Preparation of a new cellulose magnetic molecularly imprinted polymer micro-spheres to extract and analyze the indole-3-acetic acid in plant tissues.

The plant hormone auxin plays a fundamental role in the growth and development of plants. However, because of its low concentration and many other interfering substances in plant tissues, the determination of auxins is still a challenging problem. To solve this problem, a kind of novel cellulose magnetic molecularly imprinted polymer micro-spheres (CMMIPs) was prepared by entrapment technique in this study. The Fe3O4 paramagnetic particles acted as the core and were modified by cellulose, silanized β-Cyclodextrin (β-CD) and 4-Vinylpyridine (4-VP), were adopted for the specific selective recognition cavities. The CMMIPs were characterized with scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). High performance liquid chromatography (HPLC) was used for the determination of IAA in plant tissues. Based on the evaluations, the results showed that the CMMIPs possess porous surface appearance, narrow range particle size distribution and fine roundness. The sizes of most CMMIPs were within the range of 50-180 μm. And they can extract IAA more efficiently than those cellulose magnetic non-imprinted polymer micro-spheres (CMNIPs). CMMIPs can be recycled and preserved for a long time. Effective linear ranges for IAA was in the range of 1.00-100.0 μg L-1, and the effective detection limits was 4.5 μg L-1. The adding standard recovery was about 95%, and the relative standard deviations (RSD) was <5% for standard sample. The performance analysis was also estimated by seeds from three different plants, pea, rice and wheat. Recoveries were ranging from 73.2-80.1%, and the RSDs were from 3.8% to 13.3%. The results show that it was a reliable analytical method based on CMMIPs extraction combined with HPLC.