ISSN:
1618-2650
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Summary Zinc and copper metabolism became easier to study after science provided two research ways [1]: Isotope tracer technique and atomic absorption spectroscopy. Using stable isotopes is advantageous in humans because exposure to radioactivity is avoided and therefore the method can be used safely in infants and pregnant women. According to Ehrenkranz et al. [2, 3] zinc absorption in premature infants is 60%. Ziegler and coworkers report a lower absorption of zinc in infants (20%–44%) [8]. The copper intestinal uptake has been reported to be 68% in adults [3, 4]. We have investigated the bioavailability of zinc in a group of premature infants and one term infant weighing 1850 to 5630 g and the copper absorption in a man and an adolescent with M. Wilson (a copper storage disease) and discuss the accurate isotope analysis of human feces in relation to mineral bioavailability studies of premature infants. It is shown that for the determination of bioavailability of zinc and copper, the method of chelate-gas chromatography/mass spectrometry (GC/MS) is valuable for routine application to clinical experiments; the human fecal samples resulting from diet suitably enriched with isotopes68Zn,70Zn or65Cu can be routinely analysed with a precision of about 1% for these stable isotopes [2]. The total zinc in feces was determined by atomic absorption spectroscopy and the70Zn/64Zn ratio by chelate-GC/MS (EI). We have found different absorption values between 3% to 70% for zinc in a group of different infants including twins, triplets and preterms. The copper uptake was determined to be 79.7% and 49.9%.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01105167
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