AIM: To establish equal proportion twice mixing method and make the mixing rationalized. METHODS: Advance basic configuration about the mixing method was brought forward and then studied on the mixing method by means of mathematics illation and experiment validated. RESULTS: The mixing method has been established and proved effective by experiment. CONCLUSION: The mixing method is a special mixing way that is reasonable and economy that can be used in industrial scale.

AIM: We establish a suitable distinguishing reaction of nitrate and nitrite in Chinese traditional medicine containing reduction agents. METHODS: In different concentration solution of sulfate acid,we study on the distinguishing reaction,by paralleling samples with negative samples and positive samples. RESULTS:The nitrite and sample containing nitrite react with ferrous sulfate reagent from brown in 50%-5% solution of sulfate acid;The nitrate and sample containing nitrate react with ferrous sulfate reagent from brown in ≥25% solution of sulfate acid.The negative sample and sample without nitrite and nitrate does not react with ferrous sulfate reagent in 50%-5% solution of sulfate acid. CONCLUSION: The thin sulfate acid-ferrous sulfate reagent-nitrate ditinguishing reaction can be used to distinguish nitrate and nitrite in Chinese traditional medicine containing reduction agents.