SIMULTANEOUS DETERMINATION OF HEAVY METALS 447 Table V Determination of Metals in Cosmetic Products Concentration (µg ml - 1 ) Samples Pb Fe Cu Ni Zn Eyeshadow ,pink 3.7 2.5 679.3 Eyeshadow blue 66.9 715.8 Eyeshadow yellow 7.3 0.3 508.2 Eyeshadow purple 2.2 181.3 Makeup base A 1.3 173.2 Makeup base B 0.5 59.4 Makeup base C 62.7 Foundation A 0.8 116.7 Foundation B 2.2 32.6 Foundation C 8.4 0.5 88.7 Gloss A 1.1 25.6 Gloss B 2.9 2.6 26.9 Gloss C 0.6 26.6 Lipstick A 2.4 0.4 24.1 Lipstick B 17.5 Lipstick C 2.0 23.5 Mascara A 55.7 27.8 Mascara B 52.5 57.3 Mascara C 224.1 68.3 Eyeliner A 342.5 118.0 Eyeliner B 115.7 33.2 Eyeliner C 683.1 78.2 Above are the average concentration values of 3-time injection. Co Cd Mn 3.9 1.7 9.6 metals because of the interference of residual organic materials. The HPLC method is not suitable for the determination of heavy metals. Even though the interference of residual organic materials can be ignored because it is the determination method for organic materials, the HPLC method is not sensitive in analyzing trace heavy metals due to the ion-exchange column in the stationary phase in the system. On the other hand, the Dionex IonPac CSSA analytical column for IC is dedicated to the analysis of heavy metals. The limit of detection (LOD) of IC is higher than in the HPLC method and IC can improve the quality control process in the manufacturing of cosmetics. In this study we have found that the flow rates of the eluent and the post-column reagent are critical to the analysis of heavy metals in cosmetics. The flow rate of the eluent should be two times the flow rate of the post-column reagent, which enables microanalysis because the baseline is most stable under this condition. The concentration of the eluent (PDCA) and the post-column reagent (PAR) are important for the sensitivity and selectivity of the peaks of heavy metals. The sensitivity of the detection can be changed by the concentration combination of PDCA and PAR, and so it is important to look for an optimum concentration combination. CONCLUSIONS We have developed a simultaneous determination method for water-soluble trace heavy metals in cosmetic products and coloring agents. The proposed techniques show that ion

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