The invention relates to a method for removing foreign particles from a sample of biological origin to be examined. Fields of application are the food industry, the animal feedstuff industry or biotechnology. The method according to the invention for preparing the analytics of samples of biological origin comprises receiving the biological sample in a buffer system with a pH of 7-10, followed by precipitation of foreign substances with multivalent metal ions of the lanthanide group, separation of the precipitate, separation of excess multivalent metal ions by precipitation, and analysis of the supernatant.