UV Spectrophotometry for Simultaneous Determination of Vanillin and Salicylaldehyde in Food

UV absorption characteristics o f vanillin and salicylaldehyde were investigated. Based upon the investigation, a analysis method for the simultaneous determination of vanillin and salicylaldehyde by UV Spectrophotometry was established,Experimental results showed that both vanillin and salicylaldehyde have an iso-absorptive point at 328 nm in the UV absorption spectra, In the present method, the wavelengths of 279 nm and 328 nm were chosen as the wavelengths o f determination of vanillin and salicylaldehyde respectively, and linear relationships between values o f absorbance and concentration were found by the folloing simultaneous equations which were based on their regression equations: Cvan.=(A279-0.028 8)/0.064 5; Csal.=[(A328 nm+0.010 5)/0.029 0]-Cvan., the linearity range was kept between 3 mg/L-30 mg/L, 2 mg/L-20 mg/L for the vanillin and salicylaldehyde respectively, The detection limits were 2,1 mg/L,both standard deviation is less than 2.0 %.The method was successfully applied to the analysis of food samples with satisfied results.Recovery of vanillin and salicylaldehyde achieves 97.3 %-101.1 %.