title: Quantitative determination of octadecenedioic acid in human skin and transdermal perfusates by gas chromatography-mass spectrometry.
abstract: A gas chromatographic (GC) method with mass spectrometric (MS) detection is developed and validated for the accurate and precise determination of octadecenedioic acid (C18:1 DIOIC) in human skin samples and transdermal perfusates. C18:1 DIOIC is extracted using methanol. The saturated analogue 1,18-octadecanedioic acid (C18:0 DIOIC) is added as internal standard. Prior to analysis, both compounds are converted to their trimethylsilylated derivatives using N,O-bis(trimethylsilyl)trifluoroacetamide with 15% trimethylchlorosilane. Quantitation is performed in selected ion monitoring mode with a limit of quantitation of 250 ng/mL. Linearity with a correlation coefficient of 0.998 is obtained over a concentration range of 250-2000 ng/mL. Values for within-day accuracy range from 94.5% to 102.4%, and from 97.5% to 105.8% for between-day accuracy. Within- and between-day precision values are better than 5% and 7%, respectively. The recovery values from the various matrices vary from 92.6% to 104.0%. The GC-MS method is employed for the determination of C18:1 DIOIC after application of an emulsion containing the active ingredient onto human skin in vitro. The results demonstrate that the method is suitable for the determination of C18:1 DIOIC in human skin samples and transdermal perfusates.
authors.affiliation: School of Pharmacy, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa. anja_judefeind@wisc.edu
authors.forename: Anja
authors.initials: A
authors.lastname: Judefeind
authors.forename: Peet
authors.initials: P
authors.lastname: Jansen van Rensburg
authors.forename: Stephan
authors.initials: S
authors.lastname: Langelaar
authors.forename: Johann W
authors.initials: JW
authors.lastname: Wiechers
authors.forename: Jeanetta
authors.initials: J
authors.lastname: du Plessis
mesh_terms: D002138:Calibration; D003998:Dicarboxylic Acids / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D010477:Perfusion; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000737:chemistry*
chemical_list: D003998:Dicarboxylic Acids; C528535:octadecenedioic acid