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Super Microwave Digestion System

Products Detail
Super Microwave Digestion System
1. How to choose the model and configuration?

(1) EXPEC 786C -high cost performance, can meet most digestion needs of food, environment and other industries; EXPEC 790S -high performance, suitable for customers (enterprises) who have a certain difficulty in digesting samples.
For temperature and pressure requirements, graphite, silicon carbide, plastic, rock and other samples must be digested with EXPEC 790S. Other conventional foods, medicines, and cosmetics can be digested with 786 series.
(2) Only ore, soil, and cosmetics need to be added with HF, and TFM digestion tubes are required; For conventional samples such as food and wastewater, quartz digestion tubes are enough, with high temperature resistant, low cost, and more can be added.
(3) The quartz digestion tube has the purest background (except boron), but it cannot add hydrofluoric acid, and is most suitable for food and medicine; Teflon tubes can use HF, but the price is more expensive than quartz; glass tubes have high background impurities, which can be used as materials, cosmetics, and soil leaching.
(4) For water samples, the standard requires sampling is 25mL, and 6 position-65mL digestion tubes are required.

2. The function and loss of adding nitrogen in advance?

Reply: Before the reaction, 40Bar high-pressure nitrogen gas will be added to avoid cross-contamination and bubbling and boiling. Argon can also be used instead of air. The purity requirement of nitrogen is not high, more than 99.9% is enough. A bottle of 40L nitrogen is used about 100 times. Cylinders are generally leased locally.

3. How long does it take to do a test?

Reply: For environmental samples, the soil/filter membrane takes about 50 minutes, for traditional microwaves, it takes about 60-70 minutes, for water samples, it takes about 20 minutes, and for food samples, it takes about 40 minutes. There will be no significant reduction in the single sample preparation time between super microwave and ordinary microwave. However, super microwave does not require pre-digestion and acid removal, and it will save time for disassembling and assembling equipment.

4. Is pre-digestion required?

Reply: In order to avoid bursting tubes, traditional microwaves require pre-digestion, and substances that are prone to violent reactions are reacted first, but super microwaves do not require.

5. Can perchloric acid be added?

Reply: Sulfuric acid, phosphoric acid, hydrogen peroxide, and perchloric acid can all be added. Generally, no more than 2mL is enough. There is no risk of tube explosion. If you need more, please consult the application engineer.

6. Will there be cross-contamination?

Reply: Before the experiment, it will be filled with 40Bar high-pressure nitrogen to prevent the sample from bubbling and boiling, so there will be no cross-contamination.

7. Is it necessary to remove acid?

Reply: The acid removal is determined by the amount of acid added. Generally about 1h, traditional microwave about 3-4h. If you follow our recommended method, you don't need to removal acid. However, due to the low acidity requirements of the original graphite, it must be removal-acid, about 1-1.5h.

8. What consumables does the super microwave have?

Reply: The rubber rings for sealing - the large ring and the small ring are consumables. The large ring is expected to be used 50 times, and the small ring is used 100 times. A bottle of silicone oil lasts about a year.

9. What is the difference between 790S and 786C?

Reply: In terms of performance, the 790S can reach 300°C, 200Bar, and the 786C can reach 260°C, 120Bar. In terms of hardware, sensors are different, and software/hardware control systems are different. There is not much difference in the use of regular soil, food, and cosmetics. Plastics, ceramics, coal, ores, etc. need to be selected according to the difficulty of the sample.

10. Which samples have advantages in super microwave testing?

(1) Food oils and fats: Digestion of organic matter is easy to generate a large amount of carbon dioxide, nitrogen oxides and other gases, which tests the pressure-bearing performance of the instrument; super microwave does not require pre-digestion, which saves experimental time; and generally high-throughput use increases the temperature difference for a long time, resulting in digestion incomplete.
(2) Plastics: High molecular polymers, the chemical bonds of the polymers can only be broken at ultra-high temperatures, and digestion is easy to produce a large amount of carbon dioxide, nitrogen oxides and other gases, which tests the pressure and temperature rise performance of the instrument;
(3) Pharmaceuticals: The more benzene rings such as chemical drugs (API), the more difficult it is to digest. Ultra-high temperature can break up the chemical bonds of polymers, which is generally difficult to digest with ordinary microwaves; digestion of capsules tends to produce a large amount of carbon dioxide, nitrogen oxides and other gases. High pressure and temperature rise performance, violent reaction and explosive tube.

11. What kind of laboratory conditions are required?

Reply: Nitrogen and argon cylinders are required at the same time, and nitrogen pipelines with centralized gas supply can also be used. The nitrogen pressure is not less than 50Bar. The nitrogen pressure in the gas-liquid phase is generally low, and it is not enough to be configured separately; some customers need to centralize the gas supply, and it is not allowed to be placed next to the equipment, just make a long pipeline.