根据香草醛和水杨醛及其混合物的紫外光谱吸收特性，建立了一种能同时测定香草醛和水杨醛含量的紫外分光光度法。结果表明，香草醛和水杨醛在328 nm波长处有一个等吸收点，选择279 nm和328 nm为测定波长，以其回归方程建立联立方程组，求得了组分浓度与吸光度之间的关系：C 香草醛=（A279-0.0288）/0.0645；C 水杨醛=[（A328nm+0.0105）/0.0290]-C 香草醛。香草醛和水杨醛的线性范围分别为3 mg/L~30 mg/L，2 mg/L~20 mg/L，检出限分别为2、1 mg/L，并对方法的重现性做了实验，上述两种化合物的相对标准偏差均小于2.0%，用于食品中样品的测定，获得较好的分析结果，回收率在97.3%~101.1%之间。%UV absorption characteristics of 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 of determination of vanillin and salicylaldehyde respectively , and linear relationships between values of 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 tothe analysis of food samples with satisfied results.Recovery of vanillin and salicylaldehyde achieves 97.3%-101.1%.
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