Determination of Vitamin C (Ascorbic Acid) Using High Performance Liquid Chromatography Coupled with Electrochemical Detection

Abstract

Vitamin C (ascorbic acid, ascorbate, AA) is a water soluble organic compound that participates in many biological processes. The main aim of this paper was to utilize two electrochemical detectors (amperometric – Coulouchem III and coulometric – CoulArray) coupled with flow injection analysis for the detection of ascorbic acid. Primarily, we optimized the experimental conditions. The optimized conditions were as follows: detector potential 100 mV, temperature 25 °C, mobile phase 0.09% TFA:ACN, 3:97 (v/v) and flow rate 0.13 mL·min-1. The tangents of the calibration curves were 0.3788 for the coulometric method and 0.0136 for the amperometric one. The tangent of the calibration curve measured by the coulometric detector was almost 30 times higher than the tangent measured by the amperometric detector. Consequently, we coupled a CoulArray electrochemical detector with high performance liquid chromatography and estimated the detection limit for AA as 90 nM (450 fmol per 5 μL injection). The method was used for the determination of vitamin C in a pharmaceutical preparations (98 ± 2 mg per tablet), in oranges (Citrus aurantium) (varied from 30 to 56 mg/100 g fresh weight), in apples (Malus sp.) (varied from 11 to 19 mg/100 g fresh weight), and in human blood serum (varied from 38 to 78 μM). The recoveries were also determined.

Microbiological and chemical quality assessment of some commercially packed fruit juices sold in Nigeria

“…The values reported for percentage total soluble solid could be associated to high fructose corn syrup (HFCS) often used as sweetening agent by some manufacturer. The level of Ascorbic acid reported is within standard specification and in agreement with the reports of Malo et al (2006), Gazdik et al (2008) and Okiei et al (2009). The detection of Benzoic acid in samples NDAN, NCHP, IRUB and IARI even though within accepted standard specification could be a deliberate attempt of the manufacturers at deceiving the consumer with claims of natural product free of any preservative.…”

Routine sample preparation and HPLC analysis for ascorbic acid (vitamin C) determination in wheat plants andArabidopsisleaf tissues

“…In leaves of Arabidopsis thaliana the ascorbate concentration is about 5 μmol g -1 FW (15), but this value depends on the type of tissue, plant age, the time of day when samples were taken, and light intensity (13). In the present case the total AA level of the Arabidopsis seedlings was less than 1 μmol g -1 FW, but this was extracted from young seedlings grown at relatively low light intensity.…”

“…AA appears to be universal in photosynthetic eukaryotes, occurring in the cytosol, chloroplasts, vacuoles, mitochondria and cell wall (33). FW in Arabidopsis (3), but these values depend on tissue type, plant age, time of day at sampling, and light intensity (13). In certain alpine plants, ascorbate leaf concentration reach 45 μmol g -1 FW (35), and the chloroplasts of alpine plants have been reported to contain up to 10 times the amount of ascorbate found in lowland plants (36).…”

Potensi Bayam Merah (Amaranthus tricolor L) sebagai Antioksidan pada Toksisitas Timbal yang Diinduksi pada Mencit

“…15 Betalain dan vitamin C selain sebagai antioksidan, juga diduga memiliki kemampuan sebagai chelator melalui kemampuannya membentuk kompleks ion yang larut air dan juga mampu membentuk kompleks dengan logam sehingga kemungkinan kadar timbal darah dan jaringan juga dapat diturunkan melalui mekanisme tersebut. [16][17][18] Vitamin C diketahui dapat menghambat ambilan timbal di tingkat seluler dan juga menghambat sitotoksisitas timbal. 19 Hal ini tampak dalam hasil yang diperoleh dalam penelitian ini bahwa kadar SOD kelompok mencit yang diberikan timbal asetat tanpa jus bayam merah (K 1 ) lebih rendah dibanding dengan kelompok mencit yang diberikan timbal asetat kemudian diberikan jus bayam merah (K 2 ).…”