As its name suggests, the QuEChERS method (Quick, Easy, Cheap, Effective, Rugged, and Safe) has caused a breakthrough in pesticide residue analysis in the food sector. The QuEChERS method can be taken to a further level with the fully automated liquid handling platform "LISSY" from Zinsser Analytic. LISSY automates all the required steps for sample analysis – weighing in the sample, the precise and reproducible addition and mixing of solvents and reagents, and centrifugation if required. LISSY therefore provides a rapid and error free automated solution for the analysis of pesticide residues in samples using QuEChERS.
The vials are manually filled and then placed in a rack on the workbench.
Acetonitrile and the internal standard are added as system liquids with the pipetting
probes. The storage bottles are stored off the workbench in their original containers.
For through mixing the single tube vortexer TubeMix is used. It has a speed of 2,200 rpm.
The salt mixtures have either been manually prepared in tubes or automatically prepared
using REDI Super. The salt mixtures are carefully added to the samples using
For extraction with the salt mixture, the sample is vortexed thoroughly on the integrated TubeMix.
For the centrifugation step, the centrifuge is placed beneath the workbench and is
automatically loaded by the gripper arm. It carefully places the tubes into the centrifuge
racks. The centrifuge is automatically started by the WinLISSY software.
After the centrifugation step, an aliquot is taken and transferred to a purification tube
which is stored in a rack on the workbench.
The sample is then again placed into the centrifuge for a final centrifugation step.
Finally the sample is transferred to HPLC vials for GC/LC/MS. Altternatively the sample can be directly injected into the analysis system.