Determination Of Plant Hormones By Molecular Imprinting-Solid Phase Extraction-Chemiluminescence Methods

In this paper, a series of flow injection-chemiluminescence （FI-CL） methodscombined with molecular imprinting （MI） and solid phase extraction （SPE）techniques have been developed for the determination of some plant hormonesincluding Indoleacetic acid （IAA） in plants, maleic hydrazide （MH） in soils andvegetables, respectively. The methods are all based on the enhancement of analytes onthe chemiluminescence of the galangin-potassium permanganate-polyphosphoric acid（PPA） system. The present work aims to develop the detection methods for planthormones and to spread the use of the sample pretreatment techniques in CL analysis.This paper consists of two parts.Part One A ReviewChapter one A review on CL analysis, solid phase extraction and molecularimprinting techniqueThe basic principles and the characteristics of CL analysis, MI technique and SPEtechnique, the preparation methods of molecular imprinting polymers, as well as thesample pretreatment techniques used in CL analysis are introduced in this chapter.The development of MI-SPE-CL method is summarized.136references are cited.Chapter two The development of analysis of plant hormonesThe methods for the determination of plant hormones are summarized andreviewed in this chapter. It vistas the development trend of detection methods forplant hormones, and explain the significance of this work.28references are cited.Part Two Chemiluminescence detection of plant hormonesChapter one Solid phase extraction-flow injection chemiluminescencedetermination of indoleacetic acid in ArabidopsisIndoleacetic acid （IAA） in Arabidopsis was extracted with methanol in an ultrasonic bath and purified by solid phase extraction （SPE）, followed by flowinjection-chemiluminescent （FI-CL） detection. The method was based on theenhancement of IAA on the chemiluminescence of the galangin-potassiumpermanganate-polyphosphoric acid system. Under the optimum conditions, the logvalue of relative CL intensity was in proportion to the log value of the concentrationin the range from8.0×10^-9to1.0×10^-7g/mL and from1.0×10^-7to1.0×10-6g/mL,respectively，with a detection limit of2.8×10^-9g/mL（3σ）. The relative standarddeviation （RSD） for the determination of1.0×10^-7g/mL IAA was2.6%（n=10）. Theproposed method has been used for the determination of IAA in Arabidopsis with/and Leukamenin E （an ent-kaurane diterpenoid） and the recoveries were in the rangefrom90.3%to101.0%．Chapter two Determination of maleic hydrazide in soils by flow-injectionchemiluminescenceA flow injection-chemiluminescence （FI-CL） method has been developed in thischapter, based on the enhancement of maleic hydrazide （MH） on thechemiluminescence of the galangin-potassium permanganate-polyphosphoric acidsystem. Under the optimum conditions, the relative CL intensity was in proportion tothe concentration of MH in the range of5.0×10^-53.0×10^-2mg/mL with a detectionlimit of2.6×10^-3mg/mL（3σ）. The relative standard deviation （RSD） for thedetermination of1.0×10^-3mg/mL MH was2.7%（n=7）. The method has beenapplied to the determination of maleic hydrazide in three kinds of synthetic soils（loess, bentonite and kaolin） with the recoveries of92.3¹13.4%.Chapter three Determination of maleic hydrazide in vegetables by molecularimprinting-solid phase extraction-chemiluminescence methodA flow injection-chemiluminescence （FI-CL） method combined with molecularimprinting-solid phase extraction technique has been developed for the determinationof maleic hydrazide （MH） in vegetables. The method was based on the enhancementof MH on chemiluminescence intensity of the galangin-potassiumpermanganate-polyphosphoric acid system. A molecular imprinting polymer （MIP） was synthesized by thermal initiated polymerization using MH as a template molecule,methacrylic acid （MAA） as a functional monomer, ethylene glycol dimethacrylate（EGDMA） as a cross-linker and azodiisobutyronitrile （AIBN） as an initiator. MH invegetables was determined by FI-CL method after it was extracted by solid phaseextraction column stuffed by MH-MIP. Under the optimum conditions, the relativeCL intensity was in proportion to MH concentration in the range from5.0×10^-5to3.0×10^-2mg/mL, with a detection limit of2.6×10^-5mg/mL （3σ）. The relative standarddeviation （RSD） for the determination of1.0×10^-3mg/mL maleic hydrazide was2.7%（n=10）. The proposed method has been applied to determine the contents of MH inPotato, Onion and Garlic with spiked recoveries in the range from95.2%to111.7%,with standard relative deviations （RSDs） of1.8%for Potato,2.4%for Onion and2.1%for Garlic, respectively.