As the core of graphite furnace, graphite tube plays a crucial role in achieving overall stability of a certain analysis.
Mainly divided into the following categories:
1. Generally high-density graphite tubes
2. Thermal decomposition coated graphite tube
3. Graphite tubes with L'VOV pathway, and the newly introduced Ω pathway is also being imported now.
4. Horizontal heating of graphite tubes, long-life tubes, etc
Below are several common characteristics of graphite tubes to discuss in detail the selection of graphite tubes for different applications during the analysis process:
High density graphite tube: suitable for the determination of volatile oxides with low atomization temperature, such as Li, Na, K, Rb, Cs, Ag, Au, Be, Mg, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Se, Te, etc. Advantages of application: Strong atmosphere recovery, less likely to generate volatile oxides, therefore better sensitivity than coatings. Especially regarding: Ai, Si, Ge, Sn.
Thermal decomposition coating tube: The primary focus is on the determination of easily constituting carbide elements such as Ca, Cr, Cu, Ba, Sr, Ti, V, Ni, Pt, Rh, Pd, Pt, Ir, especially Ni, Cu, Ca, Ti, Sr. The sensitivity of these elements is 10-30 times higher than that of general high-density graphite tubes.
Path through graphite tube: It primarily relies on the radiation heating of graphite tube, optimizing the atomization isothermal zone, resulting in a significant roughness in the sensitivity and stability performance of analysis.
There are also horizontally heated graphite tubes and long-life graphite tubes, among which long-life graphite tubes can have a much higher lifespan than general graphite tubes under higher temperature conditions (2800 ℃).