ABSTRACT
There are some common analysis challenges in the hormone detection in agriculture science, including matrix interference, complicated sample preparation, poor reproducibility, trace analyte content. An automated on-line SPE and innovative fast polarity switch analysis method employing dual-gradient liquid chromatography ( DGLC ) coupled with tandem mass spectrometry ( DGLC-MS/MS ) was established and validated for the simultaneous determination of gibberellic acid ( GA3 ) , indole acetic acid ( IAA ) , zeatin ( ZT) and abscisic acid ( ABA) in the soybean plant ( leaf, grain and pod) . The method was applied in the actual sample detection successfully. In order to acquire higher sensitivity, recovery, stability and precision, some conditions including SPE column, analytical column, mobile phase, additive etc were optimized according to the selection and retain of hormone. Beans were cryogenically grinded by liquid nitrogen, extracted by 80% methanol, certrifugatel and dilluted with water, and then injected directly. Samples were transported and gradient eluted on the analytical column Acclaim PA2 by 0 . 1% formic acid in water and methanol, after retaining and separation on the SPE column Hypersep Retain AX. All analytes were detected in selection reaction monitoring ( SRM) mode in both positive and negative channels. The quantification was based on linear regression. The linear ranges of GA3, IAA and ZT were 0. 1-50 μg/L with the LOQ of 0. 0002 μg/g, and the linear of ABA was 0. 5-50 μg/L with the LOQ of 0. 0010μg/g. The recoveries of four kinds of plants hormones were 76 . 1%-93 . 5%, and RSDs were 0 . 82%-6 . 02% at low ( 0 . 8 μg/L ) , medium (4. 0μg/L) and high (40μg/L). The results noted that the content of ABA in seeds was apparently higher than others. This method could be used for the rapid and accurate detection of hormone in different parts of soya beans.