1. A method for the spectral analysis of samples in a graphite tube, said graphite tube having a temperature, comprising the steps of: (a) inserting a liquid sample into a graphite tube having an interior; (b) drying said sample by heating said graphite tube; (c) transferring said sample into a particle cloud by further heating up said graphite tube thereby generating optical signals or providing optical signals influencing conditions in said particle cloud; and (d) measuring one of said optical signals influenced or generated by said sample in said particle cloud with a detector; wherein (e) image sequences of images of said interior of said graphite tube are recorded with a two-dimensional camera having a plurality of image elements over selected periods of time for spectral analysis, wherein the optical path of the camera does not influence the optical path of said optical signals measured with said detector; (f) said images of said image sequences are automatically processed with image processing methods; (g) a reference image of said interior of said graphite tube is determined; (h) the condition of said graphite tube, of said sample and/or of a dosing means for the inserting said sample into said graphite tube is determined by comparison of said images of said image sequences to said reference image; and (i) wherein said temperature of said graphite tube is controlled depending on said condition or depending on parameters which describe said condition.