Volatile methylsiloxanes in personal care products - Using QuEChERS as a "green" analytical approach

Organosiloxanes, namely volatile methylsiloxanes (VMSs) are one of the most relevant classes of ingredients incorporated in personal care products (PCPs), such as creams and lotions, bath soaps and hair care products. Their use has caused concern among the scientific community due to their potential toxic behaviour to human health and environment. This manuscript reports the first application of QuEChERS ("Quick, Easy, Cheap, Effective, Rugged and Safe") extraction followed by gas chromatography - mass spectrometry analysis to determine VMSs in cosmetics and personal care products. Eight VMSs, four linear (L2-L5) and four cyclic (D3-D6) were investigated in 36 samples. The validated method was able to remove the interfering matrix components, conducting to high recovery percentages (74-104%) and low relative standard deviations (<18%). A linear behaviour was observed in the range of 0.005-2.50mgL(-1) (correlation coefficient, R(2)>0.996) and limits of detection ranged from 0.17ngg(-1) (L2) to 3.75ngg(-1) (L5). Matrix effects were also investigated for all analysed compounds and matrices and showed not to be significant. Global uncertainty of the proposed methodology was also estimated using a bottom-up approach being between 5% and 35% (on average). Finally, the method was satisfactorily applied to the analysis of 36 personal care products. As expected, results showed the existence of VMSs in all analysed samples in concentrations up to 754µgg(-1). D4 and D5 were more frequently detected while body moisturizers, facial creams and shampoos showed the highest levels of VMSs.