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DL-Tartaric acid anhydrous, also called racemic tartaric acid, is a crystalline hydroxy dicarboxylic acid used in chemical synthesis, tartrate preparation and metal-complexing systems. Its combination of acidic and oxygen-containing coordination sites makes it useful where acidity and metal-ion interactions must be considered together. The carboxyl groups donate protons and form tartrate species, while carboxylate and hydroxyl groups can participate in coordination with suitable metal ions.
CAS No: 133-37-9
EC No: 205-105-7
Molecular formula: C4H6O6
Molecular weight: 150.09 g/mol
Appearance: white crystalline powder or crystals
Chemical class: hydroxy dicarboxylic acid
Stereochemical form: racemic mixture of L-(+) and D-(-) enantiomers
Water solubility: soluble
Thermal behavior: melting or decomposition around 200°C, method-dependent
WHAT IS DL-TARTARIC ACID ANHYDROUS?
DL-Tartaric acid anhydrous is the water-free form of racemic 2,3-dihydroxybutanedioic acid, CAS 133-37-9, used as an acid, complexing reagent and starting material for chemical preparations. It contains equal amounts of the L-(+) and D-(-) enantiomers and has the molecular formula C4H6O6.
Racemic acid combines two mirror-image molecular forms in a 1:1 ratio. Their optical rotations cancel in an ordinary solution measurement. This is compensation between enantiomers, not the internal symmetry responsible for the optical inactivity of meso-tartaric acid.
Anhydrous identifies the form without stoichiometric water of crystallization. It does not mean that every batch has exactly zero measurable moisture. Residual water, assay basis and drying history remain important when accurate solution preparation or reaction stoichiometry is required.
The acid is supplied in reagent and other commercially specified grades. Purity percentages, residual water, inorganic residue and optical-rotation limits depend on the actual specification. A supplier's grade description must not be inferred from the name alone.
Published synthesis routes include oxidation of maleate-derived starting materials through epoxysuccinic intermediates, followed by hydrolysis and separation of racemic and meso products. Such chemistry explains why control of stereochemical composition and residual process impurities matters. It does not establish the manufacturing route of every offered batch.
COMMON PRODUCT & CHEMICAL NAMES OF DL-TARTARIC ACID ANHYDROUS
DL-Tartaric acid anhydrous
DL-Tartaric acid
Racemic tartaric acid
Racemic acid
(±)-Tartaric acid
DL-2,3-Dihydroxybutanedioic acid
DL-Dihydroxysuccinic acid
Paratartaric acid
Uvic acid
The DL and racemic designations identify the equal-enantiomer composition. Anhydrous describes the hydration form rather than a different stereoisomer. The shorter name tartaric acid is ambiguous unless the isomer and hydration state are also specified.
Natural tartaric acid should not be used as an automatic synonym for the DL product. Commercial acid associated with wine-derived material is commonly the L-(+) form. Likewise, a tartrate is a salt or ester of tartaric acid, not necessarily the free acid described here.
CAS, EC AND CHEMICAL IDENTIFICATION OF DL-TARTARIC ACID ANHYDROUS
Product name: DL-Tartaric acid anhydrous
Chemical name: racemic 2,3-dihydroxybutanedioic acid
CAS No: 133-37-9
EC No: 205-105-7
Molecular formula: C4H6O6
Molar mass: 150.09 g/mol
Condensed structure: HOOC-CH(OH)-CH(OH)-COOH
Functional groups: two carboxylic acid groups and two hydroxyl groups
Main roles: acid reagent, tartrate precursor and complexing component
The identifiers distinguish the racemic acid from L-(+)-tartaric acid, CAS 87-69-4, D-(-)-tartaric acid, CAS 147-71-7, and meso-tartaric acid, CAS 147-73-9. Those stereochemical differences can affect crystal properties, solubility, biological suitability and the outcome of stereoselective chemistry.
Chemical identity alone does not establish a food, cosmetic or pharmaceutical grade. For the offered material, the specification and intended use must agree with the required stereoisomer and impurity profile. E334 is not assigned to the DL material on this page.
STRUCTURE AND STEREOCHEMISTRY OF DL-TARTARIC ACID ANHYDROUS
The four-carbon skeleton carries terminal carboxyl groups and adjacent hydroxyl-bearing stereocenters. Hydrogen bonding and polar oxygen groups contribute to its crystalline form and its interaction with water. In solution, protonation and metal binding depend on the chemical environment.
Tartaric acid has three distinct stereoisomeric forms: the two enantiomers and the meso form. A nominal count of four configurations reduces to three distinct stereoisomers because the two meso configurations describe the same internally symmetric molecule. The racemate is a mixture of the enantiomeric pair, not a fourth stereoisomer.
The L-(+) form corresponds to the (2R,3R) configuration, while D-(-) is its (2S,3S) counterpart. D/L notation and the sign of optical rotation describe different stereochemical conventions, even though those particular signs accompany these tartaric acid forms. They should not be generalized into a universal rule for other compounds.
HOW DOES DL-TARTARIC ACID ANHYDROUS WORK?
As a diprotic acid, racemic tartaric acid can donate two acidic protons per molecule during neutralization. Partially neutralized solutions contain hydrogen tartrate and other acid-base species according to pH. Further neutralization favors tartrate, with the counterion determined by the base used.
Oxygen donor sites can bind suitable metal ions and change their solution behavior. In a formulation, this can influence dissolved-metal availability, precipitation or a deposition process. Complexation depends on metal identity, pH, concentration and competing ligands rather than on the acid's presence alone.
