Quantitative analysis of vitamin K1 in fruits and vegetables by isotope dilution LC-MS/MS

摘要

A method has been developed for quantitative analysis of vitamin K1 in vegetables and fruits by LC-MS/MS. The method employed a neutral aluminum oxide column for sample clean-up. Considering matrix effects, an isotope standard (vitamin K1-D7) was added to correct matrix interferences, as well as pretreatment losses and instrument variability. Spiked recoveries in model matrices were 88.3a€“90.1% for spinach, 84a€“110% for lotus roots, and 108a€“115.6% for grapes. The relative standard deviations (RSDs) were 1.0a€“7.1% for intra-day and 2.8a€“8.8% for inter-day. The limit of detection (LOD) and limit of quantification (LOQ) were 0.001 mg kga?’1 and 0.004 mg kga?’1, respectively. The method is sensitive and reliable, which is successfully applied to different vegetable and fruit matrices. Vitamin K1 in fruit samples ranged from 0.008 mg kga?’1 to 0.401 mg kga?’1, and in vegetable samples from 0.0032 mg kga?’1 to 3.973 mg kga?’1.