![Analysis of major components of residual bacitracin and colistin in food samples by liquid chromatography tandem mass spectrometry [An article from: Analytica Chimica Acta]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR3IIW.jpg)
Analysis of major components of residual bacitracin and colistin in food samples by liquid chromatography tandem mass spectrometry [An article from: Analytica Chimica Acta]
Description
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
A selective and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method has been developed for simultaneous determination of residual bacitracin and colistin in bovine milk samples. Milk samples were deproteinized and extracted with a mixture of trichloroacetic/formic acid. After centrifugation, bacitracin and colistin in the extracts were separated on a reversed phase Alltima BDS C"1"8 column (250mmx2.1mm, 5@mm) using a gradient elution programme of ammonium formate buffer (saturated ammonium formate:formic acid:acetonitrile:water, 1:5:50:950, v/v/v/v) and 0.1% formic acid in acetonitrile at 0.2mlmin^-^1. Using electrospray LC-MS/MS with time-scheduled multiple reaction monitoring (MRM), identification and quantification of the major components of the two polypeptides were performed based upon the intensities of mass fragments from the respective doubly charged precursor ions: bacitracin A at 712->199amu and 712->227amu, and colistin A at 586->101amu, 586->202amu and 586->241amu, respectively, at the defined retention time windows and the matching of the specific tolerance of the relative abundance of the monitored ions. Polymyxin B, a polypeptide of colistin family, was employed as the internal standard. With an additional solid phase extraction procedure, the analytical method was applicable to the analysis of the two polypeptide antibiotics in animal's liver and tissue samples. The practical quantification limits of bacitracin A and colistin A were 100 and 50@mgkg^-^1; and mean intra-day (n=7) and inter-day (n=4) recoveries were in the range of 89.2-110% (R.S.D.
Description:
A selective and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method has been developed for simultaneous determination of residual bacitracin and colistin in bovine milk samples. Milk samples were deproteinized and extracted with a mixture of trichloroacetic/formic acid. After centrifugation, bacitracin and colistin in the extracts were separated on a reversed phase Alltima BDS C"1"8 column (250mmx2.1mm, 5@mm) using a gradient elution programme of ammonium formate buffer (saturated ammonium formate:formic acid:acetonitrile:water, 1:5:50:950, v/v/v/v) and 0.1% formic acid in acetonitrile at 0.2mlmin^-^1. Using electrospray LC-MS/MS with time-scheduled multiple reaction monitoring (MRM), identification and quantification of the major components of the two polypeptides were performed based upon the intensities of mass fragments from the respective doubly charged precursor ions: bacitracin A at 712->199amu and 712->227amu, and colistin A at 586->101amu, 586->202amu and 586->241amu, respectively, at the defined retention time windows and the matching of the specific tolerance of the relative abundance of the monitored ions. Polymyxin B, a polypeptide of colistin family, was employed as the internal standard. With an additional solid phase extraction procedure, the analytical method was applicable to the analysis of the two polypeptide antibiotics in animal's liver and tissue samples. The practical quantification limits of bacitracin A and colistin A were 100 and 50@mgkg^-^1; and mean intra-day (n=7) and inter-day (n=4) recoveries were in the range of 89.2-110% (R.S.D.
