Chromatography Forum

dear all,

i am so keen to know about what is the best solvent for folic acid for HPLC analysis.
Here i am doing validation of six water soluble vitamins (B1, B6, Nicotinamide, Folic Acid, Biotin and B2). i m using Methanol and phosphor buffer pH 5 (gradient elution) and yielding good selectivity. but when i started in linierity study i m facing very bad linierity of folic acid, it seems that folic acid was not stabil at the solvent condition.
maybe i should to inform that i m using methanol and phosphor buffer pH 5 (20:80) as solvent. and the solvent mixture having pH for about 5.5

regard
yanti

Folic acid has poor solubility in organic solvents. I have found dilute sodium bicarbonate to be the best solvent, and still it is only about 400 mg/L maximum solubility. It is also very light sensitive. You will need to make it fresh every couple of days, and store it in the refrigerator.

there are many type of solvent for folic acid if you search in USP. the most general is the use of basic solution (e.g. 10% ammonium hydroxide solution in small portion) to enhance folic acid solubility.
you should use low actinic volumetric flask to reduce degradation rate by light.