Determination Of Plant Growth Regulators By High Performance Liquid Chromatography

Plant growth regulators(PGRs) can regulate and control the different stages of plant growth,and the usage of PGRs have been of the essence in the modern agricultural development. Therefore, it makes “Artificial regulation” of plant growth come true. However, the plant growth regulators residues in crops and drinking water can weaken human immune system and cause harm in bones. The plant growth regulators residues in the international trade of agricultural products have become the restrictions. Currently, more and more researches tend to pay close attention to the plant growth regulators. High-performance liquid chromatography has been employed for quantitative detection of plant growth regulators in routine analysis. However, the matrix effects plagued seriously the accuracy of HPLC-MS/MS methods, and it was difficult to obtain reliable quantitative results.For high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) analysis, isotope-labeled analytes are often used as internal standards to solve this problem, but the isotopic internal standards are expensive and sometimes not commercially available. Fortunately, the isotope-coded derivatization can give a series of isotope-labeled analytes, which could greatly reduce the cost of isotope internal standards. For high performance liquid chromatography-fluorescent detection(HPLC-FLD) analysis, some endogenous fluorescent substances may interfere the detection of PGRs. By used of some fluorescent derivatization reagent, the phenomenon of fluorescence resonance energy transfer(FRET) can be observed in the PGRs derivatives. The FRET provided superior Ex/Em wavelength can facilitate accurate determination of PGRs with less interference and low noise. The main works are as follow.Chapter One: we reviewed the background of Plant growth regulators and fundamental theoretical knowledge of high-performance liquid chromatography, mass spectrometry and fluorescent detection, as well as matrix effects and fluorescence resonance energy transfer.Chapter Two: A pair of isotope-coded derivatization reagents, d0-10-methyl-acridone-2-sulfonyl piperazine(d0-MASPz, light form) and d3-10-methyl-acridone-2-sulfonyl piperazine(d3-MASPz, heavy form) has been synthesized and identified.Chapter Three: A method for determination of 6 plant growth regulators by HPLC-MS/MS coupled with isotope-coded derivatization was developed. The carboxylic plant growth regulator standards and real samples were derivatized by d0-MASPz and d3-MASPz, respectively. The mixed derivatization solution was subjected to HPLC-MS/MS analysis. The proposed method can well meet the requirement for determination of plant growth regulators in fruits and vegetables, and provide technical support for regulating the use of plant growth regulators.Chapter Four: d0/d3-MASPz derivatization reagents have been used in the determination in 12 phenoxyalkanoic acids herbicide. The established isotope-coded derivatization-HPLC-MS/MS method was applied for determining herbicides in environmental water. The results indicate that it has advantages over previous methods. It is a potential method for evaluation of phenoxyalkanoic acids herbicide environmental water in routine analysis.Chapter Five: the BECTS and Dans-Pz were used as derivatization for labeling plant growth regulators. After indoles carboxylic acids, naphthoxyacetic acid and naphthylacetic acid were derivatized, the derivatives can occur fluorescence resonance energy transfer(FRET) between indole(or naphthyl) moiety and benzocarbozole. A HPLC-FRET-FLD methods for sensitive dermination of plant growth regulators were developed by select donor excitation wavelength and acceptor emission wavelength. The proposed methods can greatly eliminate the interference and reduce noises.