Development of liquid chromatography-mass spectrometry method to determine biotin content in nutritional products and supplements

The study was carried out to develop a method for determining the biotin content in nutritional products and supplements by liquid chromatography-mass spectrometry (LC-MS/ MS) combined with a fast and simple pretreatment. The analyzed sample was hydrolyzed in acetate buffer (50 mM, pH 4) with the presence of ascorbate solution (10%) at 120 ± 1°C. After adding the internal standard (2H4-biotin), the mixture was analyzed on LC-MS/ MS system using C18 (100 mm × 2.1 mm; 1.7 µm) column and 0.1% formic acid and MeOH as mobile phases. The analyte was detected on an MS/MS system with an ESI (+) ionization source. The method was validated following the AOAC criteria. The method detection limit was 0.15 - 4.20 µg/100g, the method quantitative limit was in the range of 0.5 - 14.0 µg/100g, the recovery range was 81.3 - 107.3%, the repeatability was in the range of 2.00 - 7.30 %, the reproducibility was 2.50 - 7.70%, which were in accordance with AOAC requirements. The method has been applied to analyze biotin content in 10 nutritional products and 10 supplements purchased in the market.