Single-pH Extraction Procedure for Detecting Drugs of Abuse

Abstract

Abstract A method is presented for determining certain drugs of abuse in a single extract of urine. The urine sample is adjusted to pH 6.0 with a buffer containing bromcresol purple. Basic drugs, such as amphetamines and narcotics, form an organic salt with the ionized bromcresol purple, which is extractable with a mixture of chloroform and 2-propanol (3:1 by volume). At pH 6.0, weak acids such as barbiturates and neutral drugs such as glutethimide are also soluble in this solvent. Consequently, the major classes of drugs are extracted simultaneously. The extract is then concentrated and the individual drugs are determined by thin-layer chromatography in a solvent that will separate bromcresol purple from the drugs. Additional Keyphrases: drug screening #{ 149} toxicology #{ 149} thin-layer chromatography #{ 149} screening procedure Clinical Laboratory Service, West Side VA Hosp., 820 S. Damen Ave., Chicago, Ill. 60612.