Assessment of the fitness for purpose utilisation of 5-hydroxymethyl-2-fufural quantification analysis in FAPAS proficiency tests

Abstract

The international utilisation of 5-hydroxymethyl-2-fufural (HMF) as an indicator of honey quality necessitates its appropriate laboratory analysis. FAPAS supplies associated proficiency tests to externally assess the analytical performance. Currently, HMF results submitted are separated and analysed according to whether HPLC or spectrophotometric methods were used. This study aimed to establish whether data from the two methods could be analysed in combination for PTs at HMF concentrations of honey quality concern and remain fit for purpose. 15 years' worth of FAPAS honey proficiency test data was analysed. 25 PTs' result distributions, assigned values and RSD_Rs were compared. Alterations to z-score outcomes when HPLC and spectrophotometric results are combined and the Horwitz function used alternatively to Apidologie collaborative trial data were considered. The majority of PTs showed submitted spectrophotometric results did not significantly differ to those using HPLC. Assigned values generated by spectrophotometric and HPLC results displayed were correlated (linear functional relationship estimate, y = 0.16715 + 1.052x). 5.22% of z-scores revised to a ‘questionable’ value as a result of combining both method datasets, with spectrophotometric results being the most affected. HorRat values illustrated RSD_R values calculated using Horwitz instead of collaborative trial data are within acceptable parameters. Consequently, combining the two methods' results for assessment of HMF analysis proficiency tests at levels of interest to honey quality remains fit for purpose.