BACKGROUND Polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have teratogenic, carcinogenic and mutagenic effects, which are priority pollutants. The formulation of pollution investigation and treatment measures depends on accurate analysis and test data, and certified reference materials (CRMs) are an important guarantee for data quality control. However, the existing relevant reference materials cannot meet the actual needs of pollution monitoring in China.

OBJECTIVES To prepare four CRMs of sediments for analysis of PAHs, OCPs and PCBs, and to meet the needs of environmental monitoring and scientific research for the monitoring of priority pollutants in China.

METHODS In this study, according to the specifications of certified reference materials (JJF 1006—1994, JJF1343—2012 and JJF 1646—2017), 4 CRMs of PAHs, OCPs and PCBs in different sediments (GBW07352-GBW07355) have been developed for Chinese environmental monitoring and scientific research. In the development process, in order to solve the technical difficulties of the stability of organic compound reference materials, the effects of ⁶⁰Co sterilization and temperature on the stability of organic compounds were investigated. In view of the complex characteristics of the sediment sample matrix, different extraction and purification technologies were adopted to reduce or eliminate the influence of the complex matrix on the extraction solution and reduce the matrix effect of instrument measurement. Nine laboratories' collaborative analysis was carried out by using traditional methods including high performance liquid chromatography (HPLC), gas chromatography-electron capture detector (GC-ECD), gas chromatography-mass spectrometry (GC-MS) and new techniques of gas chromatography-isotope dilution mass spectrometry (GC-IDMS).

RESULTS The sediment candidates have good homogeneity and stability. The certified values and expanded uncertainty for 16 PAHs, 3 OCPs and 3 PCBs are given, and the concentrations range from 9.0ng/g to 5.7μg/g, which meets the requirements of quality assurance and quality control for analysis of PAHs, OCPs and PCBs.

CONCLUSIONS This series of reference materials has been approved as a national first-class reference material, numbered from GBW07352 to GBW07355. This series of CRMs can be used in analytical method validation, laboratory quality control, laboratory analysis ability assessment.