Comparison of SemiQuantitative Cotinine Values Obtained by the DRI Immunoassay and Values Obtained by a Liquid Chromatography–Tandem Mass Spectrometry‐Based Method: The DRI Immunoassay is Suitable for Screening Purposes Only Because Semiquantitative Values May Be Unreliable. Issue 6 (23rd May 2016)

• Record Type: Journal Article
• Authors: Dixon, R. Brent; Dasgupta, Amitava
• Is Part Of: Journal of clinical laboratory analysis. Volume 30:Issue 6(2016:Nov.)
• Page Start: 1106
• Page End: 1109
• Publication Date: 2016-05-23
• Subjects: cotinine -- DRI Assay -- LC/MS/MS -- positive Bias; Diagnosis, Laboratory -- Periodicals; Medical laboratory technology -- Periodicals; 616
• DOI: 10.1002/jcla.21988
• Languages: English
• ISSNs: 0887-8013

Abstract

Abstract : Background: DRI cotinine assay is suitable only for screening for cotinine in urine specimens. We studied the reliability of DRI cotinine semiquantitative values by comparing them with the cotinine concentration obtained with a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method. Methods: Semiquantitative cotinine concentrations in 39 urine specimens obtained by the DRI immunoassay were compared with cotinine concentrations obtained by LC‐MS/MS. Results: The DRI cotinine assay consistently overestimated cotinine values obtained by the LC/MS/MS method ( y = 1.1529 x + 252.24, n = 39, R 2 = 0.8899) indicating that semiquantitative values obtained using the DRI assay may be unreliable. However, no false‐negative results were observed using the DRI assay. Conclusion: DRI cotinine assay is suitable only for screening cotinine in urine specimens.