Quantification of selected fat soluble vitamins and carotenoids in infant formula and dietary supplements using fast liquid chromatography coupled with tandem mass spectrometry

A sensitive and fast analytical method has been developed and validated for the simultaneous identification and quantification of nine fat soluble vitamins and their derivatives (retinol, retinyl acetate, retinyl palmitate, cholecalciferol (D3), α-, β-, γ-, and δ-tocopherol, α-tocopheryl acetate) along with three carotenoids (β-carotene, lutein and zeaxanthin) in dietary supplements and infant formulas using a fast liquid chromatography (UFLC) system coupled with tandem mass spectrometry. Separation was performed within 15 min on a YMC C30 column (100 mm × 2 mm I.D., 3 μm) using methanol:water (90:10 v/v) and tert-butyl methyl ether (TBME):methanol (80:20 v/v) as the mobile phase with gradient elution. Quantification was carried out by multiple reaction monitoring in combination with information dependent acquisition (IDA) using atmospheric pressure chemical ionization (APCI) in the positive mode. Enhanced product ion scan was used and the mass spectrum of each target compound confirmed their presence in the analyzed extracts. Extraction recovery for all analytes spiked at two levels ranged from 90% to 105%. The overall intra-day precision values for the method based on the relative standard deviation for three QC levels were below 6% for all analytes. The accuracy ranged from 87.6% to 113.5%. A selection of multivitamin supplements and infant formulas available on the Canadian market was analyzed and the results showed good agreement with the values declared on the labels.