Study On The Detection Of Edible Vegetable Oils Using Excitation-emission Matrices

Edible oil is an essential ingredient in people's daily catering.It can provide important lipids to the body and help people to supplement the trace amounts of organic matter they need.In recent years,quality problems of edible vegetable oil often occur,such as vegetable oil adulteration,toxin residues and gutter oil incidents,which seriously violate relevant laws and threaten consumers' lives and health.Among many detection methods of edible vegetable oil,three-dimensional fluorescence spectrometry has attracted much attention due to its simple operation,strong selectivity,high sensitivity,and low sample consumption.The experimental object of this study is edible vegetable oil.The three-dimensional fluorescence spectroscopy and chemical statistics methods are used to complete the detection of adulteration and pesticide residues of edible vegetable oils.The main contents as follows:(1)The original three-dimensional fluorescence spectrum data of six edible vegetable oils were obtained by steady-state fluorescence spectrometer FS920.The position,intensity and quantity of fluorescence peaks were compared.The information of the components of vegetable oils corresponding to different fluorescence peaks in the fluorescence spectrum was given.(2)The spectral data were processed by chemical statistics.Parallel factor algorithm(PARAFAC)and alternating trilinear decomposition(ATLD)were introduced into the detection of adulteration in edible vegetable oil.Using olive oil as base oil and soybean oil as adulterated oil,adulterated samples with different volumetric concentration were allocated to realize the qualitative analysis.The results show that both PARAFAC and ATLD algorithms can well realize the qualitative analysis of adulterated samples.When fitting the two-factor resolution spectra with the normalized spectra of olive oil and soybean oil,the ATLD algorithm has a higher coincidence between the factor-2 resolution spectra and the normalized spectra of olive oil.Furthermore,the reliability of ATLD model was verified by olive oil,peanut oil adulterated samples and olive oil,peanut oil and soybean oil adulterated samples.(3)The application of ATLD algorithm in the detection of pesticide residues in edible vegetable oils was analyzed.Taking sesame oil as the experimental object,the pesticide residues in sesame oil were analyzed qualitatively and quantitatively by configuring different concentrations of sesame oil with methomyl.The results showed that the ATLD algorithm could realize the qualitative and quantitative detection of sesame oil pesticide residues.The average recovery rate of sesame oil was 99.53%,the root mean square error(RMSE)was 0.057,and the average recovery rate of methomyl was 97.31%,and the RMSE was 0.041.