High pressure digestion tank - Determination of cadmium, lead, chromium, copper, zinc, and nickel in soil

1、 High pressure digestion tankAlso known as pressure digestion device, pressure digestion tank, sealed high-pressure digestion tank, digestion tank, polytetrafluoroethylene high-pressure tank,Detection of heavy metals such as lead, chromium, cadmium, methylmercury, and inorganic arsenic in rare earths, fruits and vegetables, grains and oils, eggs, meat, etc.

The high-pressure digestion method has been recognized by relevant departments in China as the standard method for detecting selenium elements in rice produced and processed by manufacturers. The pressure digestion tank is used for spot direct sales, such as GB/T5009、GB/T14962、GB/T6609、GB/T11914、GB/T17378、SN/T2004.1、22005、SN/T 1634-2005 Wait. The American AOAC also stipulates that this method is the standard sample decomposition method for determining elements such as As, Cd, Hg, Pb, Se, Zn, etc.

IIHigh pressure digestion tankFeatures:

1. Good sealing: The concave convex tenon groove design of the inner cup of the high-pressure digestion tank, Inner cup lid with pointed bottom design,Convenient for sample collection after the experiment is completed；

2. Safety:There is a vent hole on the top of the cup,Even in the case of temperature runaway, only the inner cup will deform, and the outer can will not break；

• High digestion efficiency, wide adaptability, and the ability to digest many samples that are difficult to digest by traditional methods;
• The low blank value of the inner cup element improves the accuracy and precision of analysis, reduces work intensity and environmental pollution;

We advocate for conducting experiments that are healthy, efficient, safe, and environmentally friendly

• Notes

1. The amount of solvent added for digestion depends on different experiments, generally ranging from 1/3 to 1/5 of the capacity of the inner cup

2. If perchloric acid and hydrogen peroxide are used in the experiment, the amount should not be too much, and cold nitrification treatment should be carried out overnight

3. Just after digestion, due to excessive pressure inside, it was easy to open when cooled to room temperature

4for example：Determination of cadmium, lead, chromium, copper, zinc, and nickel in soil

1. Weigh 0.2g of soil standard sample GBW-07430 (GSS-16), place it in a 50ml PTFE tube, add about 1ml of high-purity water to wet the soil, and shake well.

2. Place the sample tube into the fully automatic graphite digestion instrument, set the digestion program, and run it. Simultaneously create reagent blanks.

After digestion is complete, filter the sample with a fixed volume and wait for testing.

① The acid system consists of 6ml hydrochloric acid, 4ml nitric acid, 1ml perchloric acid, and 8ml;

② Add a reflux cap for digestion, and remove the reflux cap during the acid removal stage;

③ The fixed volume is 25ml;

④ Acid needs to be rushed to near dryness;
Dissolving program:

1) Sample addition: 6ml hydrochloric acid; 2) Sample addition: 4ml nitric acid; 3) Sample addition: 1ml perchloric acid; 4) Sample addition: 8ml; 5) Vibration: 20s; (Cover); 6) Heating: temperature 120 ℃, heating time 20 minutes, holding time 1 hour 30 minutes; 7) Heating: temperature 160 ℃, heating time 20 minutes, holding time 3 hours; 8) Cooling: 5 minutes (remove cover); 9) Heating: temperature 180 ℃, heating time 10 minutes, holding time 30 minutes; 10) Cooling: 5 minutes.

After the acid evaporates to near dryness, it is cooled to a volume of 25ml and filtered through a quantitative filter paper for detection