Detection Of Three Typical Antidepressants By Laser-Induced Fluorescence Method Based On Graphene Oxide Quantum Dots

Antidepressants belong to the emerging contaminants with biological toxicity,and their harm to the environment and human health cannot be ignored.It is necessary to investigate the distribution and level of typical antidepressants in the water environment.Therefore,it is urgent to improve scientific detection technology of antidepressants.In order to meet the detection requirements of simple operation,low cost and low detection limit of antidepressants,this study is based on graphene oxide quantum dots(GOQDs),which are modified into the boron-doped graphene oxide quantum dots(B-GOQDs)by fluorescent probes.Then B-GOQDs combined with capillary electrophoresis-laser induced fluorescence detector(CE-LIF)were used to detect three antidepressants including the fluoxetine,sertraline hydrochloride and paroxetine in water.The main conclusions of this study are as follows:(1)A one-step hydrothermal preparation method of boron-doped graphene oxide quantum dots was established and the preparation conditions of B-GOQDs were optimized.The optimization results are the best hydrothermal temperature of 220°C,the best hydrothermal time of 16 h,the best borax concentration of 40 mg/m L and the best sodium hydroxide concentration of 7 mg/m L.The characterization shows that the B-GOQDs prepared under the optimum conditions still has strong fluorescence at the excitation wavelength of 488nm and emission wavelength of 520nm.Therefore,B-GOQDs can be applied to capillary electrophoresis with laser induced fluorescence detector.(2)Fluoxetine was analyzed and detected based on B-GOQDs prepared by one-step hydrothermal method combined with CE-LIF.Under the conditions that the optimal buffer solution type was mixed micelle buffer solution,the buffer concentration was 40 m M,the buffer p H was 9.5,the best injection time is 10 s,the optimal B-GOQDs concentration is2.0 mg/m L and the derivatization time was 1 min,the standard curve of fluoxetine in the linear range of 0.25～16μM was measured:y=131.93x+869.78(R~2=0.999),and the detection limit was 0.15μM of fluoxetine.The average recovery rate of the actual water sample was 95.5%～108.6%,and the relative standard deviation was less than 4.35%.The results show that this method for the detection of fluoxetine is accurate and reliable.(3)Sertraline hydrochloride was analyzed and detected based on B-GOQDs prepared by one-step hydrothermal method combined with CE-LIF.Through the optimization of detection conditions,the best buffer type was borax buffer solution.The best buffer concentration was 70 m M.The best buffer p H was 12.0.The best injection time was 15 s.The best B-GOQDs concentration was 2.0 mg/m L.And the best derivation time was 4 min.Under the optimal electrophoresis conditions and derivative conditions,the standard curve of sertraline hydrochloride in the linear range of 0.10～12μM was measured:y=181.62x+1071.3(R~2=0.9995),and the detection limit was 0.07μM of sertraline hydrochloride.The average recovery rate of actual water samples was 95.5%～103.7%,and the relative standard deviation was less than 2.24%,indicating that the method of detecting sertraline hydrochloride based on B-GOQDs was reproducible and reliable.(4)Paroxetine was analyzed and detected based on B-GOQDs prepared by one-step hydrothermal method combined with CE-LIF.Under the optimal conditions of borax buffer solution with concentration of 60 m M and p H of 11.5,injection time of 20 s,B-GOQDs concentration of 2.0 mg/m L and derivation time of 6 min,the standard curve of paroxetine was measured in the linear range of 0.10～12μM:y=103.55x+1085(R~2=0.9993),and the detection limit was 0.03μM of paroxetine.The average recovery rate of spiked water samples ranged from 98.1%to 104.1%,and the relative standard deviation was less than3.98%.The detection method was accurate and reliable.