the diazonium compound to the liquid sample the dry analysis process on the other hand normally utilizes a dry analytical element in the form of a test strip which comprises a paper or other absorbent sheet material impregnated with the diazonium compound which produces a color on contact with a bilirubin containing analyte the most commonly used diazo reagent in the wet analysis process is diazotized sulfanilate other suitable diazonium salts employed in the bilirubin wet analysis method include halobenzenediazonium salts such as 2 4 dichlorophenyldiazonium salt and 2 chloro 4 nitrophenyl diazonium salt diazonium reagents commonly used in the dry analysis process include for instance 2 methoxy 4nitrophenyldiazonium tetraborate 2 methoxy 5 tetradecyloxycarbonyl benzenediazonium tetrafluoroborate 2 ethyoxy 5 hexadecyloxycarbonyl benzenediazonium hexafluoroborate etc bilirubin and its conjugates in the presence of the diazo reagents react to produce a product that is purple in color and that can be measured spectrophotometrically at 535 nm the nccls accepted reference method is based on the jendrassik graf principle as developed by dorimas et al dorimas b t perry v w boyse d d et al clin chem 29 297 301 1983 but most users and clinical analyzers use the method of evelyn malloy referenced above the following examples are given to further illustrate the present invention.