Determination of vitamins B1 and B6 in infant formula and food supplement samples using magnetic layered double hydroxide nanoadsorbent before liquid chromatography-tandem mass spectrometry

Abstract

A magnetic Mg/Fe layered double hydroxide (magnetic LDH) nanocomposite was successfully prepared and used as a suitable adsorbent to simultaneously extract vitamins B1 and B6 from complex infant formula and food supplements. The important parameters affecting the extraction were optimized and the final parameters are as follows; the amount of adsorbent (20 mg), extraction time (6 min), elution time (8 min), and elution solvent ethanol in 750 µL. As-prepared nanoadsorbent was successfully in magnetic solid phase extraction set-up with no hazardous solvents and extraction performed in 6 min. The structure of nanoadsorbnet is lamellar, providing a wide surface to extract the analytes. The quantification of the analytes was accomplished using the liquid chromatography-tandem mass (LC/MS-MS) technique. Under optimum extraction conditions, the linearity ranged from 4 to 1000 ng/mL (vitamin B1) and 20 to 1000 ng/mL (vitamin B6), and the correlation of coefficients (R2) was obtained better than 0.99. The intra-day (n = 3) and inter-day precisions (n = 3 working days) calculated in the form of percent relative standard deviations (%RSDs) were obtained below 10.20%. The proposed method was successfully practiced for analyzing vitamins B1 and B6 in several brands of infant formulas and food supplements.