Use of the EMITtox serum tricyclic antidepressant assay for the analysis of urine samples.

The EMITtox serum tricyclic antidepressant (TCA) assay is intended for use with serum or plasma. Currently, there are no commercially available immunoassay kits available for the detection of TCAs in urine. The proposed method utilizes the EMITtox serum TCA assay for the direct analysis of urine samples. The minimum detectable concentration of nortriptyline in urine is 25 ng/mL. The within-run CV was determined to be 0.6% and the between-run CV was 2.6%. The TCA assay cross-reacts with phenothiazines and antihistamines. The proposed methodology should be applicable to other EMIT serum assays to allow their use with urine.