Determination of trace antibiotics in water and milk via preconcentration and cleanup using activated carbons

Sonolytic degradation kinetics and mechanisms of antibiotics in water and cow milk

“…Since the model ABX are non-volatile substances (the boil points of the model ABX are in the range of 548.5–817.1°C, Table S5 [14] , [37] ), thus they are mainly oxidized in bulk solution or at the interface of bubbles [38] . The hydrophobic CEF were mainly oxidized near the bubbles, where the concentration of free radicals is highest among the three reaction zones.…”

“…A centrifuge (Allegra 64R Benchtop Centrifuge, Beckman Coulter, Italy) with a maximum rotation speed of 26,000 rpm and a centrifuge (L530, Xiangyi, China) with a maximum rotation speed of 4,200 rpm were used to separate the supernatants from milk samples. An HPLC system (Waters Corp., Milford, MA, USA) was used for ABX determination as described in previous work [37] . A UPLC-MS/MS system (Acquity TQD LC-MS/MS System, Waters Corporation, Milford, MA, USA) equipped with a Kinetex C18 column (150 × 4.6 mm, 5 μ m) coupled with a C18 cartridge (H1) was used to determine the intermediates of ABX degradation.…”

“…The collected water and milk samples were pretreated by enrichment and cleanup with AC-SPE-HPLC as described in previous work [37] . For the analysis of ABX in milk with high concentration (initial concentration: 192.8 μ M), 1 mL ABX-contained milk samples were collected periodically and deproteinized by mixing with MeCN (1:1, v:v ) and centrifuged at 4,200 rpm for 10 min.…”