Determination of thiamine in pharmaceutical preparations by sequential injection renewable surface solid-phase...

Area of Science:

• Analytical Chemistry
• Spectrofluorometry
• Separation Science

Background:

• Thiamine determination typically involves oxidation to fluorescent thiochrome followed by solvent extraction.
• Solid-phase extraction (SPE) offers an alternative for isolating and concentrating analytes.
• Microbeads offer a renewable surface for SPE applications.

Purpose of the Study:

• To develop a novel sequential injection renewable surface solid-phase spectrofluorometry method for thiamine determination.
• To utilize octadecyl-alklylated poly[styrene/divinylbenzene] (C18-PS/DP) microbeads for thiochrome adsorption and fluorescence detection.
• To optimize the method for high sample throughput and low detection limits.

Main Methods:

• Sequential injection system coupled with a chip-based flow-through cell.
• Solid-phase extraction using C18-PS/DP microbeads for thiochrome separation.
• Spectrofluorometric detection with excitation at 385 nm and emission at 433 nm.

Main Results:

• Achieved a detection limit of 0.03 µg/mL for thiamine.
• Demonstrated a sample throughput of 30 samples per hour.
• Obtained a relative standard deviation of 1.0% for replicate standard solutions.
• Successfully applied the method to quantify thiamine in pharmaceutical preparations.

Conclusions:

• The developed sequential injection solid-phase spectrofluorometry method is efficient for thiamine determination.
• The use of renewable C18-PS/DP microbeads provides a sensitive and robust analytical approach.
• This method offers a viable alternative to traditional solvent extraction techniques for thiamine analysis in pharmaceuticals.