Development of a multianalyte method based on micro-matrix-solid-phase dispersion for the analysis of fragrance allergens and preservatives in personal care products

Abstract

An effective, simple and low cost sample preparation method based on matrix solid-phase dispersion (MSPD) followed by gas chromatography–mass spectrometry (GC–MS) or gas chromatography-triple quadrupole-mass spectrometry (GC–MS/MS) has been developed for the rapid simultaneous determination of 38 cosmetic ingredients, 25 fragrance allergens and 13 preservatives. All target substances are frequently used in cosmetics and personal care products and they are subjected to use restrictions or labeling requirements according to the EU Cosmetic Directive. The extraction procedure was optimized on real non-spiked rinse-off and leave-on cosmetic products by means of experimental designs. The final miniaturized process required the use of only 0.1g of sample and 1mL of organic solvent, obtaining a final extract ready for analysis. The micro-MSPD method was validated showing satisfactory performance by GC–MS and GC–MS/MS analysis. The use of GC coupled to triple quadrupole mass detection allowed to reach very low detection limits (low ngg−1) improving, at the same time, method selectivity. In an attempt to improve the chromatographic analysis of preservatives, the inclusion of a derivatization step was also assessed. The proposed method was applied to a broad range of cosmetics and personal care products (shampoos, body milk, moisturizing milk, toothpaste, hand creams, gloss lipstick, sunblock, deodorants and liquid soaps among others), demonstrating the extended use of these substances. The concentration levels were ranging from the sub parts per million to the parts per mill. The number of target fragrance allergens per samples was quite high (up to 16). Several fragrances (linalool, farnesol, hexylcinnamal, and benzyl benzoate) have been detected at levels >0.1% (1000μgg−1). As regards preservatives, phenoxyethanol was the most frequently found additive reaching quite high concentration (>1500μgg−1) in five cosmetic products. BHT was detected in eight samples, in two of them (a baby care product and a lipstick) at high concentrations (>1000μgg−1). Methyl paraben was also found at high levels (>1700μgg−1) in three leave-on samples. Finally, triclosan was found at the maximum concentration limit (0.3%) laid down by the European regulation in two deodorant samples, and the total paraben concentration was close to the maximum concentration permitted (0.8%) in one leave-on sample (body milk).