Detection of cocaine and its metabolites in breast milk

A method was developed for measuring cocaine and its metabolites, benzoylec gonine, ecgonine methyl ester, norcocaine, ecgonine ethyl ester, cocaethyle ne, and m-hydroxybenzoylecgonine, in breast milk by gas chromatography/mass spectrometry. Limits of detection for this method ranged from 2.5 to 10 ng /mL, and limits of quantitation ranged from 5 to 50 ng/mL. For each of the compounds measured by this method, linear response was demonstrated to 750 ng/mL. Breast milk was collected from I I mothers who admitted to drug use during pregnancy and ten drug-free volunteers serving as control subjects. Cocaine was detected in six of the specimens obtained from drug-exposed sub jects, and in none of the drug-free control subjects. In breast milk specim ens where cocaine and one or more of its metabolites were detected, the con centration of parent compound was greater than any of the metabolites. The highest cocaine concentration found was over 12 mug/mL. Breast-fed infants of cocaine abusing mothers may be exposed to significant amounts of drug or ally.