Evaluation of two liquid chromatography/tandem mass spectrometry platforms for quantification of monensin in animal feed and milk

Abstract

Monensin is an anticoccidial drug that has been used as an additive in medicated feed. The United States Food and Drug Administration (USFDA) has included monensin in the national surveillance schemes for residues in foodstuff. In this study, two simple, selective and rapid methods were developed to determine monensin content in animal feed and milk. The methods enabled the detection of monensin residues as low as 1 ppb. Moreover, the two methods were used as models to compare two common liquid chromatography/tandem mass spectrometry (LC/MS/MS) platforms; an LC linear ion trap (LC/LIT) and an LC triple quadrupole (LC/QqQ). The two instrument platforms were evaluated for their matrix effect dependence, precision and accuracy. The LC/QqQ presented a lower limit of detection and limit of quantitation (LOD and LOQ) and showed less matrix dependence as compared to the LC/LIT. The LC/QqQ instrument also demonstrated a better intermediate precision. For example, the intermediate precision standard deviation calculated for 27 analyses across three days was 4% and 11% for LC/QqQ and LC/LIT, respectively. Overall, the LC/QqQ represents a better choice for analysis of monensin with respect to LOD, LOQ, matrix interference and precision.

Feed additives and veterinary drugs as contaminants in animal feed – the problem of cross-contamination during feed production

“…The limit of detection (LOD) for the method was 0.3 mg kg −1 , while the LOQ was 1 mg kg −1 . Dai and Herrman (2010) have presented two individual LC-MS/MS platforms for quantifi cation of monensin in animal feed and milk. The platforms investigated were an LC linear ion trap (LC-LIT) and an LC triple quadrupole (LC-QqQ).…”

Metabolite identification and quantitation in LC-MS/MS-based metabolomics

“…A recent comparison study between LC-LIT-MS and LC-QqQ-MS showed that QqQ-based LC-SRM-MS/MS is still a better choice for small-molecule analysis with respect to limit of detection, lower limit of quantitation and precision [45]. …”

The Determination of Six Ionophore Coccidiostats in Feed by Liquid Chromatography with Postcolumn Derivatisation and Spectrofotometric/Fluorescence Detection

“…Although MS-based methods can be both used for the reliable determination of single representative of ionophore family [7, 8] and to screen all authorized polyether antibiotics [9], this approach is not always available to routine laboratories because of high cost of purchase and maintenance of mass spectrometer. Also relatively high variation of results is observed due to lack of labelled internal standards.…”