The present invention provides a novel ferrocene compound; a reagent containing the compound; a high-sensitivity method of measuring a vitamin D compound using the reagent; etc. Specifically, a ferrocene compound represented by the following formula (1):
 is reacted with a vitamin D compound and the combined compound of these compounds is subjected to LC/ESI-MS/MS. Thus, the VD compound can be measured with higher sensitivity than in conventional techniques. The ferrocene compound of the present invention is extremely useful as a derivatization agent when a VD compound is measured by LC/ESI-MS/MS. The obtained compound wherein the ferrocene compound and the VD compound have been combined with each other, is useful as, e.g., a labeled compound, when the VD compound is measured by LC/ESI-MS/MS.
                            本发明提供了一种新型
二茂铁化合物;一种含有该化合物的试剂;一种使用该试剂测量
维生素 D 化合物的高灵敏度方法等。具体地说,由下式(1)代表的
二茂铁化合物:
 与
维生素 D 化合物反应,然后将这些化合物的组合物进行 LC/ESI-MS/MS 分析。因此,与传统技术相比,
二茂铁化合物的测量灵敏度更高。当通过 LC/ESI-MS/MS 测量 VD 化合物时,本发明的
二茂铁化合物作为衍生剂非常有用。
二茂铁化合物和 VD 化合物相互结合后得到的化合物,在用 LC/ESI-MS/MS 测量 VD 化合物时,可用作标记化合物等。