Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion and pyrolysis processes. They are released into the environment through flue gases bound to dust particles or mineral oil residues. They enter food either through environmental input or through roasting and smoking processes.
PAHs are regularly tested in laboratories. The reason for this is the partly very high carcinogenicity of this group of substances and their wide distribution. The European regulations prescribe limit values which vary depending on the foodstuff from 1-6 µg/kg for the marker substance benzo[a]pyrene and cumulative limit values of 1-35 µg/kg for PAH4 (this term covers benzo[a]pyrene, benzo[a]anthracene, chrysene and benzo[b]fluoranthene).
Nevertheless, the determination of PAHs with the necessary sensitivity in the multitude of possible food matrices is a great challenge for analytics. Sample preparation is often very extensive and time-consuming. The analytical methods used are either HPLC with fluorescence detection or GC-MS. In the course of the demands on today's laboratories to reduce sample processing times (turn-around time) and to increase sample throughput without compromising analytical parameters such as sensitivity, precision and accuracy, highly automated analytical methods are required for analysis.
The CHRONECT Workstation PAH is based on the LC-GC technology, which has been established in the routine analysis of food for several years. Together with the imPAHct method (innovative multidimensional PAH clean-up technology) it forms the ideal basis for such an application system. The analysis is performed with an LC-LC-GC-MS/MS system and the imPAHct method. To determine PAH, a simple and fast extraction of the sample is performed. After a short manual processing with the CHRONECT Workstation PAH the extract is purified by a two-step LC-separation (LC-LC-Clean-Up) and then analyzed by GC-MS. Edible oils can be measured directly.
This intelligent matrix management makes it possible to determine the PAHs prescribed by the EFSA for analysis fully automatically. Depending on the detector, detection limits are even achieved that are lower by a factor of 100 than the prescribed European limits for baby food.
Advantages of the CHRONECT Workstation PAH and the imPAHct method
- LOD 1/100 of the limit value for baby food (example substance benzo[a]pyrene)
- LOD for all EFSA PAH between 0.01 -0.02 μg/kg with Bruker EVOQ GC-TQ
- LOQ for all EFSA PAH < 0.06 μg/kg with Bruker EVOQ GC-TQ
- Repeatability < 10 % for total method
- Analysis duration: 45 min
- No consumables due to LC-LC-Clean-Up
- Longer maintenance intervals due to Clean-Up technology
- High sample throughput
- Expandable to further applications
Marco Nestola was awarded the Ernst Bayer Preis 2016 for his publication on this separation technology.