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Application and Microwave Characteristics of High-throughput Airtight Microwave Digestion Apparatus
The microwave digestion instrument can perform rapid and efficient digestion and determination of chemical oxygen demand (CODcr), total phosphorus (TP), and total nitrogen (TN) in various surface water, domestic sewage, and industrial wastewater. It is widely used in the identification and management of water quality by environmental protection departments at all levels, water resources management departments and public health departments.
Microwave organic synthesis will replace traditional synthesis methods with its application advantages. Sample preparation for analytical instruments such as atomic absorption spectrometer, atomic fluorescence spectrometer, inductively coupled plasma emission spectrometer, inductively coupled plasma mass spectrometer, high performance liquid chromatography, gas chromatograph, etc. More and more laboratories have adopted microwave sample processing systems to replace time-consuming, labor-intensive, and polluting methods.
Characteristics of high-throughput closed microwave digestion apparatus microwave:
1. Metal materials do not absorb microwaves, but only reflect microwaves. Such as copper, iron, aluminum and so on. Use metal (stainless steel plate) as the hearth of the microwave oven, and the back and forth reflection acts on the heating material. Metal containers cannot be used in microwave ovens, as reflected microwaves can damage the magnetron.
2. An insulator can transmit microwaves, and it hardly absorbs the energy of microwaves. Such as glass, ceramics, plastics (polyethylene, polystyrene), teflon, quartz, paper, etc., they are transparent to microwaves, and microwaves can penetrate them to propagate forward. None of these substances absorb microwave energy, or absorb very little microwaves. The strength of a substance to absorb microwaves is essentially related to the complex permittivity of the substance, that is, the greater the loss factor, the stronger the ability to absorb microwaves. Most household microwave containers are plastic products. The materials used in the microwave airtight digestion and dissolving tank are polytetrafluoroethylene, engineering plastics, etc.
3. Substances with polar molecules will absorb microwaves (substances with a large loss factor), such as water, acid, etc. Their molecules have a dipole moment (that is, the centers of the positive and negative charges of the molecules do not coincide. The polar molecules rapidly change their orientations in the microwave field with the frequency of the microwaves, and rotate back and forth, causing the molecules to collide and rub with each other, absorbing the microwave's The energy increases the temperature. The food we eat contains water, and water is a strong polar molecule, so it can be heated in a microwave oven.
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