Extraction and Determination of Phenolic Acids and Vitamin B of Sieved and Unsieved Wheat Grain by MEKC

Abstract

An MEKC method has been used to separate m-coumaric acid, ferulic acid, syringic acid, vanillic acid, p-coumaric acid, 4-hydroxybenzoic acid, caffeic acid, gallic acid, and 3,4-Dihydroxy benzoic acid, along with Vitamins B₁ and B₆ from uncoated fused silica capillary of 60.2 cm total length, 50 cm effective length, and 75 µm id. Optimum separation was achieved with BGE comprised of sodium tetraborate buffer (50 mmolL⁻¹), pH 9.0, Sodium dodecylesulfate (SDS) (10 mmolL⁻¹), and normal propanol (4% v/v), the optimum ratio was 70:20:10 (Borate:SDS:Propanol) with applied voltage of 20 kV at a wavelength of 225 nm. Linear calibration range and limit of detection (LOD) observed for the analytes were in the range 0.1–100 mgL⁻¹ and 0.032–0.068 mgL⁻¹, respectively. Calculated recoveries of analytes by standard addition were in the range 96–102% with RSD of 0.98–1.43%. Phenolic acids: ferulic acid, p-coumaric acid, and syringic acid were identified along with m-coumaric acid which is being reported for the first time from wheat varieties. The amount of phenolic acids in unsieved wheat grain were found to be higher than sieved wheat grains. Acid hydrolysis was found to release vitamin B along with phenolic acids, whereas methnol/water extraction system released phenolic acids only.

Keywords:

• ferulic acid
• m-coumaric acid
• MEKC
• organic modifier
• phenolic acids
• vitamin B
• wheat

Notes

^a LOD = 3(SD/Slope).

^b LOQ = 10 (SD/Slope).

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