Study On New Method For The Determination Of Some Heavy Metal Ions And Polycyclic Aromatic Hydrocarbons

Environmental pollutions have caused serious harm to our life and development. Heavy metal ions and polycyclic aromatic hydrocarbons are two important environmental pollutants, and they are the focuses when we mention the environment pollution. Although some of heavy metal ions belong to essential metal ions to human bodies, due to degradability of these ions, they will seriously affect our health as other unnecessary heavy metal ions after accumulation. The nitropolycyclic aromatic hydrocarbons (nitro-PAHs) is a kind of potential mutagenic and carcinogenic environmental pollutants, it is easy to be absorbed onto environmental particles including PM2.5 and gradually to be accumulated. PM2.5 particles with nitro-PAHs can easily enter the human lung and blood, which is extremely harmful to the human body health. Therefore, to establish the rapid detection methods for heavy metal ions and Nitro-PAHs have very important significance.In the text we designed and synthesized a series of rhodamine B, fluorescein and carbazole derivative as the Cu2+ and Cr3+ fluorescence probe. Their spectral characteristics and the recognition performance to metal ions have been systematically researched and we also obtained some achievements. In addition, we established a rapid, sensitive and selective new method for determination of nitro polycyclic aromatic hydrocarbons and successfully applied in the detection of nitropolycyclic aromatic hydrocarbons onto PM2.5 particles.The main work contents and results were as follows:1. In the text, the pollution sources of heavy metal ions and nitro-PAHs and their hazards to our healthy have been expounded, we also outlined the research progress on the test methods of heavy metal ions and nitro-PAHs so far, especially the progress of fluorescent probe detection for the purposes of this thesis involving Cu2+ and Cr3+ were introduced in detail.2. A novel fluorescein derivative furfuraldehyde fluorescein hydrazone (FFH) was synthesized by reacting fluorescein hydrazide with furfuraldehyde and evaluated as a fluorescent probe for Cu2+. The presence of Cu2+ results in an obvious new band appeared at 502nm in the UV-vis absorption spectra of FFH, and the color of the solution changed from colorless to yellow together. This change is attributed to the spirocycle form of FFH opened via coordination with Cu2+ in a 1:1 stoichiometry and their association constant is determined as 6.1×104 L·mol-1. Experimental results indicate that the FFH can provide a rapid, selective and sensitive response to Cu2 with a linear dynamic range 6.6-330 μmol·L-1.3. A novel rhodamine derivative 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH) was synthesized by reacting rhodamine B hydrazide with 3-bromo-5-methylsalicylaldehyde and developed as a new colorimetric probe for the selective and sensitive detection of Cu2+. The experimental results showed that BMSRH coordinated with Cu2+ in a 1:1 stoichiometry and their association constant is determined as 3.2×104 L·mol-1. Experimental results indicate that the BMSRH can provide a rapid, selective and sensitive response to Cu2+ with a linear dynamic range 0.667-240 μmol·L-1. Common interferent ions do not show any interference on the Cu2+ determination.4. A novel carbazole derivative N,N’-bis(9-ethyl-9H-carbazol-3-yl)-(ethane-1,2-diamine) was synthesized by reacting 3-amino-9-ethylcarbazole with glyoxal. The strong fluorescence emission at 438 nm of the derivative is effectively and selectively quenched by Cr3+. A 1:1 complex is formed between the carbazole derivative and Cr3+ and their association constant is 1.4×104L·mol-1. The results indicate that the carbazole derivative can provide a rapid, selective and sensitive response to Cr3+in a linear dynamic range 1.0-20 μmol·L-1 with a limit of detection of 0.10 μmol·L-1 at pH 7.4. Common interferent ions do not show any interfere on the Cr3+ determination.5. In the text, we successfully synthesized a material of magnetic oxidized graphene composites (MAOG) by two steps. MAOG was served as both absorbent in the pretreatment of sample and matrix in MALDI-TOFMS analysis. With the aid of an external magnetic field MAOG can be easily separated from the sample after enrichment and be directly analyzed by MALDI-TOFMS without any interference. We established a simple and rapid method for detecting nitropolycyclic hydrocarbons (nitro-PAHs) by using the synthesized magnetic graphene composites as adsorbent for enrichment and matrix for MALDI-TOFMS analysis. The method also was successfully applied in the detection of nitro-PAHs in PM2.5 sample.