Yergey A L
Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
J Nutr. 1996 Jan;126(1):355S-361S.
Thermal ionization mass spectrometry (TIMS) is the best of four currently used techniques for obtaining results of high accuracy and precision in studies of metal metabolism. TIMS is also the most general technique because it allows measurements of all the metallic elements of interest. The highest absolute sensitivity as well as the ability to determine multiple elements are simultaneously obtained with inductively coupled plasma mass spectrometry (ICP-MS). Current results with this technique show that, although element quantification may be done with acceptable accuracy and precision, use of ICP-MS in metabolic studies at low levels of isotopic labels may be limited. The most favorable elements for study using ICP-MS in metabolic studies appear to be Mg, Zn and possibly Fe. Use of this technique is limited further by isobaric interferences from plasma jet ion molecule reactions, and metabolic studies of Ca are particularly limited. Acceptable levels of accuracy and precision have been obtained from fast atom bombardment-secondary ion mass spectrometry (FAB-SIMS), which has allowed these approaches to be used in metabolic studies of ZN, Fe and Ca, but the approaches are ultimately limited by hydride isobaric interferences. Both FAB-SIMS and gas chromatography-mass spectrometry of metal chelates have the advantage of using widely available instrumentation. GC-MS of metal chelates has been shown to be useful in studies of Cr and Se metabolism and for the determination of a number of other metals. Values of accuracy and precision from use of this approach have been satisfactory.
热电离质谱法（TIMS）是目前用于金属代谢研究中获得高精度和高准确度结果的四种技术中最好的一种。TIMS也是最通用的技术，因为它可以测量所有感兴趣的金属元素。电感耦合等离子体质谱法（ICP-MS）同时具备最高的绝对灵敏度以及测定多种元素的能力。目前该技术的结果表明，尽管元素定量可以达到可接受的准确度和精密度，但在低水平同位素标记的代谢研究中使用ICP-MS可能会受到限制。在代谢研究中使用ICP-MS进行研究最有利的元素似乎是镁、锌，可能还有铁。该技术的使用还受到等离子体射流离子分子反应产生的同量异位素干扰的进一步限制，钙的代谢研究尤其受限。快速原子轰击-二次离子质谱法（FAB-SIMS）已获得可接受的准确度和精密度水平，这使得这些方法可用于锌、铁和钙的代谢研究，但这些方法最终受到氢化物同量异位素干扰的限制。FAB-SIMS和金属螯合物的气相色谱-质谱法都具有使用广泛可用仪器的优势。金属螯合物的气相色谱-质谱法已被证明在铬和硒代谢研究以及多种其他金属的测定中有用。使用这种方法获得的准确度和精密度值令人满意。
