2-Quinoxalinecarboxylic acid-d4 (Standard) is the standard substance of 2-Quinoxalinecarboxylic acid-d4, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. 2-Quinoxalinecarboxylic acid-d4 is a deuterated compound of 2-Quinoxalinecarboxylic acid. 2-Quinoxalinecarboxylic acid has a CAS number of 879-65-2.