Abstract: [Objective]The national standard method of sodium carboxymethyl cellulose is time-consuming and inefficient,so it is necessary to find a simple,rapid and accurate method.[Method]By comparing the detection process and data of acidimeter method,conductivity method,atomic absorption flame spectrometry and ashing method,to identify the method that has advantages over ashing method among the three methods.[Result]Using acidimeter method to detect different types of carboxymethyl cellulose sodium,the sample size is uncertain.Conductivity method has no obvious inflection point and the end point is not clear.The relative standard deviation of atomic absorption flame spectrometry is 0.74%,and no significant difference compared with ashing method.[Conclusion]Through comparison,acidimeter method and ashing method have limitations.The atomic absorption flame spectrometry has the advantages of good stability,high accuracy and high detection efficiency,which can be used in daily inspection.

Key words: degree of substitution, atomic absorption flame spectrometry, acidimeter method, conductivity method, standard curve, method comparison