کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1171707 | 1491177 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Development and validation of a reversed-phase ion-pair liquid chromatography method for the determination of magnesium ascorbyl phosphate and melatonin in cosmetic creams Development and validation of a reversed-phase ion-pair liquid chromatography method for the determination of magnesium ascorbyl phosphate and melatonin in cosmetic creams](/preview/png/1171707.png)
A reversed-phase ion-pair high-performance liquid chromatographic method was developed and validated for the determination of magnesium ascorbyl phosphate and melatonin in cosmetic creams. The determination was performed on a BDS C 18 analytical column (250 × 4.6 mm i.d., 5 μm particle size); the mobile phase consisted of 0.020 M tetrabutylammonium hydroxide and 0.025 M potassium dihydrogen phosphate (pH 6.8) mixed with acetonitrile in a ratio (77:23, v/v) and pumped at a flow rate 1.00 ml min−1. The UV detector was operated at 260 nm. The retention times of the magnesium ascorbyl phosphate, melatonin and chlorthalidone that was used as internal standard, were 6.55, 9.18 and 11.07 min, respectively. Calibration graphs are linear (r better than 0.9990, n = 6), in concentration range 1.00–10.00 μg ml−1 for magnesium ascorbyl phosphate and 0.63–6.25 μg ml−1 for melatonin. The intra- and inter-day R.S.D. values were less than 6.0%, while the relative percentage error Er was less than 3.5% (n = 5). The quantitation limits were 0.69 and 0.47 μg ml−1, for magnesium ascorbyl phosphate and melatonin, respectively. The method was applied to the analysis of a cosmetic cream and proved to be suitable for rapid and reliable quality control.
Journal: Analytica Chimica Acta - Volumes 573–574, 28 July 2006, Pages 284–290