Baking glassware

Silylation of apparatus makes it repellant to water and hydrophilic materials. It minimises loss of solute by adsorption onto the walls of the container. The glassware is placed in a desiccator containing dichloromethyl silane (ImL) in a small beaker and evacuated for 5min. The vacuum is turned off and air is introduced into the desiccator which allows the silylating agent to coat the glassware uniformly. The desiccator is then evacuated, closed and set aside for 2h. The glassware is removed from the desiccator and baked at 180° for 2h before use. 

Note all reusable glassware (except volumetric pipettes) should be baked in a mufAe oven at 450 °C for at least 2 h to remove possible contamination before use. 

All glassware, syringes and flex-needles were baked in an oven at 120°C overnight and assembled while hot. 

What had happened to this sample to yield such unexpected results The purity of the starting monomer, other than its water content, was probably no better or worse than that used in previous studies. The final degassing of the monomer had been conventional. Only one difference had been introduced in the preparative scheme—the monomer had been dried over baked silica gel, and the glassware of the vacuum apparatus had been flame-dried under vacuum. In other words, the irradiated styrene had been exhaustively dried. 

After bake-out, the glassware is allowed to cool to room temperature. Breakseal 2 is broken, and monomer in A is degassed by successive freeze-pump-thaw cycles. The thoroughly degassed monomer is then distilled onto the silica gel in B by surrounding that vessel with an ice-water bath. When sufficient monomer has been transferred, the contents of A and B are frozen, and A is removed from the manifold by flame sealing. 

Resin Elution Concentration. The first three ethyl ether elutions were combined into a 500-mL glass bottle with a Teflon cap liner. The bottles and all the laboratory glassware used in the sample analysis were cleaned with 6.0 N HC1, acetone, and hexane and then baked at 200 °C to remove the solvent. The combined elutions were brought to the laboratory for evaporative concentration and analysis. 

Do not bake reusable glassware as a routine part of cleaning. Baking may be warranted after particularly dirty samples are encountered, but should be minimized, as repeated baking may cause active sites on the glass surface that will irreversibly adsorb PCDDs/PCDFs. 

Glassware should be baked overnight at 200°C. Nondisposable plasticware should be rinsed thoroughly with 0.1 A NaOH, 1 mill ethylenediamine-tetra-acetic acid (EDTA), and then with RNase-free (diethylpyrocarbonate [DEPC]-treated) water. Alternatively, it can be treated with RNase AWAY (Molecular BioProducts), according to the manufacturer s instructions. 

It is a sine qua non to avoid any contamination with RNases. Sterile, disposable plasticware is essentially RNase-free and should be used whenever possible. General laboratory glassware, however, should be treated by baking at 180°C overnight, or, in the case of... 

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