DETERMINATION OF BAC IN WET WIPES 7 F values were -0.981 and 0.011 for C10 and C12 derivatives, respectively, by using Mandel test. This situation showed statistically that peak area values of BAC derivatives increased linearly with increasing concentration. In light of this information, calibration curve parameters were evaluated. Resulted parameters are presented in Table II. ACCURACY AND PRECISION Accuracy and precision of the developed method were evaluated at means by recovery and relative standard deviation, respectively. For this purpose, quality control solutions of BAC were investigated. Recovery studies were made by using wetting solution without BAC. Known amount of standard BAC solutions were added to this solution at three dif- ferent concentration levels and analyzed. Recovery values and relative standard deviations for intraday and interday studies are shown in Table III. According to Table III, there were some differences between recovery values. The reasons may be due to little deviations from calibration curve at high and low concentration values. Although these concentration values seem in the linear range according to the Mandel test, in view of recovery studies there were some differences. But this situation did not affect the wet wipe analysis because analysis of the samples was applied at medium concentration value. To evaluate the precision of the developed method, standard solutions of BAC at three different levels were investigated. Retention time and peak area values were compared for both intraday and interday precision study. All results met the validation conditions. ROBUSTNESS AND RUGGEDNESS OF THE METHOD Robustness and ruggedness of the method were investigated. For this purpose, some parameters of the method were changed deliberately as declared in USP between ±10% rate. These parameters were percent of ACN in supporting electrolyte, pH value of sup- porting electrolyte, and wavelength of the detector. Measurements were done in triplicate on different days. All results obtained are presented in Table IV. Table III Calculated Recovery and RSD Values for Known Concentration of BAC at Different Concentrations Concentration Level Intraday Interday C10 derivative C12 derivative C10 derivative C12 derivative R RSD R RSD R RSD R RSD Low 109.34 3.15 112.25 4.34 106.26 3.05 108.34 4.26 Medium 98.81 0.52 98.67 0.74 98.95 1.03 98.32 1.01 High 105.91 1.20 107.89 4.44 103.05 2.77 104.66 3.08 R: recovery % RSD: relative standard deviation of the results. Low, medium, and high concentration values were selected as 0.0075, 0.06, and 0.2 mg/ml BAC.

JOURNAL OF COSMETIC SCIENCE 8 ANALYSIS OF THE WET WIPES For this purpose, different wet wipes were bought from the market. Commercial wet wipe solutions were analyzed by using the developed CE method for the determination of BAC. Every sample was analyzed by using calibration curve obtained in same day and amount of BAC was calculated according to the recovery values of quality control sam- ples. Recovery values for BAC were different for each day due to different surface effect of the wipe tissues. Hence, there was no constant value to calculate the real amount of BAC in samples. Obtained results were presented in Table V. CONCLUSIONS In this study, the CE method used for the quantitative determination of BAC has been developed and validated. Satisfactory validation data were achieved for sensitivity, linear- ity, accuracy, precision, robustness, and ruggedness. The developed method has some ad- vantages by comparing literature. Other studies reported LOD values between 1 and 10 μg/ml which were higher than the reported value in this study. Only one study declared an LOD value as 0.01 μg/ml because they investigated the BAC in environmental samples and used a liquid chromatography–mass spectrometry/mass spectrometry (MS) device which makes the analysis more complex. The LOD values of the developed method were Table IV RSD Values of Recovery Studies of the Robustness and Ruggedness Test for the Developed Method ACN (%) pH Wavelength Concentration level 28 32 5.8 6.2 212.2 216.2 C10 Low 1.16 3.50 2.55 2.28 3.05 4.40 Medium 2.50 3.49 6.12 5.80 1.93 1.97 High 3.08 3.88 5.81 3.35 5.33 4.95 C12 Low 1.60 2.78 3.42 1.37 4.02 6.40 Medium 2.48 3.82 1.50 5.82 2.09 1.96 High 3.41 3.39 6.24 3.55 5.41 4.89 RSD: relative standard deviation. Table V Analysis Results of Some Commercial Wet Wipe Samples Sample Claimed amount of BAC (mg/ml) Found amount of BAC (mg/ml) C10 C12 C10 C12 Wipe 1 0.280 0.115 0.269 ± 0.04 0.111 ± 0.02 Wipe 2 0.280 0.115 0.267 ± 0.05 0.127 ± 0.02 Wipe 3 0.280 0.115 0.285 ± 0.06 0.114 ± 0.02