DETERMINATION OF SUNSCREEN AGENTS AND ULTRAVIOLET STABILIZERS USING UPLC 265 Table IV Percent Recovery of Sunscreen and UV Stabilizers in a BB Cream Matrix Blank Analyte 50% Spike level (%) 100% Spike level (%) 160% Spike level (%) Avobenzone 96.6 98.1 98.0 Butyloctyl Salicylate 100.1 97.5 96.0 DESM 97.5 97.0 96.5 Ensulizole 99.2 98.1 98.1 Octinoxate 98.4 97.5 97.2 Octisalate 98.4 97.5 97.2 Octocrylene 98.1 97.4 96.9 Oxybenzone 99.9 98.2 97.7 Homosalate 98.5 97.6 97.2 BB Cream, Artistry Exact Fit™ Beauty Balm Perfecting Primer Fit™ Beauty Balm Perfecting Primer. Table V Percent Recovery of Sunscreen and UV Stabilizers in the UV Shield Matrix Blank Analyte 50% Spike level (%) 100% Spike level (%) 160% Spike level (%) Avobenzone 98.8 98.4 100.2 Butyl octyl Salicylate 101.8 98.6 99.4 DESM 99.5 98.8 100.2 Ensulizole 99.8 98.6 100.0 Octinoxate 99.7 98.8 100.0 Octisalate 99.9 98.4 99.9 Octocrylene 99.9 98.8 100.0 Oxybenzone 101.1 98.8 99.8 Homosalate 99.7 98.6 99.9 UV Shield, Artistry™ UV Shield SPF 50+ PA+++. purity: 100%) from HallStar (Chicago, IL). Reagent grade trifl uoroacetic acid (TFA) and tetrahydrofuran (THF) were purchased from Fisher Scientifi c, and pyridine from Sigma- Aldrich. HPLC grade methanol was obtained from OmniSolv, Inc. (Charlotte, NC). The cosmetic formulations tested in this method were Artistry Exact Fit™ Beauty Balm Perfecting Primer (BB Cream), an oil-in-water color cosmetic emulsion, and Artistry™ UV Shield SPF 50+ PA+++ (UV Shield) for men, an oil-in-water cream emulsion, sup- plied by Amway Corporation (Ada, MI) both as complete formulations and as formula- tions without sunscreen agents and UV stabilizers to use as blank matrices. STANDARD AND SAMPLE PREPARATION A stock standard solution of avobenzone (1.65 mg/ml), ensulizole (3 mg/ml), octinoxate (8 mg/ml), oxybenzone (0.75 mg/ml), octisalate (5 mg/ml), octocrylene (3.1 mg/ml), and homosalate (20 mg/ml) was prepared in pyridine/methanol (25/75 v/v) solution. Standard solutions for linearity were prepared by pipetting 2.00, 3.00, 5.00, 7.00, and 10.00 ml stock

JOURNAL OF COSMETIC SCIENCE 266 standard solution into a series of 100-ml volumetric fl asks and diluting in THF/methanol (5/95 v/v) solution. A single point standard was similarly prepared by diluting 5.00 ml of the stock solution in a 100-ml volumetric fl ask with a THF/methanol (5/95 v/v) solution. Samples of the BB Cream and UV Shield formulations were weighed (0.75 g) into 100-ml volumetric fl asks, 5 ml THF was added, the samples were briefl y vortexed to break the emul- sions, and then, diluted to volume with methanol. The samples were well mixed and an aliquot fi ltered through a Whatman 25 mm GD/X syringe fi lter with a PVDF with GMF membrane and 0.2-μm pore size (Catalogue Number 6872-2502) into an autosampler vial for analysis. Spiked matrix samples were prepared by weighing 0.75 g of each blank matrix into indi- vidual 100-ml volumetric fl asks. The stock standard was used to spike the matrix blanks with 50%, 100%, and 160% of the nominal concentration of the sunscreen analytes. The samples were dispersed in 5 ml THF, diluted to volume with methanol, well mixed, and an aliquot fi ltered through a Whatman PVDF with GMF 0.2-μm syringe fi lter into an autosampler vial for analysis. UPLC ANALYSIS Chromatographic separation was performed on a Waters Acquity UHPLC chromato- graph with UV detection and an Agilent Poroshell EC-C18 (2.7 μm, 4.6 mm × 100 mm) Figure 3. Representative chromatograms of blank color cosmetic (BB Cream) (A) matrix spiked with stan- dard solution of sunscreen agents and UV stabilizers and (B) blank BB Cream matrix. Standard compounds: (A) ensulizole, (B) oxybenzone, (C) octocrylene, (D) avobenzone, (E) octinoxate, (F) homosalate A, (G) octisalate, (H) homosalate B, (J) DESM, and (K) butyloctyl salicylate.