| In this study, a combination of homogeneous liquid–liquid extraction and dispersive liquid–liquid
microextraction based on solidification of a deep eutectic solvent has been utilized as an efficient
method for the extraction of three widely used antibiotics (oxytetracycline, penicillin G, and tilmicosin)
from sausage samples. In this method, initially the antibiotics are extracted from the powdered sausage
sample into acetonitrile and then, to concentrate the analytes and achieve a high sensitivity, the obtained
acetonitrile is mixed with an extraction solvent (a newly synthesized water-immiscible deep eutectic
solvent with a melting point near room temperature), and the obtained mixture is rapidly injected into
deionized water. In the next step, the mixture is transferred into an ice bath and the solidified extraction
solvent containing the analytes is removed and dissolved in ACN. For quantitative analysis, this phase is
taken and injected into an ion mobility spectrometer which operated in the positive mode and is
equipped with a continuous corona discharge ionizer. This instrumental technique characterizes
molecules based on the gaseous phase mobility of their ions formed at ambient pressure and under an
electric field. Under the optimum conditions, limits of detection and quantification were achieved in the
ranges of 1.52–2.73 and 5.1–9.1 ng g1, respectively. The relative standard deviations were less than 8%
for intra- (n ¼ 6) and inter-day (n ¼ 4) precisions at a concentration of 20 ng g1 of each analyte. Finally,
the proposed method was applied to the analysis of the studied antibiotics in fifteen different sausage
samples marketed in Tabriz, Iran. Oxytetracycline was determined in three of the studied sausage samples. |