This invention relates to a method of using MOF adsorbents to remove elemental impurities from feed streams comprising active pharmaceutical ingredients (API). The process involves contacting the feed stream comprising API and elemental impurities with the MOF at purification conditions to obtain a purified stream with provides an API which has a concentration of the elemental impurity below its permitted daily exposure. The process can be carried in a batch mode where the MOF and feed stream are admixed in a vessel for a given amount of time or continuously by flowing the feed stream through a column or adsorbent bed containing the MOF adsorbent.