Improved one-step solid-phase extraction method for morphine, morphine-3-glucuronide, and morphine-6-glucuronide from...

Area of Science:

• Analytical Chemistry
• Pharmacology

Background:

• Accurate quantification of morphine and its glucuronides (M3G, M6G) in human plasma is crucial for pharmacokinetic and pharmacodynamic studies.
• Previous solid-phase extraction (SPE) methods suffered from coextraction of endogenous plasma components and late-eluting peaks, complicating analysis and reducing throughput.

Purpose of the Study:

• To develop and validate an improved one-step solid-phase extraction (SPE) method for enhanced recovery of morphine, M3G, and M6G from human plasma.
• To minimize coextraction of interfering endogenous plasma constituents and eliminate cartridge-derived artifacts.
• To reduce chromatographic run-time and increase sample throughput.

Main Methods:

• A modified one-step solid-phase extraction protocol was applied to human plasma samples.
• High-performance liquid chromatography (HPLC) with UV detection was used for the analysis of morphine, M3G, and M6G.
• Extraction efficiencies and reduction in interfering peaks were quantified and compared to a previous method.

Main Results:

• The improved SPE method significantly reduced endogenous plasma component interference by approximately 80% (p < 0.01).
• High extraction efficiencies were achieved for morphine (93.8 ± 2.5%), M6G (91.7 ± 1.7%), and M3G (93.1 ± 2.2%).
• A problematic late-eluting cartridge-derived peak was completely eliminated, and the chromatographic run-time was reduced to 20 minutes, doubling sample throughput.

Conclusions:

• The improved one-step SPE method offers a more efficient and cleaner extraction of morphine and its glucuronides from human plasma.
• This method enhances analytical accuracy by reducing interferences and significantly increases sample throughput.
• The optimized protocol is valuable for routine clinical and research analyses requiring rapid and reliable quantification of these compounds.