摘要
自组一套简易凯氏定氮装置,对提高装置气密性方法进行研究,并采用单次单因子法对加入双氧水测定虾壳中氮含量的消化条件进行了研究,通过与国标法进行对比,确定该方法测定虾壳中氮含量的可行性。结果表明,加氢氧化钠的漏斗采用水封能提高蒸馏装置的气密性;最佳消化条件为：虾壳0.2 g,五水硫酸铜0.2 g,硫酸钾0.6 g,浓硫酸8 mL,双氧水4 mL,消化40 min。所测虾壳氮含量为（63.48±0.88）mg/g（P=0.95）,加标回收率在95%~100%。该法准确度与国标法相当,且省时、经济、环保,适用于实验教学、科研和生产实践。
The simple Kjeldahl device was assembled,and whether the tightness of distillation unit could be improved by sealing NaOH filter with water was studied.Then the digestion conditions with H2O2 in nitrogen determination of shrimp shell were studied with ＂one-variable-at-a-time＂ method.The results show that the tightness of distillation unit could be improved by sealing NaOH filter with water.The optimal digestion conditions should be shrimp shell 0.2 g,CuSO4·5H2O 0.2 g,K2SO4 0.6 g,H2SO4 8 mL,H2O2 4 mL and digesting for 40 min.The nitrogen in shrimp shell is（63.48±0.88）mg/g under 95% confidence degree.The recovery of standard addition experiments is between 95 and 100%.This method had the same accuracy with national standard.Being time-saving,economic and environmental-friendly,it is suitable to undergraduate experimental teaching,scientific research and production practice.
出处
《实验室研究与探索》
CAS
北大核心
2011年第6期37-39,共3页
Research and Exploration In Laboratory
基金
山东省高等学校教学改革研究项目(2009297)
青岛农业大学实验技术研究项目(SYJK09-20)
关键词
凯氏定氮法
过氧化氢溶液
虾壳
消化条件
kjeldahl nitrogen determination
hydrogen peroxide solution
shrimp shell
digestion conditions
