A hydrolytic procedure giving reproducible analytical conditions

A hydrolytic procedure which can be routinely performed in a readily reproducible environment is described. The procedure is useful in that it can be applied to batches of samples, giving a high degree of confidence that similar conditions exist within and among batches. The method makes use of a special polythene capillary leak plug which is fitted in the mouth of ampoules (which were back-filled with nitrogen) prior to their being sealed in the open laboratory. This plug acts as an efficient barrier, for several minutes, to gaseous diffusion, allowing only small amounts of oxygen to enter the ampoule. The method is demonstrated by results from amino acid analyses of acid-hydrolyzed samples of bovine serum albumin.