Reaction of boron carbide powders with biochemical media

The EPR signals have been detected in boron nitride powders (BNg and hexani te-A) from: car-bon atoms substituting for nitrogen atoms in the BNg lattic e, iron-containing formations; various carbon-containing inclusions. Treatm ent of these powders in different biochemical and control inorganic media w as generally accompanied by changes in the intensity of some signals (in th e BNg specimens) which reflect reactions with the media of real inclusions present in the commercial powders.