Comparison of the Chinese Pharmacopoeia method and abroad pharmacopoeia methods in determining total nitrogen content of dextran 40

Objective To compare the methods for determining the total nitrogen content of dextran 40 raw materials in Chinese Pharmacopoeia and abroad pharmacopoeia.Method The nitrogen content in 11 batch dextran 40 raw materials were analyzed by using the methods of Chinese Pharmacopoeia(2010 version),the United States Pharmacopoeia(USP-32),the Japanese Pharmacopoeia(JP Ⅹ Ⅴ),British Pharmacopoeia(BP 2010) and European Pharmacopoeia(EP 6.0),respectively.Results The results showed that the Nessler's colorimetric method of Chinese Pharmacopoeia and the Kjeldahl method of foreign pharmacopoeia were consistent.Conclusion The Nessler's colorimetric method is easy and simple as a limit test,and has some practical value.The Kjeldahl method is more complicated,but the quantitative results are accurate.