the invention discloses a separating method of plastid DNA through silica-magnetic nanometer compound, which comprises the following steps: preparing superparamagnetism ferric oxide nanometer particle based on Fe2+ and Fe3+ salt and ammonium hydroxide under nitrogen environment through chemical sedimenting method; hydrolyzing tetraethoxysilane through acid to produce silica on the magnetic ferric oxide nanometer particle to prepare silica-magnetic nanometer compound carrier; adsorbing sample with plastid DNA and silica-magnetic nanometer compound carrier on the carrier under high-salt condition; recycling the silica-magnetic nanometer compound carrier through permanent magnet; recycling the plastid DNA through remained clarified solution. |