Comparison of liquid–liquid extraction and solid-phase extraction for the determination of polycyclic aromatic hydrocarbons in the milk of Taiwan

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment and humans may be exposed to them through inhalation and ingestion. Most environmental hormones are carcinogens and can cause mutation. The study aims to quantify the content of PAHs in milk from various extraction solvents in different analysis methods. Random samples of milk produced in Taiwan and popular milk brands are the study objects and the collected milk is experimented in order to understand the main distribution and feature of PAHs all around Taiwan. Liquid–liquid extraction method is applied to check the content of PAHs. The result shows that four chemical compounds are found, i.e. NaP, AcP, Flu, and PA. Furthermore, toxic BaP is found in four samples of milk produced in Taiwan and two in popular milk brands. According to the factor analysis, the fall-point between the first and the second factor is very close and it means that the pollutant of PAHs could be from the same area or a close area. It shows that due to the dense population, the milk production center is possibly located in a busy traffic area and the exhaust emitted from vehicles could be the possible source.