Determination and confirmation of isopropyl p-toluenesulfonate in cosmetics by HPLC-diode array detector method and GC-MS

• Published in: International journal of cosmetic science 2016-12, Vol.38 (6), p.627-633
• Main Authors: Tay, B. Y. P., Yung, S. C., Teoh, T. Y.
• Format: Article
• Language: English
• Subjects: Benzenesulfonates - chemistry; chemical analysis; Chromatography; Chromatography, High Pressure Liquid - methods; Cosmetics; Diodes; Gas Chromatography-Mass Spectrometry - methods; GC-mass spectroscopy; HPLC; isopropyl esters; Isopropyl p-toluenesulfonate; Reference Standards; safety testing; Sensors
• ISSN: 0142-5463; 1468-2494
• DOI: 10.1111/ics.12342

Objective Isopropyl p‐toluenesulfonate (IPTS) is a potentially genotoxic by‐product formed during the esterification of palm oil‐based palmitic and palm kernel oil‐based myristic acid with isopropanol to produce isopropyl palmitate or isopropyl myristate. There are no methods described for the analysis of IPTS in cosmetic products. In this work, we have established a simple, precise and accurate method to determine the presence and level of IPTS in various finished cosmetic products which contain palm‐based esters in their formulations. Methods An Agilent 1200 series high‐performance liquid chromatography (HPLC) unit using a diode‐array detector (DAD) has been employed and optimized to detect IPTS in cosmetic products. For the separation, a reverse‐phase Hypersil Gold C8 column (5 μm, 4.6 mm i.d. 250 mm) 5 mM tetrabutylammonium phosphate buffer 50 : 50, (v/v) solution in acetonitrile as mobile phase, in isocratic mode and a flow rate of 0.8 mL min−1 were used. A second method using a gas chromatography/mass selective detector GC–MSD was also developed to confirm the IPTS identity in the cosmetic products. Results Recoveries of IPTS from cosmetic matrices such as a lotion, cleansing milk and a cream ranged from 94.0% to 101.1% with