National Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100193, PR China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Dec 15;877(32):4175-9. doi: 10.1016/j.jchromb.2009.11.007. Epub 2009 Nov 10.
A new and simple HPLC-MS method was developed for monitoring iodinated casein in feed premixes. In this method, feed premixes were hydrolyzed, and the iodotyrosines thus released were analyzed. Sample pretreatment included precipitation of transition metals ions with Na(2)S, hydrolysis with sodium hydroxide, and cleaning up with an Oasis SAX cartridge. Gradient elution was carried out on a C(18) column with water (containing 0.1% formic acid) and acetonitrile. Ion detection was performed using ESI positive SIM at m/z 262, 308, 388, and 434. Iodinated casein levels were monitored by qualitative analysis of the iodotyrosines released upon sample hydrolysis and by quantifying the 3,5-diiodotyrosine released. The validation data demonstrated that the method was selective and sensitive (<or=0.2mgg(-1)) for iodinated casein and had acceptable accuracy (recoveries: 81.3-106.7%) and precision (RSD: 1.7-16.0%).
建立了一种新的、简单的 HPLC-MS 方法用于监测饲料预混料中的碘化酪蛋白。在该方法中，将饲料预混料进行水解，然后分析释放的碘酪氨酸。样品预处理包括用 Na(2)S 沉淀过渡金属离子、用氢氧化钠水解和用 Oasis SAX 小柱净化。在 C(18)柱上进行梯度洗脱，流动相为水（含 0.1%甲酸）和乙腈。采用 ESI 正离子 SIM 在 m/z 262、308、388 和 434 处进行离子检测。通过定性分析样品水解释放的碘酪氨酸和定量分析释放的 3,5-二碘酪氨酸来监测碘化酪蛋白的水平。验证数据表明，该方法对碘化酪蛋白具有选择性和灵敏度（<或=0.2mgg(-1))，并且具有可接受的准确度（回收率：81.3-106.7%）和精密度（RSD：1.7-16.0%）。
