Investigation of Matrix Effects on the Determination of Carbadox and Olaquindox in Feed by LC–MS/MS

A comprehensive survey of matrix effects on the LC–MS/MS analysis of the banned antibiotic growth promoters carbadox and olaquindox in feed was carried out. Various factors of sample preparation procedure and measurement were systematically investigated by pre- and post-extraction addition and postcolumn infusion experiments. In general, strong signal suppression up to 70 % for carbadox and up to 90 % for olaquindox was observed when using different extraction solvents and techniques as well as different chromatographic conditions. Reduction of matrix effects was achieved by SPE clean-up and dilution of sample extracts. Nevertheless, matrix effect profiles determined by postcolumn infusion revealed, that reduction of signal suppression at a respective retention time cannot guarantee improvement of the methods performance. If high variability of matrix effects is present along the chromatographic run, accuracy might decrease despite reduced signal suppression. Besides method parameters, different feedingstuffs were investigated and showed similar matrix effects.

     

Investigation of Matrix Effects on the Determination of Carbadox and Olaquindox in Feed by LC–MS/MS

A comprehensive survey of matrix effects on the LC–MS/MS analysis of the banned antibiotic growth promoters carbadox and olaquindox in feed was carried out. Various factors of sample preparation procedure and measurement were systematically investigated by pre- and post-extraction addition and postcolumn infusion experiments. In general, strong signal suppression up to 70 % for carbadox and up to 90 % for olaquindox was observed when using different extraction solvents and techniques as well as different chromatographic conditions. Reduction of matrix effects was achieved by SPE clean-up and dilution of sample extracts. Nevertheless, matrix effect profiles determined by postcolumn infusion revealed, that reduction of signal suppression at a respective retention time cannot guarantee improvement of the methods performance. If high variability of matrix effects is present along the chromatographic run, accuracy might decrease despite reduced signal suppression. Besides method parameters, different feedingstuffs were investigated and showed similar matrix effects.