RAPID DISTILLATION COUPLED WITH ION CHROMATOGRAPHY FOR THE DETERMINATION OF SIX ALKYLAMINES IN COSMETICS

Abstract

A rapid distillation method coupled with ion chromatography was developed for simultaneous determination of methylamine, ethylamine, dimethylamine, trimethylamine, propylamine, and butylamine in cosmetics. The distillation system was designed professionally to achieve rapid distillation in less than 3 min and eliminate the interferences of alkali metals, alkaline earth, and organic compounds effectively. Samples were distilled using vapor stream under alkaline conditions and the distilled products were absorbed in acetic acid solution prior to detection. The linear ranges of alkylamines were within 0.1–18 mg/L and the detection limits ranged from 0.045 mg/L to 0.075 mg/L. The method was successfully utilized to determine the amount of alkylamines in commercial cosmetics without need for tedious pretreatments. Average recoveries ranged from 84.4% to 108.5% with relative standard deviations (RSD) in the range of 0.7–7.6%. Validation results indicated that the method was simple, accurate, precise, selective, and suitable for the determination of alkylamines in cosmetics.

Keywords:

• alkylamine
• cosmetics
• ion chromatography (IC)
• rapid distillation
• sample pretreatment
• suppressed conductivity detection health

ACKNOWLEDGMENT

We thank Dr. Lina Liang, Fengqiong Liu, and Zhe Jiao for providing valuable suggestions. This research was supported by the Medical Science Foundation of Guangdong Province (No. A 2006079).

Notes

Note. Relative standard deviation (n = 8).

Note. Average value of six parallel determinations.

Note. Average value of six parallel determinations.

^a Number of this type of cosmetics.

^b Number of this type of cosmetics with concentrations above detection limits.

^c Average value for this type of cosmetics with concentrations above detection limits.

^d Standard deviation calculated using concentrations above detection limits.