MULTIRESIDUE METHOD FOR SIMULTANEOUS DETECTION OF THE RESIDUES OF SEDATIVES AND ß-BLOCKERS IN ANIMAL ORGANS AND TISSUES BY HPLC-MS/MS
Confirmatory method for quantification of residues of 17 sedatives and ß-blockers in animal tissues (muscles and by-products) was developed. Samples were homogenized, and analytes were extracted with acetonitrile. Extracts were concentrated and analyzed on HPLC-MS/MS system consisted of chromatograph with reversed-phase C18 column and mass spectrometer, working in MRM mode and equipped with electrospray ion source. Mass spectrometric conditions for analytical signals were optimized as well as parameters for chromatographic separation. Three types of chromatographic buffers were tested. All analytes were detected in positive mode. Two MRM transitions were used for quantification of each analyte. Internal standard method was used for quantitative analysis. Four approaches were tested during sample preparation optimization; two of those included solid phase extraction step. Matrix effects were investigated as well. The detection limits for these analytes are in the range of 1 - 10 |ig/kg. Method was validated according to RMG 61-2010 for 2 matrices: muscles and liver in the range from 1 to 500 μg/kg depending on compound. Specificity of the method was tested using blanks. For estimation of the method accuracy samples with known concentrations of sedatives and ß-blockers were analyzed in the conditions of interlaboratory reproducibility with two variable factors. The expanded uncertainties of the measurements range from 10 to 65% with coverage factor of k = 2.