Comparison Between the Two Methods of Determining for the Content of Phenoxyisopropanol in Cosmetics

OBJECTIVE To determine the content of phenoxyisopropanol in cosmetics by GC and HPLC, to explore the feasibility of GC for determination of phenoxyisopropanol in cosmetics. METHODS GC was determined by using flame ionization detector(FID) with DB-SELECT 624UI capillary column(60 m×0.32 mm, 1.8 μm). The high purity helium was used as the carrier gas with the flow of 1.5 mL·min^-1. The injection volume was 1 mL with the split ratio of 5:1. The injection temperature was 250℃. The column temperature program:initial temperature 65℃, the temperature was raised to 165℃ at the rate of 20℃·min^-1, kept 25 min, then the temperature was raised to 230℃ at the rate of 20℃·min^-1, kept 5 min. The detector temperature of flame ionization detector(FID) was 260℃. The HPLC for the determination of phenoxyisopropanol adopted the 2015 edition of the Safety and Technical Standards for Cosmetics. RESULTS There was no significant difference between the two methods, phenoxyisopropanol could be completely separated from impurities under established GC conditions, the resolution was >1.5, the number of theoretical plate was >10 000; the linear relationship was good in the concentration range of 1-200 mg·mL^-1(r=0.999 9); the limit of quantification was 1.0 mg·mL^-1; the limit of detection was 0.3 mg·mL^-1; the average recoveries were within 84.8%-101.4%; phenoxyisopropanol kept stable within 24 h. CONCLUSION GC established can be used to determine the phenoxyisopropanol content of cosmetics.