Dehydroascorbic Acid (DHA) Content Assay Kit (Phenanthroline, Colorimetric Method)

Cat. No.: D1521842

GRADE & PURITY BioReagent

Overview

Vitamin C, also known as L-Ascorbic Acid (AsA) , is an essential nutrient for higher primates and a few other organisms. In living organisms, Vitamin C acts as an antioxidant; it is an acidic hexose derivative and a lactone of an enolic sugar acid, protecting the body from damage by free radicals. It also functions as a coenzyme. Its widespread dietary sources are various fresh fruits and vegetables. Vitamin C has two isomers, the L-form and the D-form, but only the L-form possesses physiological function. Both the reduced and oxidized forms exhibit physiological activity. The detection principle of this kit is as follows: A reducing agent is used to convert dehydroascorbic acid to reduced ascorbic acid. Under acidic conditions, the reduced ascorbic acid reduces ferric ions (Fe³⁺) to ferrous ions (Fe²⁺), which then form a stable red chelate complex with phenanthroline. The absorbance is measured at 534 nm using a spectrophotometer. Within a specific concentration range (sample concentration controlled between 1-40 μg/ml), the absorbance shows a linear relationship with the ascorbic acid content, allowing for the determination of ascorbic acid concentration. This kit is primarily used for detecting Vitamin C (ascorbic acid) in plant tissues. It measures the total ascorbic acid content; by subtracting the original reduced ascorbic acid content present in the sample, the dehydroascorbic acid content can be obtained. The advantages of this method are: 1. Stable reaction with minimal fading; 2. Simple operation; 3. No interference from reducing sugars or other common reducing substances, ensuring good specificity; 4. High sensitivity. This product is for research use only and is not intended for use in diagnostic procedures.

Specifications

Specifications & Purity

BioReagent

Grade

BioReagent

Application

Cell Metabolism

Method Of Detection

Colorimetric Method

Detection instrument

Visible Spectrophotometer

Detection wavelength

534nm

Storage and Shipping

Storage

Store at 2-8°C,Protected from light

Shipped In

Wet ice

Stability And Storage

Store at 2-8℃ for 6 months. Store in the dark.

Application Protocols

Follow the official kit booklet for exact steps, reagent identities, and volumes. The outline below reflects a common literature-based workflow for DHA quantification via phenanthroline colorimetry and is provided for context only.

General workflow (literature/guidance):

1. Sample preparation

• Extract samples rapidly in cold, light-protected, compatible buffer to preserve AA/DHA. Clarify by centrifugation/filtration.

2. Calibration

• Prepare fresh AA standards spanning the expected range; include a reagent blank.

3. Native AA measurement

• Combine sample/standards with phenanthroline/Fe(III) working solution under prescribed conditions. Incubate to develop color; read A510.

4. Total AA measurement (DHA → AA conversion)

• Treat an aliquot of the same sample with a selective reducing reagent to convert DHA to AA (conditions vary by method), then proceed with colorimetric development and read A510.

5. Calculations

• Determine AA from the calibration curve for both native and total measurements. Compute DHA = (Total AA) − (Native AA), applying dilution factors and blank subtraction.

6. QC and validation

• Include duplicate/triplicate wells, QC controls of known AA/DHA ratios, and verify linearity and recovery via spike-in.

Important: Exact reagent compositions, incubation times, volumes, and wavelength settings for this item are not specified here; refer to the kit insert/CoA. For research use only.

Biological Roles

Context (literature): Dehydroascorbic acid (DHA) is the oxidized form of vitamin C. Together, DHA and ascorbic acid (AA) constitute a redox couple central to antioxidant defense in biological systems.

