Validation (in-house and collaborative) of a method based on liquid chromatography for the quantitation of 15 European-priority polycyclic aromatic hydrocarbons in smoke flavourings: HPLC-method validation for 15 EU priority PAH in smoke condensates

A method based on high-performance liquid-chromatography with ultra-violet absorption and fluorescence detection was developed for the purpose of quantitation of 15 carcinogenic and mutagenic polycyclic aromatic hydrocarbons named by European legislation (EU priority PAHs) in the aqueous phase of primary smoke condensates (PSCs). These PSCs form the raw materials for the production of smoke flavourings to be used in or on food. The method complements a method based on gas-chromatography with mass-selective detection (GC–MS) enabling laboratories without GC–MS to perform the legally required analyses. The method was first validated in-house according to the IUPAC harmonised guideline for single-laboratory validation. Here the limit of detection values of the analytes lay between 0.1 and 1.2 μg/kg, the limit of quantification values between 0.5 and 4.0 μg/kg, and the values of the recoveries between 41% and 107%. The method thus could be used to monitor all 15 EU priority PAHs in PSC. Subsequently a collaborative trial was organised according to the IUPAC protocol for the design, conduct and interpretation of method-performance studies involving 11 laboratories of nine countries. The average values lay between 23% and 99% for the relative standard deviation of the reproducibility and between 24% and 76% for the recovery, which is showing the limits of this method in a worst case scenario.