title: Determination of ecgonine and seven other cocaine metabolites in human urine and whole blood by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry.
abstract: Ecgonine is suggested to be a promising marker of cocaine (COC) ingestion. A combined mass spectrometry (MS) and tandem MS (MS/MS) method was developed to simultaneously determine ecgonine and seven other metabolites of cocaine in human urine and whole blood with ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The compounds were extracted from as little as 100 μL of sample by solid-phase extraction with a 96-well μElution solid-phase extraction plate. The protonated molecules or fragment ions at accurate mass acquired in MS mode were used to quantify specific analytes, following by dedicated MS/MS identification. The assay was linear in the range from 5 to 50-100 ng/mL for urine samples, except for ecgonine methyl ester (10-200 ng/mL) and ecgonine (40-400 ng/mL), and was linear from 1-2 to 50 ng/mL for whole blood samples, except for ecgonine methyl ester (20-1,000 ng/mL) and ecgonine (40-2,000 ng/mL). The correlation coefficients were all greater than 0.99. The limits of detection ranged from 0.2 to 16 ng/mL, and the lower limits of quantification ranged from 1 to 40 ng/mL. The repeatability and intermediate precision were 18.1% or less. The accuracy was in the range from 80.0 to 122.9%, process efficiencies were in the range from 8.6 to 177.4%, matrix effects were in the range from 28.7 to 171.0%, and extraction recoveries were in the range from 41.0 to 114.3%, except for ecgonine (12.8% and 9.3% at low and high concentrations, respectively). This method was highly sensitive in comparison with previously published methods. The validated method was successfully applied to the analysis of real samples derived from forensic cases, and the results verified that, on the basis of data from four positive samples, ecgonine is a promising marker of cocaine ingestion.
authors.affiliation: State Key Laboratory of New Drug and Pharmaceutical Process, Shanghai Institute of Pharmaceutical Industry, 200040, Shanghai, China.
authors.forename: Lingjuan
authors.initials: L
authors.lastname: Xiong
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Liang
authors.forename: Fangqi
authors.initials: F
authors.lastname: Cao
authors.forename: Yulan
authors.initials: Y
authors.lastname: Rao
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Libo
authors.initials: L
authors.lastname: Zeng
authors.forename: Chunfang
authors.initials: C
authors.lastname: Ni
authors.forename: Haiying
authors.initials: H
authors.lastname: Ye
authors.forename: Yurong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003042:Cocaine / Q000031:analogs & derivatives* / Q000097:blood* / Q000737:chemistry / Q000652:urine*; D006801:Humans; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C005617:ecgonine; D003042:Cocaine