Background: B vitamins are a group of water-soluble vitamins which have an important
role in cell metabolism and, therefore, they are regularly added to foods and beverages. Determination
of vitamins in these products for quality control purposes is of interest. However, due to the
complex matrixes of foods and beverages, one or more pretreatment steps are usually used to increase
sensitivity and selectivity of the available instruments. The goal of sample preparation is sample
cleanup, sample enrichment, and signal enhancement.
Methods: In the present study, MEPS have been used for extraction of B vitamins (B1, B2, B3, B5
and B6) from energy beverage matrixes prior to liquid chromatography-electrospray ionization tandem
mass spectrometry assay. Various important factors affecting MEPS performance including the
type of sorbent, type of preconditioning and washing solvent, type and volume of eluent, sample and
eluent ow rates were optimized.
Results: Under the optimized condition, five linear calibration curves in the concentration range of
1-300 ! g mL-1 were obtained. The repeatability and accuracy of the method were evaluated by determination
of three quality control samples using the developed method, and the results (coefficients
of variation (CV%) values were between 1% and 14%, relative recoveries ranged between 86-119%)
confirm that a powerful alternative method has been developed for the extraction and determination
of the investigated vitamins in energy beverage matrixes. MEPS sorbent was used for 100 extractions
before it was discarded.
Conclusions: In summary, MEPS can be used as a powerful sample preparation technique prior to
liquid chromatography-electrospray ionization tandem mass spectrometry assay for daily quality
control analysis of B vitamins in energy drinks as a cheap, fast, simple, and at the same time accurate
and precise method.