PURPOSE: To provide an optical analysis function such as sufficient shifting action even on a sample having unsaturated bonding, by forming an optical analysis reagent including fluorine by a lanthanide chelate compound of fluoro-β- diketone and a metal salt of fatty acid.

CONSTITUTION: A compound, wherein chiral carbon C is present as shown in a general formula, such as fluoro-β-diketone, is effective in forming a shifting reagent comprising lanthanide chelate such as europium chelate. Namely, owing to fluorine atoms, the shifting effect is excellent, overlap with the signal of a substrate is less, solubility for a solvent is increased, and the shifting reagent is stabilized by a cubic effect. A metal salt of fatty acid, which is expressed by a general formula (R"fCOO)nM is used together with a chelate. The metal salt effectively yields a relative action between an unsaturated compound such as olefin and the chelate through the metal element, and a composite compound is formed. This compound provides the shift of NMR spectrum.