Detecting Vitamin C at Tiny Levels with a Special Enzyme Test

Jim Crocker
22nd May, 2024

Detecting Vitamin C at Tiny Levels with a Special Enzyme Test

Image Source: Natural Science News, 2024

Key Findings

  • A study by Prince of Songkla University introduced a new, simple method to detect vitamin C with higher sensitivity than existing techniques
  • This method uses the inhibitory effect of vitamin C on horseradish peroxidase and hydrogen peroxide, observed through color changes in a specific substrate
  • The new method is highly accurate and reliable, with minimal interference from common substances, making it suitable for various applications, including clinical diagnostics and quality control
Ascorbic acid, also known as vitamin C, is a vital nutrient involved in numerous bodily functions, including immune response and connective tissue maintenance. Traditionally, detecting ascorbic acid levels has relied on various colorimetric methods. A recent study by Prince of Songkla University introduces a novel, one-step method for detecting ascorbic acid that promises higher sensitivity and simplicity compared to existing techniques[1]. This new method leverages the inhibitory effect of ascorbic acid on horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The reaction is observed through colorimetric changes in 3,3',5,5' tetramethylbenzidine (TMB), a substrate that changes color in the presence of HRP and H2O2. This method has been optimized for high linearity (r2 = 0.9999), with detection and quantification levels at 1.35 nM and 4.08 nM, respectively. These levels are significantly more sensitive than the High-Performance Liquid Chromatography (HPLC) method, which has a detection threshold of 11 μM. The study found that both intra- and inter-assays showed high correlations at different ascorbic acid concentrations (r2 > 0.9999). This method was also tested on vitamin C tablets, ascorbate salts, fruits, and various market products, yielding similar results (r2 = 0.999). Importantly, common interfering substances such as citric acid, lactic acid, tartaric acids, and glucose had negligible effects, with high recoveries (>98%) across a range of concentrations (1 mg/mL to 0.0078 mg/mL). The recovery error (RE%) was less than 10%, underscoring the method's accuracy and reliability. The significance of ascorbic acid in various biological roles is well-documented. For instance, it counteracts oxidative stress and participates in collagen synthesis, which is crucial for skin health[2]. Its antioxidant properties help in reducing oxidative damage, potentially lowering cancer risk[3]. Ascorbic acid also plays a role in collagen metabolism, which is integral to maintaining skin structure and preventing aging[4]. The new detection method could therefore have wide-ranging applications, from clinical diagnostics to quality control in the food and pharmaceutical industries. The ability to detect ascorbic acid at such low concentrations with high accuracy and minimal interference is a significant advancement. Traditional methods like HPLC, while accurate, are complex and less sensitive. The simplicity and reproducibility of this new method make it a promising tool for point-of-use testing, enabling more accessible and frequent monitoring of ascorbic acid levels. In summary, the study from Prince of Songkla University presents a groundbreaking method for ascorbic acid detection that outperforms traditional techniques in sensitivity, simplicity, and reliability. This advancement not only enhances our ability to monitor this essential nutrient but also opens up new possibilities for its application in various fields.

MedicineBiochemPlant Science


Main Study

1) Nanolevel of detection of ascorbic acid using horse-radish peroxidase inhibition assay.

Published 30th May, 2024 (future Journal edition)

Related Studies

2) Biological role of vitamin C in keratinocytes.

Journal: Nutrition reviews, Issue: Vol 63, Issue 3, Mar 2005

3) Ascorbic acid metabolism and functions: A comparison of plants and mammals.

4) Ascorbic Acid (Vitamin C) as a Cosmeceutical to Increase Dermal Collagen for Skin Antiaging Purposes: Emerging Combination Therapies.

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