Development Of An On-site System For Rapid Detection Of PAHs In Coastal Zone Water Samples

Recently, crisis on environment brings rigorous and increasing challenges to us, thedevelopment of new analytical method and tools come to be one of the important ways tocope with them. Due to its simple preparation, good water solubility, facile monomers anddiverse applications, hydrophilic molecularly imprinted polymers are finding theirimportant application in construction of sample pretreatment and lowering the detectionlimit. Ultraviolet-visible (UV-vis) spectrophotometry with properties of high sensitivity,good selectivity, wide application, easy accessibility and facile miniaturization, is a verymature qualitative, quantitative and structural analysis method. Since its generation,UV-vis spectrophotometry has been experienced extensive attention in the field of biology,medicine, chemistry, material and energy. Based on their unique properties of hydrophilicmolecularly imprinted polymers and UV-vis spectrophotometry, an on-site rapid detectionsensor system copied with the coastal zone water sample was constructed, and furtherexamined for their application in environmental analysis. Details are summarized asbelow:(1) The establishment of the separation and enrichment method of trace levelbenzo[a]pyrene in water simulated samplesAfter proper selection of suitable auxiliary monomers, the molecularly imprintedpolymers were synthesized based on phenanthrene,4-vinylpyridine, divinylbenzene astemplates, functional monomers and crosslinkers, respectively. The hydrophilicmolecularly imprinted polymers (H-MIPs) were modified by the former polymers andfurther applied to the solid phase extraction with high selectivity and good separationability. Due to the role of swelling adsorption and lipophilicity, the selective retention ofbenzo[a]pyrene by the H-MIPs was improved. Results showed that the selective recoveryrate of benzo[a]pyrene was94%. The preparation of H-MIPs was expected to be apretreatment strategy of large volume water sample and applied to the separation andenrichment for other nonpolar organic pollutants. (2) The establishment of UV-vis spectral analysis method of trace level benzo[a]pyrene inwater simulated samplesBased on the investigation on selectivity to16polycyclic aromatic hydrocarbons, thelargest molar absorption coefficient and biggest absorbance for benzo[a]pyrene at382nmwere found even when the others dissolved completely. This performance met thedetection requirements satisfactorily. On this basis, according to the molar absorptioncoefficient, the spectrum background interference caused by sodium salt and chlorophyllin the simulated water sample was excluded. And the method of increasing auxiliarymonomer was adopted to prepare new polymer and its application to the solid phaseextraction of detection of benzo[a]pyrene in the presence of humic acid was madesuccessfully. Due to the simple operation in the detection with rapidness, high efficiencyand facile automation for this method, it is expected to be utilized in wider fields.(3) The establishment of the on-site rapid detection sensor system for organic pollutantsin coastal zone water samplesSampling, pretreatment, separation, enrichment and detection were set as a wholesystem, and their operation were all controlled by computer. Due to the functionalintegration, the total test time was less than1hour, which fully reflected the advantages ofautomation, short testing cycle and less resources consumption for the on-site rapiddetection technology. The successful development of this prototype will provide a largenumber of field testing data for in-depth study on the process of migration andtransformation rules of organic pollutants in the environment, and provide technical andtheoretical support for improving the state of the environment.