Determination of 10 Plant Growth Regulators in Bean Sprouts by Sequential Cleaning-Gas Chromatography-Mass Spectrometry

A sequential clean-up method was developed for the quantification of 10 plant growth regulators in bean sprout by the gas chromatography / mass spectrometry( GC / MS). The analytes were firstly extracted by the acided acetonitrile. Extraction was concentrated and re-dissovled by methanol. Then,it was divided to two aliquots. One of that was analyzed for 2,4-D-butyl ester and 2,4-D-ethyl ester after the purification by QuECHERS cartridge. Another one was treated by MCS solid phase extraction column including diverse eluting steps. After eluting by 5 mL methanol,composition 1 was obtain,concentrated,and methyl esterified by 10% boron trifluoride methanol solution. The treated extract was used for the determination of 4-chlorophenoxy acetic acid,β-naphthyl acetic acid,2,4-dichlorophenoxy acetic acid,indole acetic acid and indole butyric acid. Composition 2 collected by eluting with 5 mL 5% amonium methanol was used for the determination of paclobutrazol, Kinetin, 6-Benzylaminopurine. The clean-up procedures are designed according to different chemistry properties of these plant growth regulators. The results showed that after spiking of 0. 01- 0. 1 mg / kg selected plant growth regulators,average recovery ranged from 70. 0% to 93. 2% and relative standard deviation were 5. 2%- 12. 3%. Limit of quantification( LOQ S / N≥10) and limit of detection( LOD S / N≥3) were 0. 01- 0. 025 mg / kg and 0. 003- 0. 008 mg / kg respectively. The developed purification method is easy,fast and accurate,and can be applied to routine test of plant growth regulators in bean sprout.