SweEt validation of Cereal samples – LC-MS/MS analysis

SweEt validation of Cereal samples – LC-MS/MS analysis Anne Kruse Lykkeberg; Gitte Andersen & Mette Erecius Poulsen; Nordic Pesticide Workshop, 2013, Porvoo/Borgå

Agenda • Short summary of the Method • Non-linear standard curves • Validation

SweEtSampleClean up

LC-method • Analytical column: Genesis C18, 100x3 mm, 4 µm • Solvent A: 10/90 metanol/10 mM ammonium formate, pH 4 • Solvent B: Methanol

Pyrimethanil – linear regression

Pyrimethanil – quadratic regression

Pyrimethanil – cubic regression

Metribuzin – linear regression

Injection volumen - chromatograms Fenhexamid 5 µl 2 µl 0.001 mg/kg 1.00 mg/kg

Injection volumen - standard curvesEpoconazol 5 µl 2 µl

Initial validation – LC-compounds • 28 compounds out of 34 had acceptable recoveries

Spiroxamin • LogP = 2.89 • Low sensitivity LOD = 0.04 ng/ml • Only i SWEET – not QuEChERS • Recovery is good at the highest level

Compounds with lowrecoveries

Compound with highrecoveries

Conclusions • Samples in ethylacetate gives non linear standard curves for manypesticides • Using Quadraticfit and i few cases Cubicfit gives • Acceptable residuals with random distributions • Acceptable recoveries at threelevels • Compounds with Log P below 0 gives a poorrecoveryusing the SweEtmethod

Thankyou for your attention

SweEt validation of Cereal samples – LC-MS/MS analysis