Multicommutated flow analysis system for determination of total protein in cerebrospinal fluid

A fully mechanized, computer-controlled, multicommutated flow analysis (MCFA) system dedicated for total protein determination in cerebrospinal fluid samples has been developed. For the protein determination the Exton method has been applied. Dedicated turbidimetric and nephelometric flow-through detectors operating according to paired-emitter detector diode principle have been fabricated by integration of two or three respective light emitting diodes. The developed MCFA system is characterized by robust, compact design and low consumption of the sample (72 μL). The limits of detection for turbidimetric and nephelometric detection mode are 65 mg L−1 and 9 mg L−1, respectively. For turbidimetric measurements the range of linear response offered by the MCFA system is 72–900 mg L−1, whereas in the case of nephelometric detection 18–500 mg L−1 linear range is obtained. The throughput of the MCFA system is over 30 injection per hour. The analytical system was optimized with bovine serum albumin standards and successfully validated with real samples of human cerebrospinal fluid.