Human nails metabolite analysis: A rapid and simple method for quantification of uric acid in human fingernail by high-performance liquid chromatography with UV-detection

• We have developed a sensitive, accurate and simple HPLC-UV method for the quantification of UA in human fingernails.
• This determination of UA in the fingernail of healthy men and women volunteers by HPLC-UV is the first reported example.
• As for the concentration of each fingernail, the forefinger, middle finger and third finger are relatively stable.

A rapid and simple analytical method for the quantification of uric acid (UA) in human fingernails by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection is described. UA was extracted from human fingernail samples at 90 °C for 20 min, then separated on an Inertsil ODS-2 column (250 × 4.6 mm I.D., 5.0 μm, GL Sciences) by isocratic elution using methanol: 74 mM phosphate buffer (pH 2.2) 2:98 (v/v). An UV detector was used to monitor at 284 nm. The results indicated that under optimized measurement conditions results were achieved within 8.0 min, and a good linearity was achieved from the calibration curves (r2 > 0.9999) in the range of 1.0–10000 ng; the limit of detection (S/N = 3) was 2.0 pg, the inter-day and intra-day assay precisions were all less than 0.46% and the mean recoveries (%) of the uric acid spiked in the human fingernail were 101.95%. The amounts of UA in the fingernails of healthy volunteers were determined.