Potassium tetranitroplatinate(II) is primarily used in analytical chemistry as a reagent for the detection and determination of various substances. It plays a significant role in the identification of potassium ions in solution, often forming characteristic precipitates that aid in qualitative analysis. Additionally, this compound is utilized in research and development for the synthesis of other platinum-containing compounds, which are valuable in catalysis and material science. Its stability and specific reactivity make it a useful component in specialized chemical processes and studies involving platinum chemistry.