A competitive enzyme immunoassay for albuterol: its application for the drug screening in urine.

A competitive enzyme immunoassay using purified monoclonal IgG1 and an alkaline phosphatase-albuterol derivative has been developed for the quantification of albuterol in urine. The calibration curve obtained in optimal incubation conditions is characterized by a minimum detectable level of 26 fmol/well and a working range from 52 fmol to 4,2 pmol/well. This method allows the precise and accurate quantification of albuterol in horse urine without any clean up or extraction step. Moreover the definition of its specificity shows a cross-reactivity of the antibody with the glucurono-/sulfo-conjugates of albuterol. This property is particularly interesting for the screening of urinary albuterol residues in meat producing animals.