Determination of semduramicin in poultry feed at authorized level by liquid chromatography single quadrupole mass...

A novel liquid chromatography single quadrupole mass spectrometry (LC-MS) method for the determination of the feed additive semduramicin, in poultry feed, was developed and single-laboratory validated. This work was selected as a real case scenario to outline the different steps that may be needed whenever the standardisation of an analytical method in the field of methods of analysis for animal feedingstuffs is attempted. In this manuscript the main achievements reached within the development and the single-laboratory validation of an analytical method for the determination of semduramicin in feedingstuffs are detailed. Semduramicin is extracted from the feedingstuffs with acetonitrile. The obtained extracts are then filtered and diluted appropriately. The separation has been carried out in a reverse phase C18 column using isocratic elution with a mixture of methanol and 20mM ammonium formate solution as mobile phase. The ammonium adducts have been selected for monitoring the coccidiostats signals in the mass spectrometry detector. The method has been successfully validated for the determination of semduramicin concentrations ranging between half of the minimum authorized concentration (10 mg kg(-1)) to twice of the maximum authorized concentration (50 mg kg(-1)). A good relative standard deviation for repeatability (RSD(r)) varying from 2.8 to 3.2% has been obtained whereas the relative standard deviation for intermediate precision (RSD(Int.)) ranged from 3.7 to 7.3%. The obtained analytical performance characteristics of the method demonstrated its fitness for the purpose, making thus the proposed method suitable to be submitted for the last phase within the standardisation procedure, i.e. the inter-laboratory study.