Quantitative Analysis of Clenbuterol in Pig Liver by LC-MS/MS/MS

We examined the utility of LC-MS/MS/MS in the rapid quantitative analysis of clenbuterol in pig liver. Compared with LC-MS/MS in the SRM mode, which gave a chromatogram of pig liver containing interference peaks near the target component peak, LC-MS/MS/MS generated a clear chromatogram with no interference peaks. Validation of the method yielded favorable results for both LC-MS/MS in the SRM mode and LC-MS/MS/MS, with trueness values of 95.5% and 102%, repeatability of 1.9% and 5.5%, and within-laboratory reproducibility of 2.0% and 5.1%, respectively. Moreover, the recovery of clenbuterol-d9 used as surrogate was ≥70% in both measurement methods and thus, validation was achieved in terms of both selectivity and limit of quantification. The results suggest that LC-MS/MS/MS has highly selectivity for quantitative analysis as the influence of interference peaks is suppressed, and can be used when quantification is difficult with LC-MS/MS in the SRM mode due to matrix effects.