• Redox cycling: AA donates electrons to neutralize reactive oxygen species and is converted to DHA, which can be recycled back to AA by cellular reductants (e.g., glutathione-dependent systems, thioredoxin, and enzymes such as dehydroascorbate reductase in plants and some microbes).
• Transport: While AA is transported by SVCT (sodium-dependent vitamin C transporters), DHA can enter cells via GLUT family facilitative glucose transporters due to structural similarity to glucose in its open-chain hydrated forms (literature).
• Compartmentalization: The AA/DHA ratio reflects cellular redox status, with high AA pools in cytosol, mitochondria, and lumen of the endoplasmic reticulum participating in redox homeostasis.
• Stability: DHA is chemically labile, tending toward hydrolysis to 2,3-diketogulonic acid under neutral/alkaline conditions; thus, accurate measurement requires careful, rapid handling.
• Physiological relevance: The AA/DHA couple supports enzymatic cofactor regeneration, collagen hydroxylation pathways (via maintaining Fe2+), and general oxidative stress management. Changes in the AA:DHA ratio can indicate oxidative shifts in experimental models.

This kit facilitates research quantification of DHA within that biochemical framework. No medical or clinical claims are made; for research use only.

Buffer Applications

This product is an analytical assay kit rather than a buffering system. It does not provide a defined buffer for general laboratory pH control.

• Applicability: Not typically used to prepare or maintain buffer pH for biochemical reactions. Any buffers included are intended solely to support the assay chemistry.
• Guidance: For pH control in your workflows, select buffers suitable for your target pH range (e.g., phosphate, acetate, HEPES; literature) and verify compatibility with the phenanthroline assay, particularly regarding metal chelation and redox activity. Avoid strong chelators (e.g., EDTA) during the color development step, as they can interfere with Fe complexation.

For detailed composition of any kit-provided buffers, refer to the CoA/Spec Sheet and the kit protocol.

Green Alternatives

Greenness considerations for DHA/AA colorimetry focus on minimizing hazardous reagents, solvent use, and waste while maintaining analytical performance.

• Current chemistry (literature): 1,10-Phenanthroline complexation with Fe(II) in aqueous media is generally water-based and uses modest reagent quantities. The main concerns are transition-metal salts and organic chelator disposal.

Potential alternatives and trade-offs (literature/general):

| Approach | Green advantage | Trade-offs | | --- | --- | --- | | DCPIP redox assay (2,6-dichlorophenolindophenol) | Aqueous, rapid, minimal metals | Dye toxicity/halogenated dye; specificity can be lower; spectral overlap in colored matrices | | Enzymatic assays (ascorbate oxidase) | High specificity, mild conditions | Enzyme cost, stability, and potential matrix inhibition | | HPLC-UV or HPLC-ECD | Low per-sample waste with microbore; high specificity | Organic mobile phases and acetonitrile use; instrument energy footprint | | Microplate miniaturization of phenanthroline | Reduces reagent and waste volumes | Requires validated microplate protocol and pathlength correction |

Practical greener practices:

• Use 96- or 384-well plates to reduce volumes, and collect waste in dedicated metal-containing streams.
• Prepare only the required amount of working reagent to reduce disposal.
• Where compatible, substitute lower-hazard acids/buffers and avoid excess chelators.

Note: Any procedural change must be validated against the kit’s official protocol to ensure accuracy and precision.

Pharmaceutical Uses

Research/formulation context (no therapeutic claims):

• Use case: Quantification of ascorbate redox state (AA vs DHA) in research and development settings, such as assessing stability of vitamin C in topical, oral, or parenteral prototype formulations and in excipient compatibility studies.
• Process development: Monitoring oxidative degradation pathways of ascorbate under accelerated conditions (temperature, light, oxygen) and evaluating the impact of antioxidants, chelators, and packaging on DHA formation (research/QA in development labs).
• Raw material QC (research): Screening incoming excipients for trace metal contamination or redox activity indirectly by observing impacts on ascorbate stability in spiking studies.

Practical notes:

• Validate matrix compatibility: Preservatives, flavors, colorants, and high ionic strength can affect baseline absorbance and Fe–phenanthroline complex formation; use matrix-matched calibration or standard addition where appropriate.
• Sample preparation: Cold, acidified aqueous extracts can help preserve the native AA/DHA ratio (literature). Filtration or centrifugation minimizes turbidity.
• Documentation: For regulated settings, develop and document method performance characteristics (linearity, LOD/LOQ, precision, accuracy, robustness) using the kit procedure as a foundation.

