Glove box system

Fig. 1. Double glove-box system for the preparation and refining of actinide metals 1. RF heating system 2. Water cooled quartz vacuum furnace 3. Box filled with circulating nitrogen 4. -I- 5. Argon in and out filters filter 6. Stainless steel box filled with circulating argon 7. Vacuum lock chamber 8. Pump...

In the case of BIS, monoenergetic electrons from an electron gun impinge on the sample the reponse to be analysed is constituted of photons. No heavy and sophisticated electron energy analyser is necessary. Therefore, protection against radioactive hazards can be easily achieved by inserting the complete spectrometer into a glove box system. 

In this section some glove box systems will be discussed with comments which will put them into perspective for potential applications. 

Figure 4 The M. Brown Lab master 130 glove box system. A typical example of state-of-the-art glove boxes that include a microprocessor control unit that monitors the pressure, H20 and 02 contamination level and the circulation/regeneration life cycle of the H20 and 02 absorbers.

In the usual glove box equipped with only H20 and 02 absorbers, the concentration of C02 and N2 may increase during normal operation with no control. Both gases are electroactive, particularly on active metal and noble metal electrodes polarized to low potentials. When elimination of N2 is required (e.g., in the case of spectroscopic studies of active metal electrodes), the glove box system has to include a commercial N2 absorber. Companies such as VAC pro-... 

In general, four types of cabinets are used for work with research quantities of chemical carcinogens. These are the conventional fume hood a Class I biological safety cabinet a Class II (Type B) biological safety cabinet and a Class III closed glove box system (8). 

The facility must be designed to control access. Signs should designate restricted areas. Clothing requirements for entry should be identified. There should be directional air control with adequate ventilation rates. Primary containment equipment such as chemical fume hoods, a Class I or Class II (Type B) biological safety cabinet, or a glove box system should be available for use with known or suspect chemical carcinogens or other toxic substances. 

FIGURE 2-2 Glove-box system in the operations trailer of the RRS. SOURCE U.S. Army (2001c). 

The Ca metal reductant is purchased commercially as triply distilled metal and is further purified by distillation under a partial pressure of 6Torr (8x 10 Pa) of He. The Ca as prepared contains less than 10 ppm by wt. O. However, when Ca is exposed to the air it quickly picks up oxygen - probably as adsorbed H2O - and therefore, after purification it is essential that the Ca be handled and stored under an inert atmosphere. To do this the Ca distillate is placed in a He filled glove box, removed from the condenser and placed in Pyrex fruit preserving jars. The lids are tightened and the jars are transported to another glove box system and stored until needed. 

For the purpose of measuring the infrared spectra of unstable species such as free radicals in solution, it is advisable to place a small Fourier transform infrared (FT-IR) spectrometer into an inert-gas glovebox system, in which the concentrations of oxygen and water vapor can be kept at <0.1 ppm. In such an experimental setup, it is possible to generate unstable species in appropriate solvents and measure their infrared spectra in solution [6]. Preferably, a small ultraviolet/visible spectrometer should also be placed within the glove-box system. Then, it will be possible to determine the concentration of the unstable species under study by additionally measuring its ultraviolet/visible absorption spectrum, provided the molar absorption coefficient of the ultraviolet/visible absorption band of the unstable species is known. 

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