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A micellar extraction procedure in situderivatization method was developed for extraction of diethanolamine in cosmetic samples prior to high performance liquid chromatography analysis. The diethanolamine was taken into a complex with dansyl chloride in an aqueous nonionic surfactant, Triton X-114, medium and concentrated in the surfactant-rich phase. Based on method development, the optimum parameters for the micelle-mediated extraction process were as follows: 4.0% (v/v) of Triton X-114, pH = 9, 1.5 g L−1solution of derivative reagent, derivatization time of 15 min and derivatization temperature of 50 °C. In addition, the cloud point pre-concentration was optimized under the condition of 15% (m/v) sodium chloride and equilibration at 60 °C for 10 min. The extract obtained was analyzed by high performance liquid chromatography. The micellar extraction in situderivatization/high performance liquid chromatography method was successfully applied for the determination of trace diethanolamine in cosmetic samples, the limit of detection (LOD) and limit of quantity (LOQ) of diethanolamine were 0.57 μg g−1and 1.72 μg g−1, respectively. Recovery ranged from 89.9% to 96.4% with obtained relative standard deviations (RSDs) of 3.9% to 5.2%, respectively. The derivatization, extraction and enrichment were completed in the same system. The proposed method was a simple, effective and environmental friendly technique for the analysis of diethanolamine.

Micelle-mediated extraction and cloud point preconcentration has been successfully applied to the separation of camptothecin (CPT) from Camptotheca acuminate. The CPT was first extracted from Camptotheca acuminatesamples by aqueous non-ionic surfactant X-114 solution with ultrasonic assistance. A small volume of surfactant-rich phase was then obtained by preconcentrating CPT and analyzed by high performance liquid chromatography. Various experimental conditions were investigated to obtain the highest extraction yield. The optimum parameters for the micelle-mediated extraction process were as follows: Triton X-114 concentration was 7%, pH was 7, the ratio of liquid to solid was 125/1 (mL g−1) and ultrasonic time was 40 min. The highest extraction recovery was obtained with 25% (m/v) sodium chloride and equilibration at 50 °C for 20 min. Compared with other extraction methods, this technique showed significant advantages including low cost and toxicity. In addition, it had the ability to preconcentrate CPT with an enhancement factor of 5 and obtained a higher extraction yield. In this paper, the kinetics of cloud point extraction were also discussed, and the process could be described mathematically by a second-order kinetic model. The limit of detection for CPT was 0.7 μg mL−1. The precision of the proposed method was indicated by a relative standard deviation of 5.4% (n= 5). Finally, the method was successfully applied to extract CPT from Camptotheca acuminatefruit, bark and leaf, and the extraction yields obtained were 0.1157%, 0.0926% and 0.0612%, respectively. The recoveries of CPT were in the range of 92.3–93.6%.