比光谱导数法同时测定食品中苯甲酸和糖精钠的含量

苯甲酸和糖精钠的吸收光谱重叠严重 ,本文建立了用比光谱导数法同时测定食品中两者含量的方法。结果表明 ,在不需要进行分离和掩蔽的条件下 ,可直接测定苯甲酸和糖精钠的含量 ,采用 2 4 5nm和 2 55nm分别作为两者的测量波长 ,其浓度分别在 0～ 90 μg/mL和0～ 10 0 μg/mL之内符合线性关系 ,回归的相关系数r均达 0 999以上。 5种食品中的苯甲酸和糖精钠含量测定的回收率分别为 97 7%～ 10 0 2 %和 10 1 2 %～ 10 4 4 % ,精密度 (测定 5次 )分别为 0 8%～ 4 9%和 0 9%～ 3 7%。此外 ,本文还讨论了波长、共存物、求导间隔等影响测定的因素 ,优化了测量条件。

Determination of Benzoic Acid and Sodium Saccharin in Food by Derivative Ratio Spectrum Method

Spectrums of benzoic acid and sodium saccharin are overlapped seriously in solution The method of determining their concentration in food by derivative ratio spectrum is proposed The linearity of benzoic acid and sodium saccharinis in the ranges from 0 to 90?μg/ml and 0 to 100?μg/ml,respectively, and the correlative coefficients“r” are all above 0 999 when their determining wave length is 245?nm and 255?nm,respectively The results of five kinds of food testes are as following:the recoveries of benzoic acid and sodium saccharin range from 97 7% to 100 2% and from 101 2% to 104 4%,respectively;their RSD(5 times) are less than 4 9% and 3 7%,respectively In addition, The influential factors,such as wavelength,concomitant,and the derivative interval etc are discussed, the determining conditions are optimized