Three effective ingredients, dl-α-tocopheryl acetate (TA), dipotassium glycyrrhizinate (PG) and β-glycyrrhetinic acid (GA) in aerosol hair growers were determined using a complete closed sampling system connected to a liquid chromatograph. The aerosol solution in the sample aerosol was induced into a six-way valve and then into a drain valve by a Teflon tube. The sample aerosol and the six-way valve were immersed in a water bath at 3±0.3°C. After regulating the drain valve to prevent emerging bubbles from the Teflon tube, the six-way valve was switched, and the aerosol solution in the 7.30μl of loop on the six-way valve was led to the liquid chromatograph. The standard solution containing effective ingredients instead of the sample aerosol solution was injected with a 5ml syringe. A photo-diode array detector was used for qualitative and quantitative liquid chromatographic analysis. By this method, errors originated from the determination could be completely eliminated. These errors arose from the air-borne loss of nebulized sample and the lower weight estimation of the sample solution caused by dissolving propellant, and they were often detected in the sampling procedure of aerosol solution in the conventional way. This method enabled us a constant quantitative sampling by inducing the aerosol solution into the quantitative loop as a liquid . And also by this method the unit of analytical results could be obtained as weight per volume percentage, not as weight per weight percentage of that values which might vary due to the specific gravity of the liquefied propellant or volatile solvents vaporized after the use of aerosol. The recoveries of TA, PG, GA added to commercial aerosol hair growers were 93.3-101.0%. The analytical results of seven commercial aerosol hair growers were 0.02-0.06% (w/v) for TA, 0.04-0.08% (w/v) for PG and 0.02-0.08% (w/v)for GA.
