Abstract

A sensitive method for determining lincomycin in bovine milk, animal muscles and organs using liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) is presented. Milk and homogenized animal tissues were extracted with acetonitrile twice after addition of an appropriate amount of clindamycin, a lincosamide analogue as the internal standard. The combined extracts were finally made up to 10 ml with distilled water and partitioned with hexane to remove the animal fats prior to analysis. Analytes in the extracts were separated on a reversed phase C18 column ( 250 mm×2.1 mm, 5 μm) using a mobile phase of a 3:7 (v/v) mixture of 0.1% formic acid in acetonitrile and an ammonium formate buffer (ammonium formate:formic acid:acetonitrile:water, 1:5:50:950, v/v/v/v) running at a flow rate of 0.2 ml min −1. Presence of lincomycin was confirmed by the presence of two characteristic product ions at m/ z 126.1 and 359.2 within a defined retention time window from the precursor ion at m/ z 407.2, whilst quantification was based on the relative ratio of the sum of the peak areas at m/ z 126.1 and 359.2 for lincomycin to that of the internal standard (peaks at m/ z 126.1 and 377.2) with reference to the respective ratios of the calibration standards. The validated method that was found to have linear responses in the calibration range from 25 to 3000 μg kg −1 and satisfactory intra-day and inter-day accuracy (94.4–107.8%) and precision (1.3–7.8%) at concentrations ranging from 100 to 1500 μg kg −1 has been applied to real samples and matrix spiked samples. It is considered robust and suitable for analysis of lincomycin in milk and animal tissues.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.