All uses are for research purposes only. This kit is not approved for clinical diagnostics, release testing under pharmacopeial monographs, or medical decision-making.

Physical Properties

This is a multi-component assay kit. Conventional single-compound physical constants are not directly applicable.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Physical state of components (buffers, standards, reagents): Not specified for this item; refer to CoA/Spec Sheet.
• Density, melting/boiling points, refractive index, pKa, logP: Not applicable to the kit as a whole.
• Solubility: Reagents are typically supplied in aqueous solutions or lyophilized forms for aqueous reconstitution (literature, general for colorimetric kits). Exact details are not specified for this item; refer to CoA/Spec Sheet.
• Detection wavelength (literature): The Fe(II)–1,10-phenanthroline complex exhibits a strong absorbance band near 510–520 nm (commonly ~510 nm). This is literature information and not a specification for this item.
• Working temperature (literature): Many phenanthroline colorimetric reactions proceed efficiently at ambient temperature; exact incubation times/temperatures are protocol-dependent and not specified for this item.

Note: For any quantitative assay, follow the kit’s provided calibration range, pathlength assumptions, and plate/cuvette geometry as stated in the official protocol. Where values are not listed above, they are not specified for this item; refer to CoA/Spec Sheet.

Quality & Grades

• Stated grade/purity: BioReagent

What BioReagent grade generally implies (context for this kit):

• Components are suitable for biochemical assays and routine laboratory research, with attention to background absorbance and contaminant levels that could interfere with colorimetric detection (literature/general).
• While not equivalent to clinical diagnostics grade, BioReagent kits are formulated for reliable performance in research workflows. Lot-to-lot consistency is typically supported by internal QC metrics such as linearity of standard curves and signal-to-blank performance (details not specified for this item).

Item-specific quality details:

• Performance specifications (e.g., detection range, LOD/LOQ, intra/inter-assay precision), stabilizers, and extinction coefficients: Not specified for this item; refer to CoA/Spec Sheet.
• UV cutoffs, trace metal levels, and peroxide content: Not specified for this item.

Practical guidance:

• Use the provided standard (if included) to generate a fresh calibration curve for each run to confirm linearity and sensitivity.
• Follow the recommended incubation times and temperatures in the official protocol to ensure consistent chromophore development and minimize drift.
• Record the lot number and retain CoA/SDS documents with your data package for traceability.

Reaction & Applications

Analytical principle (literature):

• L-ascorbic acid (AA) reduces Fe(III) to Fe(II), which forms a strongly colored [Fe(phen)3]2+ complex with 1,10-phenanthroline, exhibiting an absorbance band around 510 nm. To quantify DHA, samples are treated in two ways: (1) native AA measurement, and (2) total AA after converting DHA → AA using a selective reducing step. DHA content is then calculated by difference.

Typical applications (research use only):

• Quantifying vitamin C redox state (AA vs DHA) in cell/tissue lysates, plant materials, and food matrices.
• Monitoring oxidative stress responses and redox cycling in biochemical experiments.
• Stability testing of ascorbate-containing formulations during process development and storage (R&D/QA in research settings).

Practical tips (general):

• Work cold and protected from light during extraction to minimize AA oxidation and DHA degradation.
• Avoid metal chelators or adjust protocols accordingly; chelators can depress signal.
• Use freshly prepared calibration standards matched to the assay matrix when possible to correct for matrix effects.
• Clarify samples to minimize turbidity; use matched blanks to correct background absorbance.

Data handling:

• Verify linearity of the standard curve each run; use appropriate regression (often linear through origin or standard linear fit depending on protocol).
• Run duplicates/triplicates and include QC samples of known AA/DHA ratios to track assay performance over time.

Note: Exact reagents, times, and calculations should follow the manufacturer’s protocol for this item.

Reaction Conditions

Because this is an assay kit, definitive conditions must follow the manufacturer’s protocol. The following parameters are provided as general literature guidance for phenanthroline colorimetry of ascorbate and should not be taken as item-specific specifications.

