Multicommutated flow analysis system for determination of creatinine in physiological fluids by Jaffe method

•Optoelectronic photometric device for Jaffe method has been developed.•The detector has been adapted for measurements under flow analysis conditions.•The multicommuted flow system is useful for analysis of human serum and urine. For the needs of photometric determination of creatinine according to Jaffe protocol a dedicated paired emitter detector diode (PEDD) detector has been developed. This PEDD device has been constructed in the compact form of flow-through cell (30μL total volume and 7mm optical pathlength) integrated with 505nm LED-based emitter and 525nm LED-based detector compatible with multicommutated flow analysis (MCFA) system. This fully mechanized MCFA system configured of microsolenoid valves and pumps is operating under microprocessor control. The developed analytical system offers determination of creatinine in the submillimolar range of concentrations with detection limit at ppm level. The throughput offered by the system operating according to multi-point fixed-time procedure for kinetic measurements is 15–40 samples per hour depending on the mode of measurements. The developed PEDD-based MCFA system has been successfully applied for the determination of creatinine in real samples of human urine as well as serum. The developed sampling unit used the system is free from effects caused by differences in sample viscosity.