[Determination of the plant growth regulators in batatas by matrix solid-phase dispersive extraction and high performance liquid chromatography with tandem mass spectrometry]

An analytical method based on matrix solid-phase dispersive (MSPD) extraction and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the determination of forchlorfenuron, 6-benzylaminopurine (6-BA), N-(2-ethylhexyl)-5-norbornene-2,3-dicarboximide (MGK 264) and paclobutrazol in batatas. The samples were dispersed with silica by grinding, and then extracted with methanol. The determination was carried out on a Thermo hypersil GOLD C18 column (150 mm×2.1 mm, 5 μm) in gradient elution with mobile phases of methanol and ammonium formate (5 mmol/L, containing 0.1% (v/v) formic acid) and detected with tandem mass spectrometry using selected reaction monitoring (SRM) mode. The quantification was performed using external standard calibration, and the calibration curves were performed in the ranges of 10.8-216.0 ng/g (forchlorfenuron), 10.8-216.0 ng/g (6-BA), 12.5-250.0 ng/g (MGK 264), 10.2-204.0 ng/g (paclobutrazol) with the correlation coefficients larger than 0.96. The limits of quantification (LOQs) were 0.1-0.3 ng/g. The spiked recoveries at the levels of 50, 100 and 200 ng/g of these four plant growth regulators were in the range of 85.3%-116.0%, and the relative standard deviations were 0.6%-22.7%. This method has advantages of simple operation and good accuracy, and can be used for the quantitative determination of forchlorfenuron, 6-BA, MGK 264 and paclobutrazol in batatas.