JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Equipment Figure 11. Sampling equipment and procedure prior to glc analysis. (a) 1. Aerosol samples. Sprayhead removed. Transfer pieces (polyethylene) on. 2. All-glass aerosol bottle 10 ml. Vessel for intermediate transfer. With ordin- ary male valve, without dip tube. 3. Plastic syringe (2 ml). Disposable hospital type. 4. Pressure-Lok A2 Gas Syringe. 25 pl. ['Precision Sampling', Baton Rouge, Louis., USA.] 5. Polyethylene transfer piece. 6. Polyethylene tubing. la (b) Weigh, cool and evacuate the small glass aerosol bottle (2). Remove the spray nozzle of the aerosol sample (1). Introduce by means of plastic transfer pieces, about 8 ml of the pressurized liquid into the small aerosol bottle. Weigh accurately and find the weight of the transferred sample (= m gram). (Facing p. 200)

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (c) Introduce about 1 ml cyclohexane (internal standard) into the small aerosol bottle by means of a plastic disposable syringe (without needle), and plastic transfer pieces (3 and 5). Weigh accurately and find the weight of the internal standard. No phase separation should occur in the liquid mixture. If so, too much cyclohexane has been added. Sampling should be repeated with less cyclohexane. The Pressure-Lok A2 syringe can now be filled with the pressurized liquid mixture in the small glass aerosol bottle. Disconnect the needle of the syringe. Push with the thumb the syringe valve to position 'open'. Slowly move up and downwards the piston several times, taking care that it reaches the syringe bottom completely each time. This is an extremely important operation, which should be carefully done, in order to take a representative sample of the mixture. No gas space should be present in the syringe. Close the syringe valve with the thumb at approx. 20 I. tl. Control for leaks by waiting a minute and holding the syringe piston in a fixed position. No 'gas' space should appear in the syringe. Injection into the gas chromatograph can now be done. Put the needle on the syringe, inject into the septum. Push the valve on 'open' and immediately push down the piston. (Facing p. 201)