Aggarwal S K, Kinter M, Herold D A
Department of Pathology, University of Virginia Health Sciences Center, Charlottesville 22908.
Anal Biochem. 1991 Apr;194(1):140-5. doi: 10.1016/0003-2697(91)90161-l.
A stable isotope dilution gas chromatography-mass spectrometry method using enriched 65Cu as an internal standard is described for the determination of Cu in urine and serum. Chelating agents N,N'-ethylenebis-(trifluoroacetylacetoneimine) [H2(enTFA2)] and lithium bis(trifluoroethyl)dithiocarbamate [Li(FDEDTC)] were used and evaluated for memory effect. H2(enTFA2) did not show any appreciable memory effect, whereas Li(FDEDTC) was found to have a strong memory effect. Overall precision of 1.6% was obtained for determining Cu isotope ratios at a 10-ng level using H2(enTFA2). Cu concentrations in the National Institute of Standards and Technology (NIST) reference materials, freeze-dried urine SRM 2670, and human serum SRM 909 determined using the H2(enTFA2) chelating agent were in good agreement with the NIST-certified values. Isotope ratios determined by gas chromatography-mass spectrometry on samples with altered isotopic composition were in good agreement with the inductively coupled plasma-mass spectrometry data.
描述了一种使用富集的⁶⁵Cu作为内标的稳定同位素稀释气相色谱 - 质谱法，用于测定尿液和血清中的铜。使用螯合剂N,N'-亚乙基双（三氟乙酰丙酮亚胺）[H₂(enTFA₂)]和双（三氟乙基）二硫代碳酸锂[Li(FDEDTC)]，并对记忆效应进行了评估。H₂(enTFA₂)未显示出任何明显的记忆效应，而Li(FDEDTC)被发现具有强烈的记忆效应。使用H₂(enTFA₂)在10 ng水平测定铜同位素比时，总体精密度为1.6%。使用H₂(enTFA₂)螯合剂测定的国家标准与技术研究院（NIST）参考物质、冻干尿液标准参考物质SRM 2670和人血清标准参考物质SRM 909中的铜浓度与NIST认证值高度一致。通过气相色谱 - 质谱法测定的同位素组成改变的样品的同位素比与电感耦合等离子体质谱数据高度一致。
