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Título: METROLOGICAL EVALUATION OF SUNSCREENS BY LDI-TOF MASS SPECTROMETRY
Autor: JORGE MARCIAL AGUERO ANDRADE
Colaborador(es): CASSIA RIBEIRO PONCIANO - Orientador
Catalogação: 01/NOV/2018 Língua(s): PORTUGUESE - BRAZIL
Tipo: TEXT Subtipo: THESIS
Notas: [pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
[en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio.
Referência(s): [pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=35485&idi=1
[en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=35485&idi=2
DOI: https://doi.org/10.17771/PUCRio.acad.35485
Resumo:
Several studies of research note the obvious correlation between excessive exposure to sunlight, and the incidence of skin cancer, cataracts and premature aging of the skin. The market for cosmetics for sun protection is in the booming; various countries adopt laws specific to these products. In Brazil they are regulated by the National Sanitary Surveillance Agency (ANVISA). However, there are no official methods of chemical analysis to determine solar filters in cosmetics. In this work was developed a procedure for qualitative analysis of commercial cosmetics with solar filters by mass spectrometry LDI-TOF (Laser Desorption Ionization - Time-of-Flight). LDI technique uses a beam of monochromatic laser light, Lambda = 337 nm, as a probe to excite, desorbs and ionize the analyte. Although the spectrum of solar radiation is continuous, the wavelength used in LDI is well on the average range of radiation that includes UVA and UVB, which makes technical LDI potentially suitable to excite molecules of active substances similarly to lightning Sun. For such characteristics, it is reasonable to expect that LDI be selective to detect solar filters presents on cosmetics products. In parallel, was also used mass spectrometry (252)Cf-PDMS (Plasma Desorption Mass Spectrometry), which uses fragments of the fission of radioactive nuclide californium 252 instead of laser. Mass spectra were obtained from positive and negative ions, eight commercial cosmetics by both techniques, and PDMS spectra of active substances allowed by ANVISA. Masses observed on LDI mass spectra from selected products were compared with: i) molecular masses of all active substances allowed; ii) masses observed on PDMS mass spectra from standards allowed and commercial cosmetics; iii) molecular masses of sunscreens in its labels. The selectivity of the LDI technique to identify solar filters in cosmetics was demonstrated by mass spectra of positive and negative ions of the eight samples.
Descrição: Arquivo:   
COVER, ACKNOWLEDGEMENTS, RESUMO, ABSTRACT, SUMMARY AND LISTS PDF    
CHAPTER 1 PDF    
CHAPTER 2 PDF    
CHAPTER 3 PDF    
CHAPTER 4 PDF    
CHAPTER 5 PDF    
CHAPTER 6 PDF    
REFERENCES, APPENDICES PDF