The Establishment And Application Of A Detection System Based On Membrane Enrichment And Surface Fluorescence Spectrometry

The solid phase spectroscopy has been rapid developed because it can improve the detection sensitivity and make full use of the advantages of spectroscopy. In this paper nylon membrane was selected as an enrichment matrix to establish a detection system based on membrane enrichment and surface fluorescence spectrometry. Choosing a suitable membrane for efficient enrichment of the analytes, the concentrated analytes on the membrane surface are detected with the solid surface fluorescence detection system directly without elution. This method is simple and high sensitive. Compared with the liquid fluorescence detection technique, there are so many differences. So the basic test parameters (including the photomultiplier tube voltage, slit widths and the incident angle) and the pore size of nylon membrane have been optimized at first.Then the detection system developed is used to the quantitative analysis of2-naphthalene sulfonic acid and2-naphthol at the optimal experimental conditions(pH, filtration volume, flow rate). For2-naphthalene sulfonic acid, in the range from1.Ox10"3to0.16mg/L, the standard curve equation is y=76044x+971.04(R2is0.9957), and the estimated limit of detection(LOD) is0.855х10-3mg/L. The relative standard deviation is7.62%(n=7) at concentration level of0.02mg/L. The sensitivity of2-naphthalene sulfonic detection increases at least50times compared to the conventional liquid fluorescence detection and30times compared to the reported method of RP-HPLC. For2-naphthol, in the range from5.0х10-3to0.30mg/L, the standard curve equation is y=14015х+408.67(R2is0.9915), and the estimated limit of detection(LOD) is1.94х10-3mg/L. The relative standard deviation is5.41%(n=7) at a level of0.10mg/L. The sensitivity of2-naphthol detection increased at least20times compared to conventional liquid fluorescence detection and100times compared to the reported method of RP-HPLCFinally, according to the SEM images and the comparison of2-naphthalene sulfonic acid enriched on different material membranes and different pore sizes of nylon membranes, it is found that the analyte can be retained on the nylon membrane because of the interaction of the chemical reactions and the physical effects.