Analytical chemistry benefits from uniformly applied and readily accessible reference materials to assess the accuracy of experimental results. Without assessment, experimental findings are best considered with a healthy dose of skepticism. For several chemical analyses, reference materials are available commercially Amino acids, for example, are biochemical analytes for which standard materials are readily available from commercial vendors. There are many environmental analyses, however, for which reference materials are not available. One such measurement had been that of organic carbon dissolved in natural waters.