Development of Reference Materials for Nitrogen Content of Petroleum Products

The chemiluminescence nitrogen meter needs to be calibrated with the standard material of nitrogen content in petroleum to realize the traceability of the quantity value. In the present study, the development of six Certified Reference Materials (CRMs) for petroleum with nitrogen content ranging from low to middle were described. This series of CRMs were prepared and certified by the internationally recognized gravimetric method, and the certified value, nitrogen content, was traceable to SI unit of mass and volume, as well as to the pure organic substance CRM for elemental content. The homogeneity and stability of CRMs were technically qualified. The certified nitrogen concentrations of this series of CRMs were 2.04 mg/L, 5.03 mg/L, 9.91 mg/L, 19.6 mg/L, 50.3 mg/L, and 100.7 mg/L, with corresponding uncertainty U (k=2) of 0.08 mg/L, 0.10 mg/L, 0.16 mg/L, 0.5 mg/L, 0.9 mg/L, and 1.2 mg/L, respectively. The development process of this series of reference materials conforms to relative standards, and the uncertainty has reached the same level as that of similar reference materials in China. It is suitable for the verification and calibration of chemiluminescence nitrogen meters and is conducive to ensuring the accuracy and reliability of the nitrogen content of petroleum products.