Figures of the Article

• Statistical results of the relationship between alkaline potassium persulfate solution and blank absorbance at different storage times.
• Comparative schematic diagram of the structure of digestion fixed equipment using binding method and insertion method.
• Statistics of total nitrogen content determination results for three typical water quality samples at different digestion times.
• Statistics of total nitrogen determination results in comparative experiments of water quality samples under acidified and non acidified conditions for different storage times.