AS154: Automatic Liner Exchange (ALEX) to Deal with Dirty Matrices Using GC/Q-TOF

Martin Perkins

18th January 2018

The use of non-selective extraction protocols, such as QuEChERS (Quick Easy Cheap Effective Rugged and Safe) can result in dirty sample extracts, which can mean deterioration of chromatographic performance and the need to replace inlet liners frequently.

The use of the GERSTEL Automated Liner EXchange (ALEX) was demonstrated for the analysis of Pesticides in Coriander extracts. This matrix was chosen as representative of a ‘dirty’ plant matrix containing a number of non-volatile components. The liner was changed every 5 injections and linearity and precision experiments were performed.

No chromatographic deterioration was observed and RSDs of <10% were achieved (without IS) for a sample spiked at 50 ng/L. This work was performed on the Agilent GC/Q-TOF and also demonstrated the increased selectivity (and hence sensitivity) achievable using accurate mass for target compounds – due to the ability to extract a more selective mass range and thus reduce noise from any remaining matrix interferences.

The use of ALEX also reduces the need for instrument maintenance, thus reducing down time and increasing sample throughput.