TY - JOUR
T1 - Immunoassay and GC-MS procedures for the analysis of drugs of abuse in meconium
AU - ElSohly, Mahmoud A.
AU - Stanford, Donald F.
AU - Murphy, Timothy P.
AU - Lester, Barry M.
AU - Wright, Linda L.
AU - Smeriglio, Vincent L.
AU - Verter, Joel
AU - Bauer, Charles R.
AU - Shankaran, Seetha
AU - Bada, Henrietta S.
AU - Walls, H. Chip
N1 - Funding Information:
This work was supported in part by NICHDM aternal Lifestyle Study, NIH Grant No. 5-U10-HD27904-02, subcontract from Women and Infants Hospital to ElSohly Laboratories, Incorporated (ELI).T he authors acknowledget he efforts provided by members of the NICHD/NIDAS cientificA dvisory Committee throughout the course of the work: Edward J. Cone, Marilyn Huestis, C. LindseyD e Vane, Bruce Goldberger,A mandaJenkins, Michael R. Baylor, Donna Bush, Robert Stephenson, Diana Wilkins, Doug Rollins, and Petrina Babcock.
PY - 1999
Y1 - 1999
N2 - The analysis of meconium specimens for metabolites of substances of abuse is a relatively accurate method for the detection of fetal exposure to drugs. Most of the methods reported in the literature before the early 1990s relied on radioimmunoassays. The purpose of this study was to develop and validate methods for meconium sample preparation for the screening and gas chromatography-mass spectrometry (GC-MS) confirmation of meconium extracts for cannabinoids, cocaine, opiates, amphetamines, and phencyclidine. EMIT(TM) and TDx(TM) immunoassays were evaluated as screening methods. The sample preparation method developed for screening included extraction and purification prior to analysis. Cutoff levels were administratively set at 20 ng/g for 11-nor-Δ9-THC-9-COOH (THCCOOH) and phencyclidine and at 200 ng/g for benzoylecgonine, morphine, and amphetamines, although lower levels could be detected in meconium using the EMIT-ETS(TM) system. Ninety-five meconium specimens were subjected to the screening procedure with GC-MS confirmation of presumptive positives. In addition, 30 (40 for cocaine) meconium specimens were subjected to GC-MS analysis for all analytes regardless of the screening results to determine the false-negative rate, if any, of the immunoassay. Although there were no false negatives detected, the GC-MS confirmation rate for the immunoassay-positive specimens was generally low, ranging from 0% for amphetamines to 75% for opiates. The lowest rate of confirmed positives was found with the cannabinoids, suggesting that tetrahydrocannabinol (THC) metabolites other than free 11-nor-9-carboxy-Δ9-THC may be major contributors to the immunoassay response in meconium.
AB - The analysis of meconium specimens for metabolites of substances of abuse is a relatively accurate method for the detection of fetal exposure to drugs. Most of the methods reported in the literature before the early 1990s relied on radioimmunoassays. The purpose of this study was to develop and validate methods for meconium sample preparation for the screening and gas chromatography-mass spectrometry (GC-MS) confirmation of meconium extracts for cannabinoids, cocaine, opiates, amphetamines, and phencyclidine. EMIT(TM) and TDx(TM) immunoassays were evaluated as screening methods. The sample preparation method developed for screening included extraction and purification prior to analysis. Cutoff levels were administratively set at 20 ng/g for 11-nor-Δ9-THC-9-COOH (THCCOOH) and phencyclidine and at 200 ng/g for benzoylecgonine, morphine, and amphetamines, although lower levels could be detected in meconium using the EMIT-ETS(TM) system. Ninety-five meconium specimens were subjected to the screening procedure with GC-MS confirmation of presumptive positives. In addition, 30 (40 for cocaine) meconium specimens were subjected to GC-MS analysis for all analytes regardless of the screening results to determine the false-negative rate, if any, of the immunoassay. Although there were no false negatives detected, the GC-MS confirmation rate for the immunoassay-positive specimens was generally low, ranging from 0% for amphetamines to 75% for opiates. The lowest rate of confirmed positives was found with the cannabinoids, suggesting that tetrahydrocannabinol (THC) metabolites other than free 11-nor-9-carboxy-Δ9-THC may be major contributors to the immunoassay response in meconium.
UR - http://www.scopus.com/inward/record.url?scp=0032845143&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032845143&partnerID=8YFLogxK
U2 - 10.1093/jat/23.6.436
DO - 10.1093/jat/23.6.436
M3 - Article
C2 - 10517548
AN - SCOPUS:0032845143
VL - 23
SP - 436
EP - 445
JO - Journal of Analytical Toxicology
JF - Journal of Analytical Toxicology
SN - 0146-4760
IS - 6
ER -