• Detection wavelength (literature): ~510 nm for the Fe(II)–1,10-phenanthroline complex.
• Medium: Aqueous buffer at controlled pH; avoid strong chelators that bind Fe(II/III).
• Temperature: Ambient conditions are commonly used; consistent temperature improves reproducibility.
• Incubation time: Color development typically stabilizes within 5–30 minutes depending on reagent concentrations and pH.
• Stoichiometry: Excess phenanthroline relative to Fe(II) drives formation of the intensely colored tris-complex.
• Order of addition: Fe(III) and phenanthroline are combined with sample under conditions where AA reduces Fe(III) to Fe(II). For DHA determination, a reduction step converts DHA → AA before the colorimetric phase; native AA is measured in parallel.
• Calibration: Prepare fresh standards over the expected concentration range; measure blank and standards under identical conditions for baseline correction.
• Interferences: Metal chelators (EDTA, citrate at high levels), strong oxidants/reductants, and colored/turbid matrices can bias results; mitigate by sample cleanup, blanks, and matrix-matched curves.

Exact reagent concentrations, pH, and timings are not specified for this item; refer to the kit insert/CoA for authoritative instructions.

Safety & Handling

• GHS classification, signal word, pictograms, and H-statements: Not specified for this item; refer to the SDS for each kit component.
• General hazards (literature): 1,10-Phenanthroline chelates transition metals; iron salts may be irritants; reducing agents and acids/buffers may be corrosive or cause irritation depending on concentration. Treat all reagents as potentially hazardous.

Best-practice PPE and engineering controls:

• Wear lab coat, safety glasses, and nitrile gloves. Work in a well-ventilated area or fume hood when handling concentrated reagents, acids, or reducing agents.
• Avoid inhalation, ingestion, and skin/eye contact. Do not pipette by mouth. Wash hands after use.

Handling and incompatibilities (general):

• Protect phenanthroline-containing reagents from strong oxidizers and avoid contact with reactive metals in concentrated form.
• Keep iron-containing and reducing reagents separate from incompatible materials; avoid contamination with chelators (EDTA) that can sequester iron and affect assay response.
• Light sensitivity: Follow the product guidance to keep reagents protected from light, consistent with kit storage instructions.

First aid (summary; defer to SDS):

• Skin/eye contact: Rinse with copious water for ≥15 min; remove contaminated clothing; seek medical advice.
• Inhalation: Move to fresh air; seek medical attention if symptoms occur.
• Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.

Waste: Collect aqueous metal-containing waste and organic dye solutions according to institutional and local regulations.

Solvent Selection

This is an aqueous colorimetric assay kit. Conventional organic solvent selection is not typically applicable. However, sample extraction and dilution media can strongly influence results.

• Assay medium (general): Reactions for Fe–phenanthroline complexes are typically run in aqueous buffers at controlled pH (literature). Exact buffer composition for this item is not specified; refer to the kit protocol.
• Miscibility: The colorimetric readout is optimized for water-based matrices. High proportions of organic solvents (e.g., ethanol, methanol, acetonitrile) may change complex stability or baseline absorbance.
• Matrix considerations (practical):
  • Avoid strong chelators (EDTA, citrate at high levels) that can sequester Fe and suppress color formation.
  • Minimize strong reducing agents (e.g., DTT, TCEP) or oxidants in samples unless prescribed by the protocol phase, as they can elevate background or consume Fe(III).
  • Clarify turbid samples (centrifugation/filtration) to reduce light scattering.
• Alternative extraction approaches (literature/guidance): For foods or plant tissues rich in ascorbate, cold aqueous acidified extractions (e.g., with dilute metaphosphoric or acetic acid) can stabilize AA/DHA equilibria and reduce enzymatic oxidation; compatibility must be validated with the kit protocol.

Small comparison (literature):

• Aqueous buffer: highest compatibility with colorimetric complexation.
• 10–20% alcohols: may be tolerable but require blank matching.

• 30% organic solvent: often detrimental to complex formation and baseline; validate empirically.

Storage & Reconstitution

• Storage conditions (as provided): Store at 2–8°C, protected from light.
• Shipping: Shipped on wet ice.
• Stability: Shelf-life and post-opening stability are not specified for this item; refer to CoA/Spec Sheet.

