Turnlund J R, Michel M C, Keyes W R, Schutz Y, Margen S
Am J Clin Nutr. 1982 Oct;36(4):587-91. doi: 10.1093/ajcn/36.4.587.
The apparent absorption of copper was determined in seven elderly men using the stable isotope 65Cu. Analysis of isotopic ratios of copper was done using thermal ionization, magnetic sector mass spectrometry after separation of copper from fecal samples by ion exchange chromatography. Mean apparent copper absorption during the first metabolic period in five men was 23.9 +/- 1.4% (mean +/- SEM) when fed a semipurified diet containing 3.3 mg of copper daily and 9 to 19 g nitrogen from egg albumin. Mean apparent copper absorption in five men during the second metabolic period was slightly but significantly higher, 27.7 +/- 0.31% (mean +/- SEM) when their diet contained 3.3 mg of copper per day and 4.0 to 5.7 g of nitrogen from egg albumin. The quantity of copper absorbed was equivalent to 0.8 mg per day in the first metabolic period and 0.9 mg during second metabolic period and was sufficient to maintain copper balance in these elderly men.
利用稳定同位素⁶⁵Cu测定了7名老年男性的铜表观吸收率。通过离子交换色谱法从粪便样本中分离出铜后，采用热电离磁扇形质谱法分析铜的同位素比率。5名男性在第一个代谢期，当食用每日含3.3毫克铜以及来自蛋清的9至19克氮的半纯化饮食时，平均铜表观吸收率为23.9±1.4%（平均值±标准误）。5名男性在第二个代谢期，当饮食中每日含3.3毫克铜以及来自蛋清的4.0至5.7克氮时，平均铜表观吸收率略高但显著升高，为27.7±0.31%（平均值±标准误）。第一个代谢期吸收的铜量相当于每天0.8毫克，第二个代谢期为0.9毫克，足以维持这些老年男性的铜平衡。
