Simultaneous determination of kasugamycin and validamycin-A residues in cereals by consecutive solid-phase extraction combined with liquid chromatography–tandem mass spectrometry

ABSTRACT

Two polar aminoglycosides, kasugamycin and validamycin-A, were determined in cereals (brown rice, wheat and corn) by high-performance liquid chromatography–tandem mass spectrometry. The analytes were extracted from samples using methanol and water (70:30, v/v) at pH 5.5, purified using both a hydrophilic–hydrophobic-balanced cartridge and a strong cation-exchange cartridge, and then analysed using multiple reaction monitoring in positive electrospray ionisation mode with a special ReproSil 100 C₁₈ high-performance liquid chromatography column. This newly proposed method yielded good sensitivity and excellent chromatographic performance. The limits of quantification for kasugamycin and validamycin-A were 4.1 µg/kg and 1.0 µg/kg, respectively. The recoveries for both compounds at three fortification levels (4, 100 and 500 µg/kg for kasugamycin; 1, 10 and 100 µg/kg for validamycin-A) ranged from 75% to 110%, and the relative standard deviations were below 15%.

KEYWORDS:

• Kasugamycin
• validamycin-A
• residue
• cereals
• high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS)

Acknowledgements

This work was financially supported by the Innovation and Achievement Transformation Projects (2014ZZCX02703) of Shandong Province and the Science and Technology Achievement Cultivate Project (2015CGPY04) of Shandong Academy of Agricultural Sciences.

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This work was supported by the Innovation and Achievement Transformation Projects (Shandong Academy of Agricultural Sciences [2015CGPY04]) of Shandong Province (Shandong Academy of Agricultural Sciences [2014ZZCX02703]) and the Science and Technology Achievement Cultivate Project of Shandong Academy of Agricultural Sciences.