Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
J Chromatogr A. 2013 Nov 22;1317:121-8. doi: 10.1016/j.chroma.2013.07.076. Epub 2013 Jul 24.
By on-line solid phase microextraction with polymer monolith coupled to liquid chromatography-mass spectrometry (SPME-LC-MS), an automated and sensitive method for analysis of the endogenous 28-epihomobrassinolide (28-epihomoBR) in Arabidopsis thaliana was developed in this work. Firstly, a poly(methacrylic acid-co-ethylene dimethacrylate) (poly(MAA-co-EDMA)) monolith was prepared in the capillary and applied in in-tube SPME. Polyethylene glycol (PEG) was used as porogen to adjust the specific surface area and hydrophobicity of the target monolith to get satisfactory permeability, high mechanical strength and good stability. The optimized monolith was then served as extraction medium for analysis of the derivatized 28-epihomoBR in plant samples with the cleanup of matrix and enrichment of desired analyte at the same time. Good linearity was obtained in the linear range of 5-500 ng/L with the coefficient of determination (R(2)) of 0.9996. The limit of detection (S/N=3) of 28-epihomoBR was found to be 2.0 ng/L and the limit of quantification (S/N=10) was 5.0 ng/L. Using this method, the endogenous 0.101 ng/g (FW) 28-epihomoBR was successfully detected from only 400mg A. thaliana samples with satisfactory recovery (80.3-92.1%) and reproducibility (RSD 6.8-9.6%). Comparing with other sample pretreatment methods, this automated on-line SPME-LC-MS method is rapid, sensitive, reproducible and laborsaving.
本文建立了一种在线固相微萃取-液相色谱-质谱联用（SPME-LC-MS）方法，用于分析拟南芥中内源性 28-表高油菜素内酯（28-epihomoBR）。首先，在毛细管内制备了聚（甲基丙烯酸-co-乙二醇二甲基丙烯酸酯）（poly（MAA-co-EDMA））整体柱，并将其用于管内 SPME。聚乙二醇（PEG）用作致孔剂，以调节目标整体柱的比表面积和疏水性，从而获得满意的渗透性、高机械强度和良好的稳定性。然后，将优化后的整体柱用作萃取介质，同时对植物样品进行基质净化和目标分析物的富集，对衍生化的 28-epihomoBR 进行分析。在 5-500ng/L 的线性范围内，得到了良好的线性关系，相关系数（R²）为 0.9996。28-epihomoBR 的检测限（S/N=3）为 2.0ng/L，定量限（S/N=10）为 5.0ng/L。使用该方法，仅从 400mg 拟南芥样品中成功检测到内源性 0.101ng/g（FW）的 28-epihomoBR，回收率为 80.3%-92.1%，重现性为 6.8%-9.6%。与其他样品预处理方法相比，这种自动化在线 SPME-LC-MS 方法快速、灵敏、重现性好、节省劳力。
