The determination of bilirubin with a new enzymatic method (Dri-STAT bilirubin) using the Hitachi 704 selective analyzer.

A new enzymatic method for the determination of bilirubin in serum and plasma by means of a Hitachi 704 selective analyzer was evaluated. This endpoint method (37 degrees C) including a sample blank showed very reliable results. The range of linearity was 0.3 to 437 mumol/l bilirubin. The within-run imprecision of three different bilirubin concentrations (n = 16) was 0.37, 0.44 and 0.76% (coefficient of variation). Between-assay imprecision (n = 15) was 0.51 to 1.76% (coefficient of variation) for five different control materials. Inaccuracy, determined with 5 control sera (assigned values: 19, 23.9, 90.7, 142.0 and 295.6 mumol/l bilirubin), was 0.14 to 4.27%. Recovery rates, determined in two spiked plasma samples, were 97.8% and 99.1%, and in six bilirubin standard solutions between 92 and 99%. The comparison with the routinely used 2.5-dichlorophenyl diazonium salt method as well as with the Jendrassik & Grof [1938) Biochem. Z. 297, 81-89) method as the reference yielded correlation coefficients of r = 0.997 and r = 0.998.