Autoclave indicators

Sterile products (large volume liquids > 100 ml, autoclaved) Indication, use... 

On a laboratory scale, hydrotliennal syntliesis is usually carried out in Teflon-coated, stainless-steel autoclaves under autogenous pressure. A typical syntliesis mixture consists of up to four major constituents, a T-atoni source (silicon and aluminium, otlier elements may also be incoriiorated as indicated above), a solvent (almost exclusively... 

Indicators can be utilized to distinguish packages that have been processed from those that have not been processed. These are external indicators that do not have the capabiUty to detect critical shortcomings in cycle parameters because they are not located inside the packages. A weU-known example of this type is autoclave tape, which is also used to hold together packages wrapped in muslin or other kinds of wrap-type packaging materials (qv). 

There are problems to be considered and avoided when using Hquid-in-glass thermometers. One type of these is pressure errors. The change in height of the mercury column is a function of the volume of the bulb compared to the volume of the capillary. An external pressure (positive or negative) which tends to alter the bulb volume causes an error of indication, which may be small for normal barometric pressure variations but large when, for example, using the thermometer in an autoclave or pressure vessel. 

In many commercial brochures, chemical resistance is indicated as excellent, good, fair, or poor. Although the test method is usually outlined, wide interpretation is possible. Immersion tests are usually described in this manner. Hydrolytic stabiUty is tested by salt-spray cycling or autoclave cycling. 

A) Preparation of 1-Methyl-2-Picolinium Chloride 98 ml of cx-picoline is dissolved in 200 ml of methanol, cooled and 85 ml (at -68°C) of methyl chloride is added. The solution is charged to an autoclave, sealed and the nitrogen pressure of 300 psig is established. The mixture is heated at 120° to 130°C for 2 hours, cooled and opened. The resulting solution is then evaporated to dryness in vacuo, yielding a residue of 110 g. This residue is then dissolved in 50 ml of water and extracted with two 50 ml portions of ether. The aqueous phase is then diluted to 150 ml with water and an assay for ionic chloride is performed which indicates the presence of chloride ion equivalent to 721 mg/ml of 1-methyl-2-picolinium chloride. 

Above about 600°C penetration of oxygen and nitrogen occurs. It has already been indicated that the presence of these elements renders the titanium brittle, and this feature must be taken into account in considering the use of titanium at elevated temperatures. Titanium has nevertheless been successfully employed as an autoclave lining in steam atmospheres at a temperature of 400°C and a pressure of lOMPa. 

A red solution of 0.1 to 0.2 mmol of ( + )-(.9)-l2 (R = CH3) in 5 mL of toluene and an ampule with an 0.3-1.2 mmol amount of BF, are placed into an autoclave, which has been flushed with CO as described above. When the CO pressure is increased to 3.0 xlO5 Torr, the ampule bursts. After 16 h at r.t., the concentrated yellow solution is chromatographed. F.lution with toluene indicates that there is no remaining starting material. Elution with (C2H5)0 yields the desired (-)-(/()-13 yield 44-55% op 92% (determined by measurement of the optical rotation). 

Example 5. Glycolysis of Polyurethanes with Propylene Oxide after Pretreatment with Ethanolamine.55 A rigid polyurethane foam (ca. 100 g) was dissolved in 30 g ethanolamine by heating. Excess ethanolamine was stripped, leaving a clear solution. Infrared and GPC analysis indicated that the clear solution obtained contained some residual polyurethane, aromatic polyurea, aliphatic polyols, aromatic amines, and N,N -bis(f -hydroxyethyljurea. Next the mixture was dissolved in 45 g propylene oxide and heated at 120°C in an autoclave for 2 h. The pressure increased to 40 psi and then fell to 30 psi at the end of the 2-h heating period. The product was a brown oil with a hydroxyl number of485. 

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