A
vacuum desiccator with a porcelain plate was used to form a closed system in which tobacco cuts and added nitrate and nitrite could be separated during storage.
After molding, the samples were immediately sealed in a polyethylene bag and placed in a
vacuum desiccator for at least 21 days prior to tensile testing.
Dark green coloured precipitates so obtained were filtered, washed with acetone, and dried over anhydrous calcium chloride in a
vacuum desiccator at room temperature.
The purified polyisoprene was dried for 12 hours at room temperature in a
vacuum desiccator, then weighed and dissolved in chloroform at a ratio of 1:1 (w/v).
Solvent was removed from the receiver under reduced pressure by use of a
vacuum desiccator (typically 1 h at room temperature).
The solvent was removed in a
vacuum desiccator or with a stream of air.
n-Galactosyl-[beta]1-1'-ceramide (C8:0; [beta]-Gal-[C.sub.8]-Cer; Avanti) substrate stock solution (200 [micro]L of 3 mmol/L solution in methanol) and ceramide (C10:0; [C.sub.10]-Cer; Avanti) internal standard stock solution (240 [micro]L of 0.05 mmol/L solution in methanol) were added to a 5-mL glass vial, and the solvent was removed in a
vacuum desiccator. We then added 240 [micro]L of an aqueous solution of sodium taurocholate (120 g/L) and oleic acid (12 g/L) to the vial, vortex-mixed the sample until the residue dissolved, and then added 2.76 mL of citrate-phosphate buffer, pH 4.5 (0.2 mol/L [Na.sub.2]HP[O.sub.4], 0.1 mol/L sodium citrate; pH adjusted with 6 mol/L HCI).
The residue was dried in a
vacuum desiccator over [P.sub.2][O.sub.5]-KOH.