CCQM-K146.1 subsequent comparison low-polarity analyte in high fat food: benzo[a]pyrene in olive oil

Abstract

Main textThe Track A key comparison on the determination of benzo[a]pyrene in olive oil (CCQM-K146) organized by the CCQM was finished in 2020. This key comparison was related to low polarity analytes in a high fat, low protein, low carbohydrate food matrix and was the model system selected to align with the OAWG strategy for comparisons to underpin the food sector. Due to requests from the participants of this comparison, CCQM organized a supplementary comparison CCQM-K146.1 for those NMIs or DIs who did not participate in CCQM-K146 or wished to improve their results from CCQM-K146.5 NMIs and DIs participated in CCQM-K146.1. Different extraction methods and SPE cartridges were applied in the sample pre-treatment. HPLC-FLD, GC-MS/MS and GC-TOF MS were applied for detection by the participants. Certified reference materials (CRMs) were adopted or pure materials assessed in house to guarantee traceability to SI for the calibrants.NIM's result for CCQM-K146 was equivalent with the CCQM-K146 KCRV, thus they demonstrated acceptable performance in determining the measurand and their result for CCQM-K146.1 was used as the KCRV. The KCRV and u(KCRV) values were 8.69 μg/kg and 0.18 μg/kg, respectively. The random effects model obtained in CCQM-K146 suggests a dark uncertainty term (tau) is present, and the tau of CCQM-K146 normalized to CCQM-K146.1 measurand level is included in the estimation of degrees of equivalence (DoE) for the participants in CCQM-K146.1. This helps establish a consistent expectation of performance amongst the two studies, even when comparing to a different anchor KCRV.One participant demonstrated their capabilities for this analysis, whereas the other three were all deviated from the KCRV. This supplementary comparison directly illustrates the capabilities in determining mass fraction of organic compounds, with molecular mass of 100 g/mol to 500 g/mol, having low polarity pKow < -2, in mass fraction range from 0.1 μg/kg to 1000 μg/kg in a high fat, low protein, low carbohydrate food matrix.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).