Simple automated generation of gradient elution conditions in sequential injection chromatography using monolithic...

Area of Science:

• Analytical Chemistry
• Chromatography
• Pharmaceutical Analysis

Background:

• Sequential Injection Chromatography (SIC) offers advantages in automation and reduced solvent consumption.
• Developing gradient elution profiles in SIC can enhance separation efficiency for complex mixtures.
• Accurate quantification of active pharmaceutical ingredients and their impurities is crucial for quality control.

Purpose of the Study:

• To demonstrate a simple, automated method for creating gradient profiles in GE-SIC.
• To validate the method for the separation and simultaneous assay of indomethacin and its degradation products.
• To compare the performance of the novel GE-SIC method with conventional High-Performance Liquid Chromatography (HPLC).

Main Methods:

• Utilized a FIAlab(®) 3000 SIC system with a C18 monolithic column.
• Employed automated mixing of acetonitrile and aqueous phosphoric acid to generate gradient elution.
• Incorporated ketoprofen as an internal standard for quantification.
• Optimized mobile phase composition and flow rate (1.2 mL/min) for separation.

Main Results:

• Achieved excellent chromatographic resolution (R > 2.00) for indomethacin, its degradation products, and the internal standard.
• Demonstrated high repeatability of retention times with relative standard deviation (RSD) values between 0.18-0.30%.
• Reported a short net separation time of 3.5 minutes and low mobile phase consumption (4.5 mL per assay).

Conclusions:

• The automated GE-SIC method provides a feasible and efficient approach for pharmaceutical analysis.
• The developed method exhibits figures of merit comparable to conventional HPLC.
• This technique offers a promising alternative for rapid and automated chromatographic separations.