| Abstract: | ABSTRACT A series piezoelectric quartz crystal (SPQC) sensor has been applied to detect L-glutamic acid and L-lysine acid. The effect of formaldehyde solution on the frequency shift was studied. Two methods were discussed. For the calibration curve method, in a neutralized formaldehyde medium, the linear ranges for determining L-glutamic acid and L-lysine acid were from 7.1×10?6M to 6.5×10?4M and from 6.9×10?6 M to 7.4×10?4 M, respectively, with the detection limit being 7.1×10?6 M and 6.9×10?6 M, the recoveries were 99.2% and 100.1%, the R.S.D were 1.63% (n=6) and 1.83%(n=6), respectively. Frequencimetric tiration method was also described and the lowest titratable concentrations were 8.3×10?5M and 5.5×10?5 M, respectively. |
