Rapid determination of L-ascorbic acid content in vitamin C serums by ultra-high-performance liquid...

This study aimed to develop and validate a rapid, simple, accurate and precise analytical method for the quantification of L-AA in vitamin C serums. Moreover, the developed method was further applied to determine L-AA in eight different brands of vitamin C serums. A complementary study was also carried out to evaluate the stability of L-AA in the vitamin C serum samples after 15, 30, 45 and 60 days of storage at ambient temperature (15-35°C).

Ultra-high-performance liquid chromatography-tandem mass spectrometry was applied.

Quantitative analyses were performed with a total chromatographic run time of 1.5 min by matrix-matched calibration, and the analytical curve was linear over the range of 1-1700 µg L^-1 with a correlation coefficient of 0.9998. The limits of detection (LOD) and quantification (LOQ) were 0.3 and 1.0 µg L^-1 , respectively. Intra- and inter-assay precisions, expressed in terms of relative standard deviation, ranged from 0.3% and 2.2%, respectively, and recoveries in concentration levels of 1 and 5 µg L^-1 were 103.9% and 101.2%, respectively. The proposed analytical method was successfully applied to determine the L-AA content in eight commercial vitamin C serum samples. The stability of the target analyte in samples stored at ambient temperature (15-35°C) was evaluated throughout 60 days with a 15-day interval between analyses. At 0 days, L-AA content in samples ranged from 1.05 to 169.91 mg L^-1 , which decreases over time.

The proposed method could be powerful in routine analyses to ensure the quantification of L-AA in vitamin C serums since it proved to be a simple, reliable, fast, precise, accurate and sensitive analytical method.