Digestion device preheating:Turn on the power of the digester, select the total phosphorus digestion mode (125°C, 30min), press confirm (or start), and the digester will automatically heat up and preheat;
Concentration prediction:Before testing the water sample, the total phosphorus value of the water sample is predicted, and the operation steps corresponding to the range are selected, e.g., the total phosphorus concentration value is predicted to be 0-Between 2mg/L, you need to choose the operation step of 0-2mg/L range; If the total phosphorus concentration is predicted to be 2-20mg/L, the 2-20mg/L range is selectedSudden.
1. When the predicted value is in the range of 0 -2 mg/L
If total phosphorus is present, the water sample will show blue, and the darker the water sample, the higher the concentration value. Analytical Procedure: Total phosphorus L; Watch out for overrange tips!
2. When the predicted value is in the range of 2-20mg/L
If total phosphorus is present, the water sample will show blue, and the darker the water sample, the higher the concentration value. Analytical procedure: total phosphorus H; Watch out for overrange tips!
3. When the predicted value exceeds 20 mgL /L
The water sample needs to be diluted to the corresponding concentration value in sections 1-2 above, and then operated according to the corresponding range, and the determination result is multiplied by the dilution factor.
4. Test steps on the computer
5. Precautions
◆ If there is total phosphorus, the water sample is shown blue, and the darker the color, the higher the concentration value of the water sample.
◆ Pay attention to cross-contamination, use different measuring utensils for different liquids (pay attention to changing the tip when using a pipette).
◆ Use a suitable pipette to take the liquid, do not use a 5mL pipette to remove 2mL and less liquid, less than or equal to 2mL of liquid, it is recommendedPipette 2 times with a 1mL pipette.
◆ When using a pipette, it is necessary to calibrate the pipette frequently (it is recommended to do so once a week), and pay attention to replacing the tip during use.
◆ The protective cover must be covered during the heating and digestion process of the digester. During the digestion process, beware of scalding, pay attention to the high temperature area of the digester.
◆ After the digestion tube is taken out from the digester, take one piece at a time, it is forbidden to take out multiple tubes at the same time, pay attention to the high temperature, and prohibit shaking.
◆ The cooling process can be natural cooling or water cooling, but the temperature must be below 100°C to be water-cooled.
◆ The digested water sample must be completely cooled before proceeding to the next step.
◆ The digested sample tube must be clear and translucent (colored, but must not be turbid and free of suspended solids)
6 6. Interfering substances
