A stir foam composed of graphene oxide, poly(ethylene glycol) and natural latex for the extraction of preservatives and antioxidant

A stir foam composed of graphene oxide, poly(ethylene glycol) and natural latex (GO-PEG-NL) was prepared for use in microsolid phase extraction sorbent of preservative agents and antioxidants from cosmetic products. The extracted analytes were quantified by GC-MS. Under the optimized conditions, the calibration plots are linear in the concentration ranges between 5.0 mu g.L-1 to 1.0 mg.L-1 for benzoic acid, of 10.0 mu g.L-1 to 1.0 mg.L-1 for 2-methyl-3-isothiazolinone (MI), and between 1.0 mu g.L-1 and 1.0 mg.L-1 for both 3-tert-butyl-4-hydroxyanisole (BHA) and 2,6-di-tert-butyl-p-hydroxytoluene (BHT). The LODs are 1.0 mu g.L-1 for benzoic acid, 5.0 mu g.L-1 for MI and 0.5 mu g.L-1 for both BHA and BHT. The stir-foam can be easily prepared, is inexpensive and well reproducible (RSDs < 3%, for n = 6). It can be re-used for up to 12 times after which extraction efficiency has dropped to 90%. The method was successfully applied to the determination of preservatives and antioxidants in cosmetic samples. Recoveries from spiked samples ranged between 94.5 +/- 2.1% and 99.8 +/- 1.8%.