Operation procedures. For graphite furnace atomizer is a kind of atomic absorption spectrometry, most of the analyzing conditions are the same, here only illustrate the differences for reference. When graphite furnace atomic absorption spectrometry is selected in the parameters setting interface (Fig. 6-1), the heating program setting box will be shown in the right. Set the heating temperature, duration time, and internal gas flow according to the setting principles and methods that described in “Heating program setting”. Then, fix up the graphite tube and click “OK”, the instrument will do self-checking automatically and display the parameters setting interface (Fig. 6-1). Click “OK” again and switch to the wavelength scanning interface (Fig. 3-7) when all the requirements are met. However, this interface is without the “Ignition” button. Other operations are like the flame method. Click “Next” and switch to the standard sample setting interface. Compared to the flame method, there are several differences. The first difference is that there are three kinds of cooling time for chosen, 15s, 30s, and 45s, with 30s as the default. The second difference is the display mode of the signal, there are three selections (shown in Fig. 6-3) Fig. 6-3
a. Segment display: Display the times and signal waveforms of the whole heating program (drying, ashing, atomization and clear) for each sample.
b. Continuous display: Continuously display the time and signal waveform of atomization for each sample.
c. Overlap display: Display multiple samples in the same graph, and respectively display the time and signal waveform of atomization repeatedly for each sample. Other settings and operations are like the same as the flame method. Click “Blank” and switch to the graphite furnace measurement interface (Fig. 6-4). If a new graphite tube is used, several times of “Null burning” should be done until the absorbance is close to zero. User can click “Test” to check whether the program is run with the settings or not. In the “Single-step set” pane, whether drying, or ashing, or atomization, or clear, once be chosen, and the button “Single-step execution” is clicked, the system will run the single step. Up to 20 times of “Concentrated times” which is used for sample concentration can be set. Either standard sample or sample to be measured, once the concentration procedure is selected, all the concentrated times should be run before measurement. Click “Measure” after adding the sample into the graphite tube, ...
