A sample preparation method from livestock products for quantitative apramycin measurement by LC-MS/MS

Abstract

This study aimed to develop a preparation method for apramycin residue in livestock products for liquid chromatography–tandem mass spectrometry (LC-MS/MS). Apramycin was extracted from samples via alkaline hydrolysis or with trichloroacetic acid (TCA) in the presence of n-hexane (hexane). Next, matrix components were removed from the extracted apramycin using two types of hydrophilic-lipophilic balanced (HLB) solid-phase extraction (SPE) cartridges, and apramycin was retained with strong cation-exchange SPE cartridges. Apramycin recovery from the extract was evaluated using bovine muscle, liver, and fat samples with apramycin at the maximum residue limit-value (muscle and fat: 0.5 ppm, liver: 5 ppm). The recovery rate of alkaline hydrolysis extraction was 75.5-90.1% and hexane-TCA extraction was 77.3-92.6%, demonstrating that this method could sufficiently remove matrix components that would affect the measurement, as indicated by guidelines of the Ministry of Health, Labor and Welfare. The method examined in this study is effective for apramycin residue sample preparation in livestock products for quantitative LC-MS/MS measurements.