The very first spectrum in this thread should be treated with caution. By that I mean a lot of the features are artifacts caused by the interline nature of the camera and very poor dispersion aspect. The others were captured with much better dispersion aspect and are pretty much genuine.
With the reference libraries that are available it is possible to have a good stab at most of the lines. There are surprisingly few elements involved. Due the electronic configuration unsurprisingly the majority are Fe. There are just a huge number if Fe multiplets from the UV right through to the green/red end.
Most pro observers only use Mg, Na and the series of Fe multiplets around the Mg line. As these are the most common and strongest lines the ratio’s can be used to construct ternary diagrams that can reveal quite a lot about any given meteor and the comparison to others. However due to the inherent lack of inital condition knowledge the method needs quite a lot of care