QuEChERS method and pre-mixes
Within a few years after its devleopment by Anastassiades et al. the QuEChERS method has gained a leading position for determination of pesticide residues in food by GC-MS or LC-MS allowing rapid and cheap clean-up of strong matrix-contaminated samples.
Standard clean-up of food samples
10 g sample are homogenised with 10 ml acetonitrile. After adding the internal standard the sample is shaken with 4 g MgSO4 and 1 g NaCI and afterwards centrifuged. 1 ml of the supernantant is spiked with 25 mg CHROMABOND® Diamino and 150 mg MgSO4 and shaken again. After centrifugation the supernatant is injected into the GC/MS.
For optimising the extraction of pH-dependent compounds, for minimising decomposition of sensitive substances and for broadending the matrix spectrum, different modifications of the QuEChERS method have been elaborated. Special silica phase for determination of pesticides in food samples with primary and secondary amine functions (PSA).
Particle size 45 µm, specific surface 500 m2/g, pH-stability from pH 2 to 8.