A Novel Fast HPLC-UV Method for Menaquinone-7 Determination in Fermentation Broth

Area of Science:

• Analytical Chemistry
• Biochemistry
• Microbiology

Background:

• Menaquinone-7 (MK-7) is vital for bone and cardiovascular health, commonly found in supplements and foods.
• Accurate quantification of MK-7 in biological matrices is essential for quality control and production optimization.

Purpose of the Study:

• To develop and validate a rapid, sensitive, and reliable HPLC-UV method for MK-7 quantification.
• To enable efficient analysis in complex biological samples like Bacillus subtilis fermentation broth.

Main Methods:

• Thermo-acidic extraction (5% H2SO4 and ethanol) for single-step isolation of MK-7.
• Reverse-phase HPLC with a C8 column and UV detection at 268 nm.
• Isocratic elution with a 3-minute run time for fast analysis.

Main Results:

• The method achieved high sensitivity with an LOQ of 0.10 μg/mL and LOD of 0.03 μg/mL.
• Quantification accuracy ranged from 0.10-18.00 μg/mL with precision (RSD% < 5%) and high recoveries (96.0%-108.9%).
• No derivatization was required, simplifying the extraction process.

Conclusions:

• The validated HPLC-UV method is suitable for routine analysis of MK-7 in fermentation broths.
• This method supports screening of MK-7 producing bacterial strains and quality control in nutraceutical and food industries.