Investigation And Application Of The Combination Of High Performance Liquid Chromatography And Surface Enhanced Raman Spectroscopy

Surface enhanced Raman spectroscopy(SERS) has been one of the most sensitive structural identification technique for trace detection. On this basis, coupling high performance liquid chromatography(HPLC) and SERS through a proper way can provide a high sensitive analysis technique for both separation and structural detection. In this dissertation, a nanoparticles-modified capillary, a kind of SERS active substrates, was developed to build a HPLC-SERS system, on-line separation and detection of some different kinds of mixtures were finished through this combined system. The main results have been listed below:1. Finished the functionalization of the capillary in HPLC-SERS system. Prepared Au and Au@Ag nanoparticles. The nanoparticles were immobilized onto the inner wall of a capillary through a self-assembly way. The modified capillary showed good SERS activity. By the pretreatment of Cl- solution, this kind of substrates could have a better SERS performance. The results showed that the functionalized capillary could connect to HPLC, realizing high sensitive SERS detection.2. After the construction of HPLC-SERS system, different kinds of binary mixture samples(4,4-bipyridine and 1,4-benzenedithiol; 4,4-bipyridine and 4-aminothiophenol) and a quanternary mixture(4,4-bipyridine, 4-cyanopyridine, 4-mercaptobenzoic acid and 1,4-benzenedithiol) were successfully separated and detected. All results showed that the HPLC-SERS system had a satisfactory separation efficiency and could detect different molecules at the corresponding time.3. The separation and SERS detection of thiram, a typical kind of pesticides, was finished through HPLC-SERS system. The detection limit could reach 10-7 mol?L-1, lower than normal HPLC system. A solution containing 4,4-bipyridine and thiram was also checked as a mixture sample and gave a satisfied result. To expand this HPLC-SERS technique to real application, a sample of orange peel containing thiram was put forward and finally SERS spectra of thiram were recorded, proving a well real application prospect.4. Combined with normal HPLC system, SERS could make up some disadvantages of UV detector. SERS spectra could explain the undefined chromatogram. Also by providing detailed structural information of the separated liquids, we could evaluate the separation efficiency and eliminate fake signal interference.