- Throat and nose membranes hurt by dry air allow cold viruses to enter more easily. It is important to carry out sensible counter plans against the cold with heaters and against the dryness with humidifiers.
- ‘Repeated exposure may cause skin dryness or cracking’
- Evaporate to dryness, occasionally stirring with a glass rod.
- Evaporate the methanol solution to dryness under reduced pressure at 40 oC by means of a rotary film evaporator (4.3).
- Note 3: If sample extracts are taken to complete dryness at too high temperature sterol losses may occur.
- Evaporate the dichloromethane extract down to dryness on the rotary evaporator (4.2) operating under reduced pressure at 40 oC.
- Evaporate until it had just reached dryness, under reduced pressure at 60 oC by means of the rotary evaporator (4.3).
- Evaporate this fraction until it had just reached dryness by means of the rotary evaporator (4.3) at 60 oC.
- Add one anti-bumping granule and evaporate to near dryness in a waterbath or isomantle, taking care to collect the waste solvents.
- If any silica remains in the residue, redissolve it in a few millilitres of hydrofluoric acid (3.4) and evaporate to dryness.
- Evaporate the solvent nearly to dryness on the rotary evaporator (4.1) with reduced pressure at a bath temperature not exceeding 40 oC.
- Allow to cool, add a few drops of water followed by 10 to 15 ml of hydrofluoric acid (3.4) and evaporate to dryness at about 150 oC.
- Dissolve the residue with about 2 ml of hydrochloric acid (3.1), evaporate to dryness and add 5 ml of 6 mol/litre hydrochloric acid (3.2).
- Evaporate 25 ml of this extract on the rotary evaporator (see 5.4) nearly to dryness, remove the remaining solvent with a stream of nitrogen (3.9) and redissolve the residue in 25,0 ml of methanol (3.3).
- Evaporate until it had just reached dryness, under reduced pressure at 60 oC by means of the rotary evaporator (4.3). Redissolve the residue in 10,0ml DMF (3.6), add 15,0 ml water (3.1) and mix.