Quantitative Determination of Auramine O in Bean Curd Sheets by Dispersive Solid Phase Extraction with Dynamic Surfaced-Enhanced Raman Spectroscopy

摘要

Dynamic surfaced-enhanced Raman spectroscopy (D-SERS) has been widely applied in chemical analysis due to its simple operation and high sensitivity. A new method was developed for the quantitative determination of auramine O in bean curd sheets using D-SERS. Through the optimization of measurement time interval and determination and stability and other SERS conditions, effective and stable SERS measurements of auramine O were performed during the sample solution evaporation process. Dispersive solid phase extraction was applied to remove as many impurities as possible. Following the evaluation of the spectra, the peak at 1114 cm~(-1) in the SERS spectrum was selected to quantify the auramine O present in the bean curd sheets. A matrix standard curve-external standard method was used to conduct the statistical analysis. The results showed that there was good linearity between the chromatographic SERS peak and the concentration of auramine O across the range from 0.5 to 10mg/L. The correlation coefficient (R~2) was greater than 0.99. At spiked levels of 0.5, 1.0, and 5.0mg/kg, the average recoveries of auramine O in the bean curd sheets were from 92.3% to 96% and the relative standard deviations were from 4.6% to 8.3%. The lowest spiked concentration was determined to be the limit of quantitation. As a consequence, this study provides a new stable, effective, rapid approach for the quantitative determination of auramine O in bean curd sheets.