Fruit and vegetable extracts that are produced following the well established QuEChERS method [1,2] typically contain a significant amount of involatile matrix material. After several injections of such extracts into the GC, sufficient matrix residue will be present in the GC inlet liner to lower or sometimes even increase the response of certain pesticide compounds affecting the accuracy of the analysis. The performance can be restored by exchanging the GC inlet liner. Normally this has to be done manually which means stopping the analysis sequence. The GERSTEL Automated Liner Exchange system (ALEX) provides an automated solution. As this study shows, automated liner exchange restores the original performance of the GC system and is therefore generally useful for the analysis of extracts that contain involatile matrix residue.

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Automated Liner EXchange (ALEX)

Improved routine analysis of samples with high levels of involatile compounds, particulates and other solid matrix material

Matrix residue from samples can contaminate a GC inlet liner afterwithin a few runs, leading to peak broadening and loss of analytes through adsorption in the liner. Under such conditions, the analyst is forced to perform frequent liner replacement, an operation which normally requires manual intervention. Running large series of samples will represent a serious challenge.

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