通过 μ-XRF 和 XANES 方法测定不同铁源进入肉鸡十二指肠肠壁中铁的价态和相对浓度

The objective of this study was to employ μ-XRF and XANES technique to determine the change of Fe quantity, distribution and valence in the duodenal wall using four different Fe sources. Procedure: Fifty newly hatched healthy (1-day-old) Arbor Acres commercial male broilers were used in this experiment. The chicks were fed a corn-soybean meal basal diet (96.00 mg of Fe/kg of diet) from d 1 to 21, but were fed a semipurified diet (12.50 mg of Fe/kg of diet) after d 21 to deplete the body Fe stores. At d 28 , after an overnight fast, all birds were randomly allotted to 4 different Fe sources (FeSO4, Fe-Gly (II), FeCl3 and Fe-Gly (III)) perfusion treatment groups and a perfusion group without Fe source added to the media was designed to exclude the effect of endogenous Fe by technology of in situ ligated intestinal loops in broilers. Four Fe sources of the experiment were added to the medium as treatment groups (40 mg of Fe/L). 3.5 mL of Fe dose was injected and incubated 30 min in the abdomen cavity. Each group was repeated 10 times using 10 birds (1 time with 1 bird). Duodenum of each bird was used as 1 replication of duodenal segments. μ-XRF and XANES were used to analyze the relative quantity, distribution and valence of Fe in the duodenal wall. Results: The results showed that Fe K-edge absorption values of two valent iron source (FeSO4, Fe-Gly (II)) and three valent iron source (FeCl3, Fe-Gly (III)) were significantly different. According to Fe μ-XRF maps of the duodenal wall, different Fe sources groups had more quantity Fe in the duodenal wall than perfusion groups without Fe source. The concentration of two valent Fe sources (FeSO4, Fe-Gly (II)) were significantly higher than that of three valent Fe sources (FeCl3, Fe-Gly (III)) in the duodenal wall. Fe-Gly (II) group sample had the biggest amount of Fe in the duodenal wall. The Fe XANES spectra of four Fe sources were basically the same in the duodenal wall. Conclusion: This paper demonstrates directly that the absorption pathways of organic Fe and inorganic Fe through the duodenal wall are the same.