杜马斯燃烧法测定食品中总氮含量

以各类食品为试验材料,分析了各种参数对杜马斯燃烧法测定含氮量结果的影响,并比对了杜马斯法和凯氏法的测定结果。结果表明,当通氧量为110~200 mL/min,反应炉温度设定900℃以上,样品量在100~150 mg时,测定结果理想。大部分食品样品杜马斯和凯氏法无显著性差别。但杜马斯法结果RSD较凯氏法稍大。另改进前处理方法,杜马斯法还可以用于测定液体食品中的氮含量,结果准确。

Determination of Nitrogen Content in Foodstuffs by Dumas Combustion Method

This study was conducted to evaluate the effect of different parameter on the result of nitrogen content determinited by Dumas combustion method,based on the different kind of foodstuffs.The results showed that the satisfied result was obstained when the flow of O2 was 110~200 mL/min,furnace temperature was above 900 ℃,and the sample mass was between 100-150mg.To most of foodstuffs,there was no significent difference on the Dumas combustion method and Kjeldahl method,expect the RSD was higher by Dumas method.And exect result was obstined on liqid foodstuffs by Dumas method,by improved dealing method.