Pancosma SA, voie des Traz 6, 1218 Le Grand Saconnex, Switzerland.
Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Research Unit: Analytical BioGeoChemistry, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
J Trace Elem Med Biol. 2019 Dec;56:207-212. doi: 10.1016/j.jtemb.2019.08.010. Epub 2019 Aug 24.
Traceability of metal-glycinate-sulphate complexes (Metal-GLY) in feed requires specific analysis to differentiate complexes from inorganic forms. A previously described method focused on the quantification of Metal-GLY at one single concentration but not on the quantification of free metal ion forms. The objective of this work was to extend the method to quantify both Metal-GLY and free metal ion forms of various metals at low inclusion levels. A 50/50 w/w mix of corn flour and soybean meal was used as feed. Copper-glycinate(Cu-GLY), Manganese-glycinate (Mn-GLY) and Zinc-glycinate (Zn-GLY) complexes (provided by Pancosma SA) were used for in-feed inclusions. The feed metal background concentrations and species repartitions were assessed. Cu-GLY was spiked on feed at levels matching 5, 15 and 45 mg/kg, corresponding to metal concentrations of 1.2, 3.6 and 10.8 mg/kg. Mn-GLY and Zn-GLY were spiked at 15, 45 and 100 mg/kg, corresponding to 3.3, 9.9, 22 mg/kg Mn and 3.9, 11.7, 26mg/kg Zn, respectively. The water soluble fraction of un-supplemented feed contained 0.06 mg/kg Cu, 0.05 mg/kg Mn and 0.12 mg/kg Zn, with 69.5% of Cu, 33.2% of Mn and 24.3% of Zn being present under free metal ions but 30.4% of Cu being present under Cu-GLY, 66.82% of Mn and 75.7% of Zn being present under Mn-GLY and Zn-GLY, respectively. The supplemented feeds at the 3 tested doses, from the lowest to the highest inclusion levels, contained in total respectively: 1.1, 3.05 and 9.06 mg/kg Cu; 2.99, 8.9 and 18.2 mg/kg Mn; 3.72, 10.9 and 23.4 mg/kg Zn. The M-GLY species recovered by analysis within the different supplemented feeds ranged from 76.26 to 89.32% for Cu-GLY, form 94.5 to 98.51% for Mn-GLY and from 76.05 to 98.96% for Zn-GLY. These results showed that CE-ICP-MS technique can be used to quantify low doses and to measure metal-species repartition between Metal-GLY and free metal ions, when included in feeds. For the first time, this study highlighted that the raw materials used contain Metal-GLY compounds. This raises the question of the occurrence of these compounds within the different raw materials used in feed production that could dramatically affect the way to supplement minerals in animal feed.
金属甘氨酸硫酸盐复合物（Metal-GLY）在饲料中的溯源需要特定的分析方法来区分复合物与无机形式。先前描述的方法侧重于单一浓度下 Metal-GLY 的定量，但不能定量游离金属离子形式。本工作的目的是扩展该方法，以定量各种金属的低含量 Metal-GLY 和游离金属离子形式。玉米粉和豆粕的 50/50w/w 混合物用作饲料。铜甘氨酸（Cu-GLY）、锰甘氨酸（Mn-GLY）和锌甘氨酸（Zn-GLY）复合物（由 Pancosma SA 提供）用于饲料添加。评估了饲料中金属背景浓度和物种分布。在饲料中添加 Cu-GLY 的水平分别为 5、15 和 45mg/kg，对应金属浓度为 1.2、3.6 和 10.8mg/kg。Mn-GLY 和 Zn-GLY 添加水平为 15、45 和 100mg/kg，分别对应 3.3、9.9 和 22mg/kg Mn 和 3.9、11.7 和 26mg/kg Zn。未添加补充剂的饲料的水溶性部分含有 0.06mg/kg Cu、0.05mg/kg Mn 和 0.12mg/kg Zn，其中 69.5%的 Cu、33.2%的 Mn 和 24.3%的 Zn 以游离金属离子形式存在，但 30.4%的 Cu 以 Cu-GLY 形式存在，66.82%的 Mn 和 75.7%的 Zn 以 Mn-GLY 和 Zn-GLY 形式存在。在 3 个测试剂量下，从最低到最高的添加水平，总含量分别为：1.1、3.05 和 9.06mg/kg Cu；2.99、8.9 和 18.2mg/kg Mn；3.72、10.9 和 23.4mg/kg Zn。在不同添加饲料中通过分析回收的 M-GLY 种类分别为 Cu-GLY 的 76.26%至 89.32%，Mn-GLY 的 94.5%至 98.51%和 Zn-GLY 的 76.05%至 98.96%。这些结果表明，CE-ICP-MS 技术可用于定量低剂量，并测量 Metal-GLY 与游离金属离子之间的金属物种分布，当它们包含在饲料中时。本研究首次表明，所用原料含有 Metal-GLY 化合物。这就提出了在饲料生产中使用的不同原料中存在这些化合物的问题，这可能会极大地影响在动物饲料中补充矿物质的方式。
