Analytical methods have to be fast and easy and to be able to recover a large number of analytes. The analysis of pesticide residues in spices, herbals, tea or hops is considered difficult due to the complexity of the matrix.
With the “Q19” method using combined mini SPE (PSA, NH2, MgSO4 from Agilent and
UCT) we developed a processing approach, which is more suitable for complicated matrices than the current § 64 methods of the LFBG, QuEChERS and DFG S19[2,3] and which is not as time and solvent consuming as modified QuEChERS . But there is only a limited variety of commercially available SPE- cartridges.
To expand the spectrum of analytes we wanted to optimize the SPE sample preparation by varying the composition of the SPE cartridges. For this purpose we tested and combined different commercially available materials und we checked if and which analytes got lost during the sample preparation.
As a result we were able to develop a SPE combining different materials, which covers a wide range of analytes with good purification results of difficult matrices.
Sample preparation for multiple-residue analysis with an optimized SPE
 A. Romanotto, J. Langner, K. Speer. Q19 in der Routine: Automatisierte Probenaufarbeitung für das schnelle Pestizidscreening in schwierigen pflanzlichen Matrices, LABO
 Official collection §64 LFBG: determination of pesticide residues in fruit and vegetables using GC-MS and/or LC-MS/MS after acetonitrile-extraction/distribution and cleaning with dispersive SPE (QuEChERS) (acc. to DIN EN 15662); L 00.00-115; 2014-02
 Official collection §35 LFBG: modular multi-method to determine plant protection substances residues in food (extended new version of DFG method S19), L 00.00-34
 Multi-residue Pesticide Analysis in Green Tea by a Modified QuEChERS Extraction and Ion Trap GC/MSn Analysis
 J. Langner, A. Romanotto, Optimized Sample Preparation for Multi-residue PesticideAnalysis in Difficult Matrices, poster presentation; EPRW 2018