OPTIMIZATION OF LARGE VOLUME INJECTION FOR IMPROVED DETECTION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) IN MUSSELS

Abstract

Detection of PAH of six benzene rings is somewhat troublesome and lowering the limits of detection (LODs) for these compounds in food is necessary. For this purpose, we optimized a Programmable-Temperature-Vaporisation (PTV) injection with Large Volume Injection (LVI) with regard to the GC-MS detection of anthracene, benz[a]anthracene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene and dibenzo[a,e]pyrene. The optimization of PTV-LVI for GC-MS analysis included the choice of liner, solvent venting, splitless time, split flow and initial inlet temperature for injection of 25 μ L standard solution and spiked mussel samples. Samples were extracted with Accelerated Solvent Extraction (ASE) followed by two semi-automatic clean-up steps; gel permeation chromatography (GPC) on S-X3 and solid phase extraction (SPE) on pre-packed silica columns, prior to gas chromatography-mass spectrometry (GC-MS) detection. In comparison to traditional splitless injection, LODs were lowered for eighteen PAHs by the use of PTV-LVI ranging from 0.05 μ g kg ⁻¹ to 1.0 μ g kg⁻¹ fresh weight. In particular, the LOD of dibenzo[a,e]pyrene was improved by a factor of ten when using the validated PTV-LVI method.

Keywords:

• accelerated solvent extraction (ASE)
• gel permeation chromatography (GPC)
• validation
• benzo[a]pyrene
• dibenzopyrenes

The authors would like to thank Vibeke Balswel, National Food Institute for technical assistance on the analysis, Bjarne R. Thorbj⊘rnson, National Veterinary and Food Administration, for coordination and questions on sampling of real-life samples and Lawrence White for valuable discussions on language and manuscript structure.

Notes

^aLimit of quantification, LOQ = 2∗ LOD.