The question refers to using an electric arc to excite the sample. Obviously the choice of electrode will add to the spectra... Has anyone here tried using an arc? I figure DC would move material from one electrode to the other, adding more electrode material into the arc and contaminating or swamping the sample emission. AC arc seems like a logical choice, the second part to this question is what choice of material to use for the electrode to minimise peaks? Considering carbon rods, Tungsten welding TIG rods, any advice on this would be helpful.
The reason for joining this community came about from a friend asking about a cheap way to test for Lead contamination in cheap Knock Off toys. Spectrometry seemed like a good choice and the USB webcam Spectro' was a quick easy fun build that shows plenty of promise. With the sample being plastic and the target/sample emission spectra being Lead the obvious considerations are will the Lead be hidden by the emission from the electrode, and can an arc be easily setup so others may take advantage of this method. I have some ignition coil drivers that could serve as the High Voltage source, that just leaves choice of electrode.