Semimicro apparatus centrifuge tube

Semicarbazide hydrochloride, 954 Semicarbazones, 333, 342. 344, 1075 Semimicro apparatus centrifuge tube, 1101 damp, 1104... 

The scale of the recrystallisation envisaged in group (1) means that the operations are carried out in the conventional manner but in apparatus of reduced size. Thus small conical flasks (5 to 20 ml), pear-shaped flasks (5 to 20 ml), semimicro test tubes (75 x 10mm or 100 x 12mm) or centrifuge tubes (1 to 5ml)... 

A more elaborate arrangement which will, however, meet the requirements of several workers, is Barber s water bath rack (Fig. 2.23). The dimensions of a rack of smaller size are given in Fig. 2.24, This rack will accommodate four centrifuge tubes and four semimicro test-tubes. The apparatus is constructed of monel metal, stainless steel, a plastic material which is unaffected by water at 100°C, or of brass which is subsequently tinned. The brass may be tinned by boiling with 20% sodium hydroxide solution containing a few lumps of metallic tin. 

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