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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 64(2): 448-53, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16434228

RESUMO

Raman spectroscopy has been used to investigate raw cotton acetylation using acetic anhydride/4-dimethylaminopyridine (DMAP) catalyst blend without solvent. The Raman data further confirm successful acetylation as shown by FTIR that was demonstrated previously to be highly sensitive for determining the level of acetylation. However, the Raman peaks are much weaker than the FTIR bands. Nevertheless, the variations of the extent of acetylation estimated from both Raman and FTIR spectra with weight percent gain due to acetylation (WPG) were observed to follow the same pattern. The degrees of acetylation calculated from Raman data were also found to increase linearly with that calculated from the more sensitive FTIR technique. Raman technique is thus suitable for further development as an analytical tool for determining the acetylation level of natural cellulose fibres. Raman data have also shown that the acetylation reaction reduces the crystallinity of cotton.


Assuntos
Fibra de Algodão , Análise Espectral Raman , Acetilação , Celulose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração
2.
Analyst ; 124(4): 553-60, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10605880

RESUMO

Various rice samples were collected in Vietnam from the Red River region, and some other parts of the country as well as from Yanco, NSW, Australia. The rice samples were analysed for 14 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Al, Na, Ni, As, Mo, and Cd) by ICP-AES, ICP-MS and FAAS. The analytical procedures were carefully controlled and validated using the rice flour certified material (NIES No 10). In general, the results showed that Vietnamese rice has elemental concentration ranges similar to those of the Australian and other overseas rice. However, analyses for some elements are characteristic of some Vietnamese and Australian rice samples. Thus, Vietnamese rice shows somewhat higher levels of P, K and Mg than rice samples from other countries; Mn could be a marker for the Australian rice grown in the Yanco region, and the analysed Australian samples were also very low in Cd (< 0.003 mg kg-1). An unusual distribution of Ni, present in higher concentrations in the white rice samples than in the brown ones, was observed for some Vietnamese rice samples.


Assuntos
Oryza/química , Oligoelementos/análise , Humanos , Vietnã
3.
Analyst ; 124(4): 561-9, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10605881

RESUMO

Rice samples were obtained from the Red River region and some other parts of Vietnam as well as from Yanco, Australia. These samples were analysed for 14 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Al, Na, Ni, As, Mo and Cd) by ICP-AES, ICP-MS and FAAS as described in Part 1. This data matrix was then submitted to multivariate data analysis by principal component analysis to investigate the influences of environmental and crop cultivation variables on the elemental content of rice. Results revealed that geographical location, grain variety, seasons and soil conditions are the most likely significant factors causing changes in the elemental content between the rice samples. To assess rice quality according to its elemental content and physio-biological properties, a multicriteria decision making method (PROMETHEE) was applied. With the Vietnamese rice, the sticky rice appeared to contain somewhat higher levels of nutritionally significant elements such as P, K and Mg than the non-sticky rice. Also, rice samples grown during the wet season have better levels of nutritionally significant mineral elements than those of the dry season, but in general, the wet season seemed to provide better overall elemental and physio-biological rice quality.


Assuntos
Oryza/química , Oligoelementos/análise , Meio Ambiente , Humanos , Análise Multivariada , Vietnã
4.
Analyst ; 123(4): 571-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9684399

RESUMO

The versatility of FTIR spectrometry was explored by considering a variety of samples drawn from industrial applications, materials science and biomedical research. These samples included polymeric insulators, bauxite ore, clay, human hair and human skin. A range of sampling techniques suitable for these samples is discussed, in particular FTIR microscopy, FTIR emission spectroscopy, attenuated total reflectance and photoacoustic FTIR spectrometry. The power of modern data processing techniques, particularly multivariate analysis, to extract useful information from spectral data is also illustrated.


Assuntos
Cabelo/química , Pele/química , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , Minerais/análise , Polímeros/análise , Protetores Solares/análise
5.
Pol Arch Med Wewn ; 90(1): 35-41, 1993 Jul.
Artigo em Polonês | MEDLINE | ID: mdl-8234003

RESUMO

The conduction of levels of glycosylated hemoglobin in patients with type II diabetes mellitus was studied A group of 111 ambulant patients was analyzed and special attention paid to those patients who were given the highest permissible oral dose. The dependence between the achieved glycosylation tests results and types of therapy, the clinical course of diabetes mellitus, as well as the conduction of results of standard compensation tests was analyzed. A lower correlation degree between the level of HbA1 and the results of standard compensation tests was indicated. At the same time a high correlation degree between HbA1 and clinically proven diabetes complication progress was observed. All achieved results suggest the usefulness of HbA1 determination in patients with type II diabetes mellitus suspected of incomplete compensation for instance treated highest permissible oral dose.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas/análise , Adulto , Idoso , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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