| Malachite green and its metabolites are potentially carcinogenic, teratogenic and mutagenic, which are monitored for the safety of food or water. At present, the main detection methods of malachite green （MG） are liquid chromatography and liquid chromatography tandem mass spectrometry. Surface enhance Raman scatting （SERS） is a new sensitive quantitative analytical technique, which has been steadily developed recently, and has been applied widely to the study of life and nanometer materials, etc. However, there are no reports discussing the determination of MG in water or fish by SERS. In this work, a sensitive, selective, simple and rapid method based on SERS was established for the determination of MG. The main research conclusions are presented as the following:1. Three different particle sizes of silver colloids were made by chemical reduction, and characterized by UV-visible absorption spectroscopy and transmission electron microscopy （TEM）. The results showed that various enhancement effects were obtained by three silver colloid with different diameter, and the effect used by the silver colloid prepared through hydroxylamine hydrochloride was the best.2. The detction conditions of malachite green in water were optimized by SERS: the colloid made by hydroxylamine hydrochloride was diluted to 0.5 times, then 0.15M NaCl solution and malachite green aqueous solution were added to the colloid （pH=4）. Under these conditions standard aqueous solution of malachite green detection limit was 1×10-6m/L. In the actual water sample detection limit of malachite green was related to the cleanliness of water samples. In sewage water, detection sensitivity of MG was 5×10-5g/L.3. Optimizes detction conditions of LMG in ACN by SERS: the colloid made by hydroxylamine hydrochloride was concentrated to 1.25 times, and 0.15M NaCl solution and LMG in ACN were added to the colloid （pH=4）. Under these conditions ACN solution of malachite green detection limit was 1×10-6g/L, which was 4×10-7 times higher than conventional Raman spcetroscopy.4. Established quantitative detection of MG and malachite LMG in ACN. Under their respective optimal conditions, the MG standard ACN solution detection limit was 1×10-6g/L; the linear range was 5×10-6g/L -8×10-5g/L; linear correlation coefficient was 99.69 %; relative standard deviation was 0.11%-5.2%（n=6）. the LMG standard ACN solution detection limit was 5×10-6g/L; the linear range was 1×10-5/L-1×10-4g/L; linear correlation coefficient was 99.15 %; relative standard deviation was 1.8%-7.8%（n=6）.5. Established quantitative detection of MG and malachite LMG in fish. The MG in fish detection limit was 30μg/kg; the linear range was 100μg/kg-800μg/kg; linear correlation coefficient was 99.42%; relative standard deviation was 1.6%-5.2%（n=6）. the LMG in fish detection limit was 50μg/kg; the linear range was 200μg/kg-1000μg/kg; linear correlation coefficient was 99.29 %; relative standard deviation was 0.9%-2.3%（n=6）. |
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