Simultaneous determination of cosmetics ingredients in nail products by fast gas chromatography with tandem mass spectrometry

• The first GC–MS/MS method for determining toluene, methylpyrrolidone, benzophenone.
• The first extraction procedure with derivatization using 1–2.5 mL of solvent.
• The first fully validated method with confirmation of the identity to analytes.
• Using isotopically labeled analogues as internal standards to correct recovery.

A rapid and sensitive gas chromatography with tandem mass spectrometry (GC–MS/MS) method has been developed and validated to quantitatively determine cosmetic ingredients, such as toluene, N-methylpyrrolidone, 2,4-dihydroxybenzophenone (benzophenone-1, BP-1), and diethylene glycol dimethacrylate, in nail products. In this procedure, test portions were extracted with acetone, followed by vortexing, sonication, centrifugation, and filtration. During the extraction procedure, BP-1 was derivatized making it amenable to GC–MS analysis, using N,O-​bis(trimethylsilyl)​trifluoroacetamide. The four ingredients were quantified by GC–MS/MS in an electron ionization mode. Four corresponding stable isotopically labeled analogues were selected as internal standards, which were added at the beginning of the sample preparation to correct for recoveries and matrix effects. The validated method was used to screen 34 commercial nail products for these four cosmetic ingredients. The most common ingredients detected in the nail products were toluene and BP-1. Toluene was detected in 26 products and ranged from 1.36 to 173,000 μg/g. BP-1 ranged from 18.3 to 2,370 μg/g in 10 products.