Development and evaluation of a semi-automatic single-step clean-up apparatus for rapid analysis of 18 antibiotics in fish samples

Here we report a novel semi-automatic pre-treatment apparatus to fulfill a single-step clean-up aim for rapid quantification of 18 antibiotics in fish samples. Trimethoprim and 17 sulfonamides were extracted from fish samples by acetonitrile solution based on ultrasonic-assisted extraction. Cheap analytical filtration syringe (CAFS) clean-up column was used to fulfill single-step clean-up of the extract which was set on the developed semi-automatic clean-up apparatus. This semi-automatic clean-up apparatus is quite convenient for single-step purification by precisely controlling the flow rate of the extracts, in which up to 10 samples can be purified in parallel at one time. The time needed to clean sample was only about 2 min per 10 samples. Type of compatible purification column ranged from 1 mL (inner diameter × length, 5.6 × 55 mm) to 12 mL (inner diameter × length, 15.6 × 83 mm). The apparatus also did not need additional gas source such as nitrogen or air. After purification, the analytes were simultaneously separated and quantified by high-performance liquid chromatography/quadrupole-linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS). The limits of detections ranged from 0.5 to 1.0 μg kg−1, and the limits of quantifications ranged from 1.0 to 5.0 μg kg−1. All the recoveries ranged from 81.39% to 116.01%. Intra-day and inter-day relative standard deviations (RSDs) were lower than 14% for all analytes.