The detection of cotinine in hydrolyzed meconium samples

To date, the screening of meconium for the determination of tobacco exposur e in newborns has proven difficult. It was hypothesized that cotinine forms reversible Schiff base bonds with free amino functions on proteins, theref ore, hydrolysis of meconium would be necessary for the detection of 'free' cotinine. One-hundred-and-two (102) meconium samples received into our labo ratory were extracted using a routine non-hydrolysis screening procedure fo r drugs of abuse. Separate aliquots of the specimens were hydrolyzed and re -extracted according to the same procedure. The results of the two methods were compared using a highly specific cotinine micro-plate enzyme immunoass ay procedure (EIA). Of the non-hydrolyzed samples, 33% were positive for co tinine, while 79% of the hydrolyzed samples were cotinine-positive. Common drugs of abuse did not interfere with the analysis. Micro-plate EIA provide s a rapid, simple and reliable screening method for the determination of co tinine in meconium following hydrolysis and extraction. In general, the mec onium specimens received into our laboratory are from newborns considered t o be at risk for post-natal problems due to suspected drug and/or alcohol a buse during pregnancy. (C) 1999 Elsevier Science Ireland Ltd. All rights re served.