Aggarwal S K, Kinter M, Wills M R, Savory J, Herold D A
Department of Pathology, University of Virginia Health Sciences Center, Charlottesville 22908.
Anal Chem. 1990 Jan 15;62(2):111-5. doi: 10.1021/ac00201a005.
An isotope dilution gas chromatography/mass spectrometry method using lithium bis(trifluoroethyl)dithiocarbamate as a chelating agent is described for the determination of chromium in urine. A wet digestion procedure with HNO3-H2O2 is used for oxidizing the organic matter associated with urine samples. The isotope ratios are measured by selected ion monitoring in a general-purpose mass spectrometer using a 10-m fused silica capillary column. Memory effect, in sequential analyses of samples with different isotope ratios, was evaluated by preparing a series of synthetic mixtures and was found to be negligible. The accuracy of the method was verified by quantitation of chromium in the NIST freeze-dried urine reference material, SRM-2670, with a recommended chromium concentration of 13 micrograms/L in the normal level and certified chromium concentration of 85 +/- 6 micrograms/L in the elevated level.
描述了一种使用双（三氟乙基）二硫代氨基甲酸锂作为螯合剂的同位素稀释气相色谱/质谱法，用于测定尿液中的铬。采用HNO₃-H₂O₂湿法消解程序氧化与尿液样品相关的有机物。在配备10米熔融石英毛细管柱的通用质谱仪中，通过选择离子监测来测量同位素比率。通过制备一系列合成混合物，评估了在连续分析具有不同同位素比率的样品时的记忆效应，发现其可忽略不计。通过对美国国家标准与技术研究院（NIST）冻干尿液标准物质SRM-2670中的铬进行定量，验证了该方法的准确性，正常水平下推荐的铬浓度为13微克/升，升高水平下认证的铬浓度为85±6微克/升。
