Spectrometer sampling chamber structures are disclosed which avoid purge loss during loading and unloading of samples. In two disclosed versions, a plunger carries the sample, and fits closely inside a fixed tube, into which it is inserted for sample illumination. Sample loading and unloading is accomplished without fully removing the plunger from the tube. Also, an automatic purging flow of gas from the interior of the spectrometer is caused during insertion of a new sample. In a third disclosed version, vertically stacked sample holders move through a vertical chute into which they are inserted to the top of the sample chamber, and from which they are removed at the bottom of the sample chamber.