A Method for the Quantitative Analysis of Iron Speciation in Meat by Using a Combination of Spectrophotometric Methods and High-Performance Liquid Chromatography Coupled to Sector Field Inductively Co

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• 作者：C. F. Harrington ; S. Elahi ; S. A. Merson ; and P. Ponnampalavanar
• 刊名：Analytical Chemistry
• 出版年：2001
• 出版时间：September 15, 2001
• 年：2001
• 卷：73
• 期：18
• 页码：4422 - 4427
• 全文大小：56K
• 年卷期：v.73,no.18(September 15, 2001)
• ISSN：1520-6882

文摘

The determination of the heme and non-heme iron fractions in raw and cooked beef steak by using spectrophotometric methods and high-performance liquid chromatography coupled to a double-focusing sector field inductively coupled plasma mass spectrometer (HPLC-SF-ICPMS) is reported. Size exclusion chromatographycoupled to SF-ICPMS was used to measure the iron-containing biomolecules in the samples. This approachallowed for the direct on-line detection of the mostabundant iron isotope ⁵⁶Fe without interference from⁴⁰Ar¹⁶O. The HPLC-ICPMS results for the iron speciationanalysis of a raw beef steak, used as an analytical qualitycontrol (AQC) sample, showed that the main iron biomolecule present was the heme iron-containing protein myoglobin. For the AQC sample, the agreement among theHPLC-ICPMS method, the non-heme iron spectrophotometric method, and the total iron concentration showed100% recovery of iron. The sum of the different iron-containing compounds determined using the developedHPLC-ICPMS method accounted for all the iron-containing compounds extracted. The analysis of myoglobin insteak by HPLC-ICPMS showed that on cooking theconcentration was reduced by 85%. However, a spectrophotometric method specific for heme iron showed thatit was still intact, even after heating to 80 C. Themeasurement of the total iron in the cooked steak andthe HPLC extracts by inductively coupled plasma opticalemission spectroscopy (ICP-OES) indicated that theextraction method for the HPLC analysis was no longerapplicable and that loss of the heme group from theprotein rendered it incompatible with the size exclusionseparation. The detection limit (concentration equivalentto 3 times the baseline for a blank injection) of the HPLC-ICPMS method was 2.4 ng as iron. The results demonstrate that a combination of analytical methods can beused to provide valuable information about dietary levelsof nutritionally important metal-containing compounds aswell as the efficiency of established extraction methodsfor raw and cooked meat samples.