[Determination of UV-327 and UV-328 in mouse plasma by high performance liquid chromatography]

To establish a high performance liquid chromatography (HPLC) method for the determination of ultraviolet (UV) absorbers UV-327 and UV-328 in mouse plasma.

N-hexane-acetone (volume ratio 1 ∶1) was added to a mouse plasma sample as the extraction solvent for vortex extraction, and the supernatant was dried at 50 ℃ with nitrogen. Thereafter the residue was redissolved with methanol, centrifuged and filtered. The separation was performed on a Waters SymmetryC₁₈ column (250 mm×4.6 mm, 5 μm), and the concentrations of UV-327 and UV-328 in the mouse plasma were determined by HPLC with an UV detector. The elution was isocratic at a flow rate of 1.0 mL/min with a mobile phase composed of 100% methanol, and the UV detection wavelength was 340 nm. The retention time was used for qualitative analysis, and the internal standard method was used for quantitative analysis using UV-320 as the internal standard.

The calibration curves of UV-327 and UV-328 were linear with correlation coefficients of 0.999 7 over the concentration range of 0.05 to 10.0 mg/L. The limit of detection was 0.01 mg/L, and the limit of quantitation was 0.03 mg/L. The average recoveries at low, medium and high three concentrations (0.50, 1.00, 2.00 mg/L) in the mouse plasma were 91.7%-101.0% for UV-327, and 97.5%-103.9% for UV-328. The intra-day precisions (n=6) of UV-327 were 2.9%-6.6%, and 2.7%-7.4% for UV-328. The inter-day precisions (n=3) of UV-327 were 6.0%-9.3%, and 6.6%-8.6% for UV-328. The extraction recoveries of UV-327 were 98.8%-103.8%, and 99.8%-100.9% for UV-328. The measured relative deviations of UV-327 in the mouse plasma samples placed at room temperature for 6 hours and -40 ℃ for 15 days were 0.9%-3.5% and 7.4%-15.0%, and the measured relative deviations of UV-328 were 2.0%-4.3% and 2.1%-13.8%, respectively. The mouse plasma samples could be stored at room temperature for 6 hours at least and -40 ℃ for 15 days at three spiked concentration levels.

The method was simple and fast with high accuracy, precision and sensitivity, and could be applied to the determination of UV-327 and UV-328 in mouse plasma.