An eco-friendly hydrophilic interaction HPLC method for the determination of renal function biomarkers, creatinine and uric acid, in human fluids

An accurate, robust and environmentally friendly hydrophilic interaction liquid chromatographic (HILIC) method was developed for the determination of renal function biomarkers, creatinine and uric acid, in human urine and tear samples. The sample preparation was simple and fast with the steps of protein precipitation with 2.0 mL of 50% acetonitrile, centrifugation, filtration and dilution. A weak polar cyano HILIC stationary phase with a highly aqueous mobile phase was chosen for the separation to minimize the consumption of harmful organic solvents. This developed HILIC method consumed less than 0.25 mL of acetonitrile per sample separation. Quantitation was carried out by an internal standard method. A good linearity of response in the concentration range of 0.20 to 10.0 mu g mL(-1) creatinine or uric acid with a coefficient R-2 = 0.999 for quantitative analysis was achieved. The detection limits for creatinine and uric acid were 0.04 and 0.06 mu g mL(-1), respectively. This method has been successfully applied for the determination of creatinine and uric acid in human urine and tear samples.