Determination of pyruvic acid by using enzymic fluorescence capillary analysis

A new method (P-LE–FCA) for the determination of pyruvic acid was proposed based on liquid enzyme method (LE) and fluorescence capillary analysis (FCA). The optimum experimental conditions were as follows: the excitation and emission wavelengths were 350 and 460 nm, respectively; the reaction time and temperature were 20 min and 38 °C, respectively; the pH of phosphate buffer solution was 7.5; the concentrations of nicotinamide adenine dinucleotide and lactate dehydrogenase were 1.0 mmol L−1 and 5.0 kU L−1, respectively. The linear range of this method was 0.2–1.2 mmol L−1 (ΔF = 327.13C–10.018, r = 0.9942). Its detection limit was 0.012 mmol L−1. And its relative standard deviation was 0.86%. Only 18 μL of total reaction solution is enough for the detection. P-LE–FCA has some merits such as lower cost, simple operation procedure and micro determination. It has been used for the determination of pyruvic acid content in human urine samples.