General guidance (applicable best practices):

• Keep all light-sensitive reagents in amber vials or wrapped in foil; minimize exposure during handling.
• Allow refrigerated components to equilibrate to room temperature before opening to reduce condensation, then promptly return to 2–8°C after use.
• If any components are supplied lyophilized, reconstitute with the specified solvent/volume from the kit booklet and mix gently to avoid foaming. Exact reconstitution details are not specified for this item.
• Avoid repeated freeze–thaw cycles unless the protocol explicitly supports freezing; aliquot working solutions where permitted by the kit instructions.
• Do not use beyond the expiration date; monitor for precipitation, discoloration, or unexpected background increases as signs of reagent degradation.

Where a particular concentration, diluent, or stabilizer is required, it is not specified for this item; consult the kit insert/CoA. Use only as directed and for research use only.

Structure & Identity

This product is an assay kit, not a single small-molecule substance. It is designed to quantify dehydroascorbic acid (DHA) via a phenanthroline-based colorimetric readout.

• Item type: Analytical assay kit (colorimetric, phenanthroline chemistry)
• Analyte(s): Dehydroascorbic acid (DHA), typically determined by converting DHA to L-ascorbic acid (AA) and measuring AA colorimetrically (literature principle)
• Kit components: Not specified for this item; refer to CoA/Spec Sheet.
• CAS, CID, InChIKey, SMILES: Not applicable to the kit as a whole; individual reagents not specified for this item.
• Molecular formula and molecular weight: Not applicable to the kit; analyte (DHA) is the oxidized form of vitamin C (literature), but no single identifier represents the entire kit.

Structural features (literature context):

• DHA is the oxidized diketone/lactone counterpart of L-ascorbic acid, lacking the enediol that confers strong reducing power to AA.
• In aqueous systems, DHA exists in equilibria with hemiketal and hydrated forms; it is labile and can degrade to diketogulonic acid.

2D-structure description of the chemistry (literature):

• The colorimetric readout relies on the formation of an Fe(II)–1,10-phenanthroline tris-chelate (orange-red complex) after AA reduces Fe(III) to Fe(II). DHA is first reduced to AA by a selective reducing treatment; the difference between total AA (after reduction) and native AA gives DHA.

Important: Exact reagent identities, concentrations, and any stabilizers are not specified for this item; consult the kit insert/CoA.

Synthetic Utility

This product is an analytical assay kit and is not typically employed as a reagent for synthetic transformations.

• Not applicable: It does not serve as a building block, catalyst, or stoichiometric reagent in organic synthesis.

However, the underlying chemistry offers conceptual relevance (literature/general):

• The Fe(III) → Fe(II) reduction by ascorbate exemplifies single-electron transfer under mild aqueous conditions, followed by strong N-donor chelation of Fe(II) by 1,10-phenanthroline to form [Fe(phen)3]2+.
• Such coordination chemistry underpins numerous redox indicators and metal–ligand probes used to track electron-transfer events in reaction development and mechanistic studies.
• The AA/DHA interconversion highlights redox buffering concepts relevant to designing protecting-group strategies or redox-compatible processes in bio-inspired synthesis.

If you require reagents for synthetic applications (e.g., phenanthroline ligands as catalysts or iron salts as promoters), consider sourcing those as standalone chemicals with appropriate grades/specifications. For analytical quantification of ascorbate species during synthesis or process development, this kit can support research monitoring, but it is not a synthetic reagent per se.

Target Specificity

This product is not an antibody or affinity reagent and does not target a biological macromolecule via epitope recognition.

• Assay target (analytical): Dehydroascorbic acid (DHA), quantified indirectly by reduction to L-ascorbic acid (AA) and subsequent phenanthroline-based colorimetric detection (literature principle).
• Specificity considerations (general): Selectivity arises from the reducing capacity of AA toward Fe(III) under the assay’s controlled conditions and the highly absorbing Fe(II)–phenanthroline complex. Sample components that reduce Fe(III) or chelate Fe can interfere; specificity is maintained by appropriate blanks, differential measurement (native vs reduced), and sample preparation.

No clone, isotype, species reactivity, or epitope information is applicable to this kit.