Searched for: author%3A%22Speek%2C+A.J.%22
(1 - 15 of 15)
document
Bloem, M.W. (author), Wedel, M. (author), van Agtmaal, E.J. (author), Speek, A.J. (author), Saowakontha, S. (author), Schreurs, W.H.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A group of 134 school children aged 3-9 y, with signs of conjunctival xerosis, from the rural area of Sakorn Nakhon province of Northeast Thailand were selected for a controlled study on the short-term effect (2 wk) of a single, oral high dose of vitamin A on iron metabolism. After collection of the baseline data, children within villages were...
article 1990
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Centraal Instituut voor Voedingsonderzoek TNO (author), Speek, A.J. (author)
doctoral thesis 1989
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Speek, A.J. (author), Temalilwa, C.R. (author), Schrijver, J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A fast and sensitive high-performance liquid chromatographic (HPLC) method for the determination of the provitamin A, ??-carotene, in vegetables is described. After alkaline saponification and organic extraction ??-carotene is separated from other carotenoids on a reversed-phase HPLC column and determined by measurement of its absorbance at 445...
article 1986
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Speek, A.J. (author), Thissen, J.T.N.M. (author), Schrijver, J. (author), Instituut CIVO-Toxicologie en voeding TNO (author)
The urinary excretion of 3-methylhistidine and creatinine and the urinary 3-methylhistidine to creatinine excretion ratio during day and night were investigated in a group of 103 healthy, normally fed Dutch children (52 boys and 51 girls) aged 2-17 years. The 3-methylhistidine to creatinine ratio of the night urine appeared to be significantly...
article 1986
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Speek, A.J. (author), van Agtmaal, E.J. (author), Saowakontha, S. (author), Schreurs, W.H.P. (author), van Haeringen, N.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A fast and sensitive high-performance liquid chromatographic (HPLC) method for the determination of vitamin A (all-trans retinol) in 50 ??l human tear fluid is described. After deproteinization with ethanol and extraction with n-hexane, retinol is separated from the extract on a straight-phase HPLC column and detected fluorometrically. Vitamin A...
article 1986
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Speek, A.J. (author), Wongkham, C. (author), Limratana, N. (author), Saowakontha, S. (author), Schreurs, W.H.P. (author), Instituut CIVO-Toxicologie en voeding TNO (author)
Chemicals/CAS: n,n dimethylacetamide, 127-19-5; retinol, 68-26-8, 82445-97-4; Vitamin A, 11103-57-4
article 1986
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Speek, A.J. (author), Schrijver, J. (author), Schreurs, W.H.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A high‐performance liquid chromatographic (HPLC) method is described for the simultaneous analysis of E vitamers α‐, and β‐, γ‐ and δ‐tocopherol and α‐tocotrienol in seed oils. After diluting the oils with n‐hexane, E vitamers are separated by HPLC and detected fluorometrically. Standardization is achieved, using electron‐impact mass...
article 1985
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Instituut CIVO-Toxicologie en Voeding TNO (author), Speek, A.J. (author), Schrijver, J. (author), Schreurs, W.H.P. (author)
A reliable and semi-automated high-performance liquid chromatographic (HPLC) method is described for the determination of total vitamin C in whole blood. After deproteinization of whole blood and enzymatic oxidation of l-ascorbic acid to dehydro-l-ascorbic acid, the latter is condensed with o-phenylenediamine to its quinoxaline derivative. This...
article 1984
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Instituut CIVO-Toxicologie en Voeding TNO (author), Speek, A.J. (author), Schrijver, J. (author), Schreurs, W.H.P. (author)
A reliable and sensitive high-performance liquid chromatographic (HPLC) method is described for the simultaneous determination of total vitamin C (l-ascorbic acid, AA, plus dehydro-1-ascorbic acid, DHAA) and its C-5 epimer, total isovitamin C (erythorbic acid, EA, plus dehydroerythorbic acid, DHEA), in foodstuffs and beverages. After extraction...
article 1984
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Centraal Instituut voor Voedingsonderzoek TNO (author), Speek, A.J. (author), Schrijver, J. (author), Schreurs, W.H.P. (author)
Chemicals/CAS: menadione sodium bisulfite, 130-37-0; menadione, 58-27-5; 2-methyl-1,4-dihydronaphthalene, 2717-43-3; Naphthalenes; Vitamin K 3, 58-27-5; Vitamin K, 12001-79-5.
article 1984
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Speek, A.J. (author), Odink, J. (author), Schrijver, J. (author), Schreurs, W.H.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A reliable high-performance liquid chromatographic method is presented for the determination of the urinary free catecholamines noradrenaline, adrenaline and dopamine. Urine is purified on a column of immobilized boric acid. Catecholamines are separated by ion-pair reversed phase high-performance liquid chromatography and detected...
article 1983
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Speek, A.J. (author), van Schaik, F. (author), Schrijver, J. (author), Schreurs, W.H.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A reliable high-performance liquid chromatographic (HPLC) method is developed for the analysis of FAD in whole blood of humans. The method is able to separate FAD, FMN and Rb from each other and from interfering compounds. A reliable and sensitive detection of FAD has been obtained by selecting the optimal pH of the mobile phase and optimal...
article 1982
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Centraal Instituut voor Voedingsonderzoek TNO (author), Schrijver, J. (author), Speek, A.J. (author), Klosse, J.A. (author), van Rijn, H.J.M. (author), Schreurs, W.H.P. (author)
A sensitive and reliable method for the determination of total thiamine (vitamin B1) in whole blood has been developed which is suited for routine analysis. After extraction, and enzymatic hydrolysis of thiamine phosphate esters, thiamine is separated from interfering compounds by a fully automated high-performance liquid chromatographic (HPLC)...
article 1982
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Feron, V.J. (author), Hendriksen, C.F.M. (author), Speek, A.J. (author), Til, H.P. (author), Spit, B.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)
A lifespan oral toxicity of vinyl chloride monomer (VCM) was carried out in Wistar rats, using five groups each of 60-80 males and 60-80 females. VCM was administered by incorporating polyvinyl chloride (PVC) powder with a high VCM content into the diet or by gastric intubation of a 10% VCM solution in soya-bean oil. The VCM doses (actual...
article 1981
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Centraal Instituut voor Voedingsonderzoek TNO (author), Leegwater, D.C. (author), Speek, A.J. (author)
Several hydroxypropyl oligoglucoses were detected in the faeces of rats on diets containing hydroxypropyl starches with degrees of substitution varying from 0.025–0.106. The major components were tentatively identified as hydroxypropylmaltose, dihydroxypropylmaltotriose, and dihydroxypropylmaltotetraose. The digestibility of the hydroxypropyl...
article 1972
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