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Specific method for serum creatinine determination based on ion exchange chromatography and an automated alkaline picrate reaction — A proposed reference method

1978; Elsevier BV; Volume: 11; Issue: 4 Linguagem: Inglês

10.1016/s0009-9120(78)90383-1

1873-2933

Muriel W. Weatherburn, R.B.B. Trotman, S.H. Jackson,

Analytical Chemistry and Sensors

A proposed reference method for serum creatinine has been developed under the auspices of the Committee on Reference Methods and Reference Materials of the Canadian Society of Clinical Chemists. A serum ultrafiltrate at pH 2.0 is applied through a closed sample loop injection system to a short column containing cationic resin of high resolving power. Elution with sodium citrate buffer by means of minipump at constant rate passes the eluate into alkaline picrate reagents in a continuous flow system (Technicon AAIII pump, AAII colorimeter 50 mm x 1.5 mm flow cell, narrow band width filter). The colour reaction peak is monitored visually to verify specificity and the area is calculated electronically. Specificity has been demonstrated by use of Jaffé-reactive substances such as glucose, sodium acetoacetate, L-ascorbic acid, pyruvic acid, L-dopa and glycocyamidine and also by use of an alternate colour reaction, sodium 3,5-dinitrobenzoate in place of alkaline picrate in the analysis of serum pools. Routine methods in common use, i.e., manual and automated alkaline picrate procedures, demonstrated a statistically significant high bias in interlaboratory studies in which this procedure was used for reference.