FIG. 8A is a schematic drawing showing a front view of the second example of an adaptor 107 a (also referred to as a piece of capillary tube or a capillary tube); FIG. 8B is a schematic drawing showing a top view of the adaptor shown in FIG. 8A; FIG. 8C is a cross-sectional view through the adaptor shown in FIG. 8A along line C-C; and FIG. 8D is a perspective view of the adaptor shown in FIG. 8A.