Guterres M. V., Ferreira M. M. C., Volpe P. L. O., “Multiway calibration for creatinine determination by the Jaffé method in human serum”. Seattle, WA, The United States, 22-26/09/2002: Eighth International Conference on Chemometrics in Analytical Chemistry (CAC VIII, CAC-2002). Program and Abstracts Book, 88 (2002). Poster 28.

       Title:   Multiway calibration for creatinine determination by the Jaffé method in human
                   serum

  Authors:    M. V. Guterres, Márcia M. C. Ferreira, P.L.O. Volpe
                   Instituto de Química - UNICAMP; Universidade Estadual de Campinas;
                   Campinas, São Paulo 13081-970; Brazil

Keywords:  creatinine, PARAFAC, Jaffé method

Presenter:  Márcia M. C. Ferreira, marcia@iqm.unicamp.br

            The creatinine level in huma serum samples is currently accepted as an indication of the
presence or absence of renal failure, because the concentration of creatinine in serum is
independent of the nutritional diet. Despite the trend toward the use of enzymes to improve
selectivity for creatinine determination, the classical Jaffé reaction still is used extensively for the
analysis of creatinine in serum. The Jaffé method is based on the spectrophotometric detection of
the complex formed when creatinine reacts with picric acid in an alkaline medium. Although this is
a common method of choice, a more complete understanding of this reaction system and its
interferents than currently exists is needed.

            To improve the performance of the specificity of the Jaffé method, kinetic methods are used
to reduce the effects of the most common interferents: albumin, glucose, bilirubin and acetoacetate.
Nevertheless, to optimize the kinetic method for all interferents, a better methodology is necessary.

            In this work, multiway calibration is proposed to improve the Jaffé method. The
methodology proposed is based on the simulatenous acquisition of the visible spectrum (450-600
nm) at regular time intervals, during a 5 min period. For quantitative determinations, the PARAFAC
method is used. The effect of different experimental conditions and the kinetic behavior are
investigated for the reaction of creatinine with picric acid in an alkaline medium in the presence of
albumin. The results indicate a pseudo-first order mechanism for the creatinine reduction.
Determination of creatinine by the PARAFAC method is possible, even when there is a lack of
selectivity due to the presence of interferents. The proposed mehtod provides good results and is
suitable for creatinine determination in human serum.

             This work is financed by the State of São Paulo Research Foundation (FAPESP).
 
 
 
 

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