Development of a simple and efficient method for monitoring polycyclic aromatic hydrocarbons in liquid smoke

Liquid smoke is a food additive produced from wood pyrolysis under controlled conditions. However, this process can lead to forming polycyclic aromatic hydrocarbons (PAHs), which are classified as possible carcinogens for humans. In this work, a simple method based on liquid-liquid extraction with low-temperature purification (LLE-LTP) followed by gas chromatography-mass spectrometry (GC-MS) analysis was optimized and validated to quantify benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a) pyrene, indeno[1,2,3-Cd]pyrene and dibenzo(a,h)anthracene in liquid smoke samples. The results showed PAH recovery between 95 and 114 % and relative standard deviation below 10 %. The detection and quantification limits for the target analytes were 2 mu g L-1 and 5 mu g L-1, respectively. The analytical curves prepared in the matrix extract showed a coefficient of determination (R2) greater than 0.99, with the exception of indeno[1,2,3Cd]pyrene (0.97). The proposed method was applied to monitor the seven PAHs in 10 commercial liquid smoke samples. Three samples were contaminated by PAHs with concentrations ranging from 8 to 45 mu g L-1. The developed method proved to be an efficient, low-cost and easy-to-perform alternative to quantify PAHs in liquid smoke.