An improved method for the determination of carbonate content in soil by air volume method
In order to simplify the process of determination of carbonate content in soil,this study proposes an improved gas volume method device for batch determination of carbonate content in soil.In this method,the soil sample was placed in a conical flask with a stirrer,and the entire degassing device was vacuumized to-0.1 MPa by a vacuum pump,and the vacuum was continued for 3 min.Then,10 mL of hydrochloric acid solution was slowly added and the stirrer was started.The carbon dioxide released by the reaction of carbon-ate and hydrochloric acid in the sample enters the upper end of the detaching pipe through the detaching pipe containing water.When the water column in the detaching pipe does not change,the water is injected into the reaction bottle and the detaching pipe through the upper pipe of the reaction bottle,and the carbon diox-ide gas is driven to the upper end of the detaching pipe.The gas volume is extracted and recorded by a syr-inge,and the recorded volume is converted into calcium carbonate content.The method was applied to the determination of national standard materials and actual samples,and the accuracy was verified by recovery experiments.The results showed that the relative standard deviation was 1.42％to 4.46％,the recovery rate was 97.3％to 101.0％,and the determination results of national standard materials were within the uncertainty range of the identified values,indicating that the method had high accuracy and good reproduc-ibility.In addition,the method is simple and fast,and the analysis efficiency is high,which is suitable for the determination of carbonate content in soil.
gas volume methodcarbonatesdegassing devicevacuuming
万方数据
维普
