Premium
Gas chromatography/trace analysis of derivatized azelaic acid as a stability marker
Author(s) -
Alzweiri Muhammed,
Tarawneh Ruba,
Khanfar Mohammad A.
Publication year - 2013
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201300418
Subject(s) - azelaic acid , derivatization , chromatography , chemistry , trimethylsilyl , gas chromatography , silylation , gas chromatography–mass spectrometry , organic chemistry , mass spectrometry , catalysis
Azelaic acid, a naturally occurring saturated dicarboxylic acid, is found in many topical formulations for its various medical benefits or as a byproduct of the oxidative decomposition of unsaturated fatty acids. The poor volatility of azelaic acid hinders its applicability in GC analysis. Therefore, azelaic acid was derivatized by methylation and silylation procedures to enhance its volatility for GC analysis. Accordingly, dimethyl azelate ( DMA ) and di(trimethylsilyl) azelate were synthesized and characterized by GC – MS . Subsequently, a GC with flame ionization detection method was developed and validated to analyze trace amounts of azelaic acid in some marketed skin creams. Unlike DMA , di(trimethylsilyl) azelate was chemically unstable and degraded within few hours. Nonane was used as a stable internal standard. Variability due to derivatization and extraction was controlled by a standard addition procedure. DMA analysis was linear in a wide concentration range (100 ng/mL to 100 mg/mL). Moreover, the method was accurate (96.4–103.4%) and precise with inter‐ and intraday variability <2.0% and LOQ and LOD of 100 and 10 ng/mL, respectively.