Classification of graphite tubes
1, according to the heating way: longitudinally heated graphite tube, transverse heating graphite tube
2, according to the performance: ordinary graphite tube (non thermal) for low temperature (less than or equal to 2000 DEG C) of atomic elements such as silver, cadmium and lead; pyrolytic graphite tubes for low, medium and high temperature (>2500 DEG C) atomic elements; suitable for middle and low temperature platform graphite tube (less than or equal to 2400 DEG C) atomization element.
The function of graphite tube
Atomic absorption spectrometry is according to the measured element in a gaseous atom has strong absorption effect and the establishment of the elements of the atomic resonance radiation. This method has the advantages of low detection limit, high accuracy, good selectivity, fast analysis and so on.
Absorption path in the temperature conditions, fixed sampling experiments, the samples generated by the measured elements of the atomic radiation by hollow cathode lamp as the light source of the sharp line elements produce monochromatic light absorption, the absorbance (A) and the concentration of the element in the sample (C) than Cheng Zheng. That is, A=KC type, K is constant. Accordingly, by measuring the absorbance of standard solution and the unknown solution, also known as the concentration of standard solution, standard curve to determine unknown liquid analyte concentration.
The method is applicable to the analysis of trace and trace elements in the samples.