HPLC determination of lincomycin in premixes and feedstuffs with solid-phase extraction on HLB OASIS and LC-MS/MS confirmation.

A rapid clean-up procedure based on solid-phase extraction (SPE) and HPLC determination of lincomycin in premixes with UV detection is described. After extraction of lincomycin from premix with extraction solvent the extract is applied to OASIS HLB column treated with methanol and water. Lincomycin is eluted with methanol and effluent is analysed on analytical column (phenyl) using mobile phase consists 0.2% phosphoric acid in water and acetonitrile (875:125, v/v). Detection is performed at 208 nm. Quantitation is carried out using external standard. The mean recovery of lincomycin was 105.0+/-7.3%, in concentration range of 250-750 mg kg(-1), and 99.8+/-3.7%, in concentration range of 10,000-150,000 mg kg(-1). The limit of determination, based on a signal-to-noise ratio of 10:1, was 5.2 mg kg(-1). LC-MS/MS confirmation of lincomycin is also presented. Identification was performed by monitoring two pairs of multiple reaction monitoring ions from the parent ions (m/z 407.2-->126.1 and 407.2-->359.2) at the defined retention time window and by matching of the specific tolerance of relative abundance of major ions as stated in the European Union Commission Decision 2002/657/EC.