The streptomycin in 500 g of a broth was determined by addition of 1.34 mg of the pure antibiotic containing 14C. The specific activity of this preparation was found to be 223 cpm/mg for a 30-min count. From the mixture, 0.112 mg of purified streptomycin was isolated, which produced 654 counts in 60.0 min. Calculate the concentration in parts per million streptomycin in the sample.