5-Hydroxymethylfurfural content in foodstuffs determined by micellar electrokinetic chromatography

Micellar electrokinetic chromatography (MEKC) has been applied for the determination of 5-hydroxymethylfurfural in several foodstuffs. A 75 mM phosphate buffer solution at pH 8.0 containing 100 mM sodium dodecylsulphate was used as background electrolyte (BGE), and the separation was performed by applying +25 kV in a 50 μm I.D. uncoated fused-silica capillary. Good linearity over the range 2.5–250 mg kg −1 ( r 2 ⩾ 0.999) and run-to-run and day-to-day precisions at low and medium concentration levels were obtained. Sample limit of detection (0.7 mg kg −1 ) and limit of quantification (2.5 mg kg −1 ) were established by preparing the standards in blank matrix. The procedure was validated by comparing the results with those obtained with liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). Levels of HMF in 45 different foodstuffs such as breakfast cereals, toasts, honey, orange juice, apple juice, jam, coffee, chocolate and biscuits were determined.