Process for the preparation of a metal complex in an oily organic matrix

Process for preparing a composition comprising a metal complex in an oily organic matrix, said process comprising the step of reacting a metal oxide, metal hydroxide, metal carbonate or a mixture thereof with a complexing agent in an oily organic matrix, wherein said metal oxide, hydroxide, or carbonate is an oxide, hydroxide, or carbonate of Li, Na, K, Mg, Ca, Al, Sn, Pb, Bi, As, Se, TI, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Cd, Pt, Au, or Hg, said complexing agent is salicylic acid, ascorbic acid, an amino acid, lactic acid, malic acid, tartaric acid, citric acid, mandelic acid, 2-hydroxy-4-methylthio butanoic acid (methionine hydroxy analogue), a monomer of lignin, a polymer of lignin, a C6-C15 aromatic acid, a C6-C15 heteroaromatic acid, nicotinic acid, nicotinamide, rosmarinic acid, sulfanilic acid, or a mixture thereof, and said oily organic matrix is vegetable oil, olein, C3-C36 fatty acid, mono-, di- or triglycerides of C3-C36 fatty acid, natural or synthetic wax, spermaceti, lanolin, paraffin wax, siccative oil or a mixture thereof.