Research On The Rapid Detection Method For Acrylamide In Food

Acrylamide (AA), which has been found in fried and baked starchy foods at high level, has become as a global problem to food safety recently. Long-term exposure to AA may cause damage to the nervous system both in human beings and animals at a certain extent. AA is also considered as a potential genetic and reproduction toxin with mutagenic and carcinogenic properties in experimental mammalians. Therefore, the study on quantitative and rapid detection of AA in food is significant. The manufacture of portable instrument for AA detection has attracted people’s attention. However, the primary methods for AA detection with the drawbacks such as inconvenience and time-consuming could not meet the requirements. In recent years, due to the rapid screening, high-throughput screening and inexpensive cost characteristics, electrochemical and fluorescent techniques have been used for the analysis of large amounts of samples. In this dissertation, based on the interaction between AA and hemoglobin (Hb), an electrochemical technique has been presented for rapid detection of AA. Meanwhile, using a novel AA-derivatization approach based on Hofmann reaction, a convenient, sensitive and low-cost fluorescence detection (FLD) method has been proposed for the AA detection in food samples. A portable instrument was also developed according to this method.There are four chapters in this dissertation.In chapter Ⅰ, the development, mechanisms and toxicity of AA were introduced. Both traditional and recently developed methods for AA detection were summarized. The main content and significance of this dissertation were also discussed.In chapter Ⅱ, a rapid FLD method for AA detection in fried food was developed. AA reacted with hypochlorite in alkaline solution to form a complex with amine group. The product then reacted with fluorescamine to generate a fluorescent compound with the maximum emission wavelength at 480 nm when excited at 385 nm. There was a good linear relationship between the AA concentration and the fluorescence intensity of the system. The results of the proposed method for the AA detection in food samples at the ultra-trace level were consistent to those obtained by Industry Standard. This method was successfully applied in rapid determination of AA with simple operation and less time-consuming.In chapter Ⅲ, based on the FLD method, a portable instrument for rapid AA analysis was developed. This instrument displays some advantages such as speediness, sensitivity, accuracy and less time-consuming. The developed portable instrument possesses miniaturized design, portable, stable performance and reliable quality, indicating promising practical applications.In chapter Ⅳ, based on our previous research, three-dimensional N-doped graphene/hemoglobin (3D N-RGO/Hb) was prepared by hydrothermally assembled method. Because of its excellent electrical conductivity, high surface area, biocompatibility and mechanical properties,3D N-RGO was used as support material of Hb, and a 3D N-RGO/Hb modified glassy carbon electrode (GCE) was developed for the detection of AA. Differential pulse voltammogram (DPV) results showed that the 3D N-RGO/Hb modified GCE presented highly sensitive and stable sensing characteristics for AA detection. These results indicated that the proposed method was promising for the development of novel electrochemical sensing for AA detection.