Nitrogen purifier

Submitters used nitrogen purified by passing it through a set of gas wash bottles containing Fieser s solution, concentrated sulfuric acid, sodium hydroxide, and calcium chloride. 

The submitters used nitrogen purified by passage through B.T.S. catalyst (B.A.S.F., Ludwigshafen, Germany). The checkers used commercial prepurified nitrogen without further treatment. 

The catalytic test of isohexane cracking was carried out by a pulse method. Nitrogen, purified by flowing through MS 13X trap at dry-ice temperature, was used as a carrier gas (20 ml min 1). The catalyst (typically 40 mg) was placed in a quartz tube and pretreated in flowing nitrogen at 873 K. A pulse of isohexane (0.1 pi) was injected into a flow of carrier gas, and the reaction products were analyzed with an on-line gas chromatography equipped with FID. 

The checkers used nitrogen purified by passage through BASF R 3/11 oxygen removal catalyst and molecular sieves. 

Protease-free preparation of CNTs can be obtained using an immobilized-metal-ion affinity chromatography (IMAC) step (Ros-setto et a/., 1992). This procedure is also useful for the purification of He, the 50 kDa carboxy-terminal part of the heavy chain of TeTx, which shows an identical retention time. However, IMAC-chromatography cannot be used for the purification of BoNT/D because this serotype is not retained. To obtain a protease-free BoNT/D preparation, an ion-exchange chromatography procedure was used (Schiavo and Montecucco, 1995). After freezing in liquid nitrogen, purified CNTs are stored at -80°C. 

Caution. Vanadocene, as well as all the vanadium(H) complexes [(F2(/< Cl3)(77ff)6]2[Zn2C/6] and sodium sand, react exothermically with oxygen and water. Therefore, all manipulations should be carried out in a nitrogen-purified atmosphere and in a well-ventilated hood. 

Nitrogen purifying train (see Figure 2.4) for purifying nitrogen supply to... 

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