Equipment cleaning drying

Place 50 g. of o-chloronitrobenzene and 75 g. of clean dry sand in a 250 ml. flask equipped with a mechanical stirrer. Heat the mixture in an oil or fusible metal bath to 215-225° and add, during 40 minutes, 50 g. of copper bronze or, better, of activated copper bronze (Section 11,50, 4) (1), Maintain the temperature at 215-225° for a further 90 minutes and stir continuously. Pour the hot mixture into a Pyrex beaker containing 125 g. of sand and stir until small lumps are formed if the reaction mixture is allowed to cool in the flask, it will set to a hard mass, which can only be removed by breaking the flask. Break up the small lumps by powdering in a mortar, and boil them for 10 minutes with two 400 ml. 

Place 65 g. of clean dry zinc wool and a few crystals of iodine in a 2 5 htre three-necked flask, equipped with an efficient reflux condenser with drying tube, a mechanical stirrer, and a dropping funnel. Prepare a mixture... 

All respiratory protective systems should be stored in clean, dry conditions but be readily accessible. They should be inspected and cleaned regularly, with particular attention to facepiece seals, nonreturn valves, harnesses etc. Issue on a personal basis is essential for regular use otherwise the equipment should be returned to a central position. Records are required of location, date of issue, estimated duration of use of canisters etc. 

However the acid is prepared, the sodium salt may be prepared as described in U.S. Patent 3,503,967 Five liters of methylene chloride were added to a clean dry vessel equipped with stirrer. 7-[a(4-pyridylthio)acetamido] cephalosporanic acid (1,000 g) was added to the vessel, followed by 350 ml of triethylamine. The resultant solution was treated with decolorizing charcoal for 15 minutes and filtered. A solution of sodium-3-ethyl-hexanoate (27.3%) in butanol-methylene chloride was added to the filtrate with stirring. Seven thousand five hundred milliliters of acetone was added. Crystallization occurred while stirring was continued several hours under dry conditions. The crystals were collected by filtration, washed with large volumes of acetone, and then dried in vacuo at 50°C to yield about 950 g of the title compound. 

In a clean, dry crucible, mass out approximately 1 g of lithium chloride, LiCl, another typical ionic compound. (The melting point of sodium chloride, NaCl, is too high to observe using classroom laboratory equipment.)... 

PARTICULATE Organic Residual resist Contaminated cleaning reagents or adhesion promoters. Dirty spin coating equipment or drying ovens. Human debris such as dandruff, hair, etc. 

Three dosages of sample must be estimated to determine the iodine number. Weigh the three dosages (M) of dry carbon to the nearest milligram. Transfer each to one of three clean, dry 250-mL Erlenmeyer flasks equipped with ground glass stoppers. 

Thin slices of tissue are placed in clean plastic petri dishes, the loose fitting lids replaced and the dishes inserted into the chamber of the freeze drier. Blood specimens can be poured directly into the dish. It is important that the tissue be thoroughly frozen prior to evacuating the chamber. The time required for complete drying of the sample depends on the nature and weight of the material and the type of equipment employed. Drying is usually completed in 12—48h. The dried tissue is not susceptible to decay and can be stored at room temperature in sealed plastic bags. 

Time between Completion of Manufacturing and Initiation of Cleaning The time that may elapse from completion of a manufacturing operation to initiation of equipment cleaning should also be stated where excessive delay may affect the adequacy of the established cleaning procedure. For example, residual product may dry and become more difficult to clean [20],... 

Use clean, dry, thin-walled rubber tubing and special adapters with ground-glass joints to connect the tubing to your reaction flask or to the inlet pipe of a bubbler . Where a single cylinder supplies several outlets, e.g. in a fume cupboard, the gas flow rate may change markedly when someone turns off one of the outlets, resulting in an increase in gas pressure to your equipment. You should, therefore, fit a gas blow-off valve between your gas supply and... 

---