The Study Of Solid Phase Extraction And Solid Phase Microextraction Technique In Important Tobacco Components Analysis

Due to the requirement of development Chinese tobacco industry and the evaluation of representative harmful compounds in tobacco leaf and cigarette smoke, the investigation of determination method for heavy metal ions, phenols, aromatic amine, polycyclic aromatic hydrocarbons in tobacco and cigarette smoke were necessary. By establishing some new sample preparation devices and technologies, the sensitivity and selectivity of analytical method for heavy metal ions, phenols, aromatic amine and polycyclic aromatic hydrocarbons analysis were improved, and the analytical procedure were simplified. The simple and accurate analytical methods for harmful compounds in tobacco and cigarette smoke were developed.Four main aspects were included in the dissertation:(1) Seven porphyrin reagents using as pre-column derivation reagent for the HPLC determination of nickel, tin, lead, cadmium, and mercury were studied. The nickel, tin, lead, cadmium, and mercury ions were pre-column derivatized with T4-APP to form hydrophobic chelates. These chelates were enriched by solid phase extraction (SPE) with Waters Xterra ^TMRP₁₈ cartridge and the enrichment factor of 50 was achieved. This provided a new method to the determination of nickel, tin, lead, cadmium and mercury in tobacco leaf and cigarette smoke by high-performance liquid chromatography and got good results.A chromogenic reagent p-sulfobenzylidene-thiorhodanine (SBDTR) was synthesized. The SBDTR and its metal chelate has good water solubility because the SDBTR has a hydrophilic radical (-SO3H). This overcomes the disadvantages that rhodanine reagents have poor water solubility. Based on this, the sensitivity for mercury determination was also improved.By the synthesis of derivation reagent and the application of solid phase extraction in spectrophotometric and HPLC determination, the advantages of solid phase extraction and instrumental analysis were combined. The sensitivity and selectivity of analytical method were improved. The heavy metal analytical method in tobacco leaf and cigarette smoke was achieved with HPLC UV-Vis detector.(2) To determination of phenols, the two-step solid phase extraction method was studied. In alkaline medium (pH≥12.5), the phenols existed as anion speciation and have a strong hydrophilicity. They can not be retained on the reversed phase SPE cartridge. However, in the weak acid medium (pH=2.0～3.5), the phenols existed as neutral molecules speciation and have hydrophobicity. They can be retained on the reversed phase SPE cartridge. Based on this character, the phenols can be enriched and purified by the two-step SPE method. The selectivity and sensitivity for phenols determination was greatly improved. The key phenols can be separated completely with in 2 min.(3) The aromatic amines were derivated with o-methoxyphenol to form azo dyes. By derivation, the retention and spectral characters of aromatic amines were changed. It is easy to be separated from interference components and enriched by solid phase extraction. The sensitivity and selectivity of the method were improved. By on-line solid phase extraction the derivation techniques also solve the disadvantage of peak tailing and peak broadening when large volume of sample was injected. The determination of aromatic amines in mainstream smoke by on-line solid phase extraction and high performance liquid chromatography was achieved.(4) A novel graphite SPME fiber was firstly investigated for polycyclic aromatic hydrocarbons determination. Because the size in layer of graphite is homologous with benzene ring thickness, the graphite SPME fiber give a large adsorption surface area to the polycyclic aromatic hydrocarbons. The results show that the graphite SPME fiber has high selectively to polycyclic aromatic hydrocarbons. It is especial suitable to extract polycyclic aromatic hydrocarbons in complex matrices. The graphite SPME fiber can directly extract the analytes in organic solution, avoid the sample transfer in the sample preparation procedure. The graphite SPME fiber avoided the disadvantage that the commercial SPME fiber can not use in the organic solvent system and expanded the application fields of SPME.