Turnlund J R
Sci Total Environ. 1983 Jun;28:385-92. doi: 10.1016/s0048-9697(83)80035-7.
Use of stable isotopes with analysis by thermal ionization mass spectrometry can determine trace element availability from dietary sources safely and with a high degree of accuracy. Stable isotopes of zinc (70Zn), copper (65Cu) and iron (58Fe) were fed with semipurified diets to humans. Excretion of isotopes was determined by isotope dilution in fecal composites collected for 15 days following the feedings. A thermal ionization, magnetic sector mass spectrometer was used to measure isotopic ratios. Total mineral content of fecal composites was determined by atomic absorption spectrophotometry. Mean absorption of zinc, iron and copper in six elderly men was 17.3, 8.7 and 26.0% respectively. Results agreed closely with absorption determined simultaneously in the same subjects using radioisotopes.
使用稳定同位素并通过热电离质谱分析法能够安全且高精度地测定膳食来源中微量元素的可利用性。将锌（70Zn）、铜（65Cu）和铁（58Fe）的稳定同位素与半纯化饮食一起喂给人类。在喂食后收集15天的粪便混合物，通过同位素稀释法测定同位素的排泄情况。使用热电离磁扇形质谱仪测量同位素比率。通过原子吸收分光光度法测定粪便混合物中的总矿物质含量。六名老年男性中锌、铁和铜的平均吸收率分别为17.3%、8.7%和26.0%。结果与使用放射性同位素在同一受试者中同时测定的吸收率非常吻合。
