Quantitative determination of cocaine, cocaethylene (ethylcocaine), and metabolites in plasma and urine by high-performance liquid chromatography

J. Sukbuntherng, A. Walters, Hsiao-Hui Chow, Michael Mayersohn

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22 Citations (Scopus)

Abstract

A sensitive HPLC assay was developed to quantitate the relatively nonpolar compounds cocaine, cocaethylene (ethylcocaine), norcocaine, and norcocaethylene, as well as the relatively polar metabolites benzoylecgonine and benzoylnorecgonine, in rat plasma and urine. The assay in plasma employed two successive liquid-liquid extractions and separate injections onto two different columns (C8 and C18) to separate and quantitate the relatively polar and nonpolar compounds. In urine, the procedure employed a liquid- liquid extraction followed by solid-phase extraction (C18 light-load cartridges) and two separate injections as for plasma. The UV absorbance of the effluent was monitored at 235 nm. Linear standard curves were obtained over the concentration ranges of 25 to 1000 ng/mL and 5 to 250 ng/mL in plasma and urine, respectively. The inter- and intraday coefficients of variation for the assay of all compounds in plasma and urine were <18% at low concentrations (12.5100 ng/mL) and <12% at high concentrations (125-250 ng/mL). There was no degradation of these compounds during the extraction procedure or during 2 months of storage at -20 °C. The quantitation limits for the assay of the relatively nonpolar and polar compounds in plasma were 25 (2.5 ng in 0.1 mL) and 50 ng/mL (5 ng in 0.1 mL), respectively. For the assay in urine, the quantitation limits were 5 (2.5 ng in 0.5 mL) and 12.5 ng/mL (6.25 ng in 0.5 mL) for the assay of the relatively nonpolar and polar compounds, respectively. The methods have been applied to quantitate those compounds in rat plasma.

Original languageEnglish (US)
Pages (from-to)799-804
Number of pages6
JournalJournal of Pharmaceutical Sciences
Volume84
Issue number7
DOIs
StatePublished - 1995

Fingerprint

High performance liquid chromatography
Metabolites
Cocaine
High Pressure Liquid Chromatography
Assays
Urine
Plasmas
Liquid-Liquid Extraction
Liquids
Rats
Injections
Solid Phase Extraction
cocaethylene
Effluents
Light
Degradation

ASJC Scopus subject areas

  • Drug Discovery
  • Organic Chemistry
  • Chemistry(all)
  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science

Cite this

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title = "Quantitative determination of cocaine, cocaethylene (ethylcocaine), and metabolites in plasma and urine by high-performance liquid chromatography",
abstract = "A sensitive HPLC assay was developed to quantitate the relatively nonpolar compounds cocaine, cocaethylene (ethylcocaine), norcocaine, and norcocaethylene, as well as the relatively polar metabolites benzoylecgonine and benzoylnorecgonine, in rat plasma and urine. The assay in plasma employed two successive liquid-liquid extractions and separate injections onto two different columns (C8 and C18) to separate and quantitate the relatively polar and nonpolar compounds. In urine, the procedure employed a liquid- liquid extraction followed by solid-phase extraction (C18 light-load cartridges) and two separate injections as for plasma. The UV absorbance of the effluent was monitored at 235 nm. Linear standard curves were obtained over the concentration ranges of 25 to 1000 ng/mL and 5 to 250 ng/mL in plasma and urine, respectively. The inter- and intraday coefficients of variation for the assay of all compounds in plasma and urine were <18{\%} at low concentrations (12.5100 ng/mL) and <12{\%} at high concentrations (125-250 ng/mL). There was no degradation of these compounds during the extraction procedure or during 2 months of storage at -20 °C. The quantitation limits for the assay of the relatively nonpolar and polar compounds in plasma were 25 (2.5 ng in 0.1 mL) and 50 ng/mL (5 ng in 0.1 mL), respectively. For the assay in urine, the quantitation limits were 5 (2.5 ng in 0.5 mL) and 12.5 ng/mL (6.25 ng in 0.5 mL) for the assay of the relatively nonpolar and polar compounds, respectively. The methods have been applied to quantitate those compounds in rat plasma.",
author = "J. Sukbuntherng and A. Walters and Hsiao-Hui Chow and Michael Mayersohn",
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T1 - Quantitative determination of cocaine, cocaethylene (ethylcocaine), and metabolites in plasma and urine by high-performance liquid chromatography

AU - Sukbuntherng, J.

AU - Walters, A.

AU - Chow, Hsiao-Hui

AU - Mayersohn, Michael

PY - 1995

Y1 - 1995

N2 - A sensitive HPLC assay was developed to quantitate the relatively nonpolar compounds cocaine, cocaethylene (ethylcocaine), norcocaine, and norcocaethylene, as well as the relatively polar metabolites benzoylecgonine and benzoylnorecgonine, in rat plasma and urine. The assay in plasma employed two successive liquid-liquid extractions and separate injections onto two different columns (C8 and C18) to separate and quantitate the relatively polar and nonpolar compounds. In urine, the procedure employed a liquid- liquid extraction followed by solid-phase extraction (C18 light-load cartridges) and two separate injections as for plasma. The UV absorbance of the effluent was monitored at 235 nm. Linear standard curves were obtained over the concentration ranges of 25 to 1000 ng/mL and 5 to 250 ng/mL in plasma and urine, respectively. The inter- and intraday coefficients of variation for the assay of all compounds in plasma and urine were <18% at low concentrations (12.5100 ng/mL) and <12% at high concentrations (125-250 ng/mL). There was no degradation of these compounds during the extraction procedure or during 2 months of storage at -20 °C. The quantitation limits for the assay of the relatively nonpolar and polar compounds in plasma were 25 (2.5 ng in 0.1 mL) and 50 ng/mL (5 ng in 0.1 mL), respectively. For the assay in urine, the quantitation limits were 5 (2.5 ng in 0.5 mL) and 12.5 ng/mL (6.25 ng in 0.5 mL) for the assay of the relatively nonpolar and polar compounds, respectively. The methods have been applied to quantitate those compounds in rat plasma.

AB - A sensitive HPLC assay was developed to quantitate the relatively nonpolar compounds cocaine, cocaethylene (ethylcocaine), norcocaine, and norcocaethylene, as well as the relatively polar metabolites benzoylecgonine and benzoylnorecgonine, in rat plasma and urine. The assay in plasma employed two successive liquid-liquid extractions and separate injections onto two different columns (C8 and C18) to separate and quantitate the relatively polar and nonpolar compounds. In urine, the procedure employed a liquid- liquid extraction followed by solid-phase extraction (C18 light-load cartridges) and two separate injections as for plasma. The UV absorbance of the effluent was monitored at 235 nm. Linear standard curves were obtained over the concentration ranges of 25 to 1000 ng/mL and 5 to 250 ng/mL in plasma and urine, respectively. The inter- and intraday coefficients of variation for the assay of all compounds in plasma and urine were <18% at low concentrations (12.5100 ng/mL) and <12% at high concentrations (125-250 ng/mL). There was no degradation of these compounds during the extraction procedure or during 2 months of storage at -20 °C. The quantitation limits for the assay of the relatively nonpolar and polar compounds in plasma were 25 (2.5 ng in 0.1 mL) and 50 ng/mL (5 ng in 0.1 mL), respectively. For the assay in urine, the quantitation limits were 5 (2.5 ng in 0.5 mL) and 12.5 ng/mL (6.25 ng in 0.5 mL) for the assay of the relatively nonpolar and polar compounds, respectively. The methods have been applied to quantitate those compounds in rat plasma.

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