqueous suspensions of the pigment. Some relevant features of the spectra still cannot be interpreted, yet we were able to show the presence in eumelanins of dopachrome at 475 nm and melanochrome at 540 nm, and in pheomelanins of compounds previously isolated from red chicken feathers. Moreover, the well known trend of the optical absorption, i.e., its decrease with increasing wavelength, was unambiguously confirmed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0893-5785
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
140-4
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Application of photoacoustic phase angle spectroscopy (phi AS) to eumelanins and pheomelanins.
pubmed:affiliation
Department of Physics, University of Parma, Italy.
pubmed:publicationType
Journal Article, Comparative Study