Acidity and complexation should therefore be evaluated separately. A low pH does not prove strong binding of the target metal. Equally, a clear solution immediately after mixing does not prove long-term stability or compatibility with every substrate.
PHYSICAL AND CHEMICAL PROPERTIES OF DL-TARTARIC ACID ANHYDROUS
Representative profile:
Physical state: crystalline solid
Color: white to almost white
Water compatibility: soluble
Acid functionality: diprotic
Optical behavior: approximately zero net rotation for an equimolar racemate
Thermal region: approximately 198-212°C across reviewed supplier descriptions
Commercial assay examples: approximately 99-99.5%, grade-dependent
Thermal values vary with the grade, method and whether the observation is reported as melting or decomposition. One reviewed specification gives 200-206°C, while other supplier descriptions differ. The 168-170°C range commonly associated with L-(+)-tartaric acid should not be transferred to this DL product.
Purity by neutralization titration is not a complete stereochemical analysis. Other acidic components can influence the result, and low net rotation alone cannot exclude meso material. Use appropriate identity and composition methods when isomer control is important.
Water content must also be distinguished from assay. The anhydrous formula fixes the molar mass used for stoichiometry, while an actual batch may contain residual moisture. Confirm whether a reported purity is on the as-received or dry basis before calculating a precise dose.
Aqueous solutions are acidic, but there is no concentration-independent pH. Solubility values also need temperature, hydration form and a clear mass or volume basis. The typical descriptions above are not a binding sales specification.
DL-TARTARIC ACID ANHYDROUS IN COMPLEXATION AND MATERIALS RESEARCH
Documented laboratory applications include a complexing role in preparation of indium tin oxide powders, an additive role in bismuth electrodeposition, and use in polyaniline nanostructure research. Racemic acid has also been described as a weak-acid reagent in imidazolium ionic-liquid synthesis.
These are specific chemical applications, not proof that one concentration works across those processes. Metal ratios, solution pH, deposition conditions and reaction workup determine the result. A published material example does not qualify a supplied grade for electronic or high-purity use without relevant impurity data.
SECTORS AND INDUSTRIAL APPLICATIONS OF DL-TARTARIC ACID ANHYDROUS
Chemical synthesis and intermediate preparation
The free acid provides a defined organic-acid framework for preparing tartrate salts or derivatives. Reaction stoichiometry, counterion selection and stereochemical identity must be specified. Racemic feedstock cannot be treated as an enantiopure reagent.
Metal-containing process solutions
Acidification and tartrate complexation can be evaluated together in suitable aqueous systems. Useful observations include dissolved-metal concentration, precipitation, surface response and bath stability. Performance must be verified for the particular metal and operating conditions.
Functional-material development
Laboratory studies use racemic tartaric acid in selected oxide, electrodeposition and conductive-polymer systems. Here the purpose is to influence the chemical environment or material formation. Purity requirements can be more demanding than those of ordinary technical processing.
Industrial cleaning development
An acidic, complexing ingredient can be screened on an appropriate metal or mineral deposit system. Removal of the actual deposit and effects on the substrate must be measured separately. No universal corrosion protection or compatibility with acid-sensitive materials is implied.
FOOD AND PHARMACEUTICAL CONTEXT OF DL-TARTARIC ACID ANHYDROUS
In the EU food-additive framework, E334 identifies L-(+)-tartaric acid. It does not establish approval of the racemic DL product as the same additive. A food-grade claim in a supplier description must therefore be examined for the jurisdiction, exact substance and intended use rather than accepted as universal permission.
Likewise, a pharmaceutical tartrate name does not establish that racemic acid is the appropriate starting material. The required stereoisomer, grade and specifications depend on the preparation. This page makes no medicinal-use or dosage claim for the supplied acid.
PROBLEMS THAT DL-TARTARIC ACID ANHYDROUS CAN HELP ADDRESS
An aqueous process needing an organic acid may be assessed using controlled acid addition and measured pH or titratable acidity. Equal masses of different acids do not provide equal acid equivalents.
A metal-containing system prone to precipitation may benefit from evaluating a suitable tartrate ligand environment. The outcome depends on the metal and solution chemistry, and complexation is not a guarantee against every precipitate.
Inconsistent tartrate preparation can be reduced by distinguishing anhydrous feedstock from hydrated material and by correcting the dose for assay. This also avoids confusion between free acid, hydrogen tartrate and fully neutralized tartrate salts.
Stereochemical confusion is addressed by specifying DL explicitly. Shared formula and molar mass do not justify replacing an enantiopure acid with the racemate.
THINGS TO CONSIDER WHEN USING DL-TARTARIC ACID ANHYDROUS
Confirm the racemic identity and anhydrous form before weighing.
Use the batch assay and water basis for quantitative work.
Distinguish acid concentration from measured solution pH.
Account for both acidic protons in full neutralization calculations.
Evaluate the actual metal, competing ligands and counterions.
Avoid assigning food or pharmaceutical suitability from a generic acid name.
Check substrate compatibility and precipitation after storage.
Protect eyes and skin during powder handling and solution preparation. Acid-base mixing can generate heat, and acidic solutions can damage unsuitable surfaces. Provide controlled additions and an appropriate handling assessment.
INITIAL FORMULATION APPROACHES FOR DL-TARTARIC ACID ANHYDROUS
These proposed laboratory blends illustrate acidification and partial-neutralization trials. They are not validated commercial products, food recipes or medicinal preparations. All percentages are by weight of the complete initial blend, with the acid calculated nominally as anhydrous material of 100% assay for illustration.
EXAMPLE 1: DL-TARTARIC ACID ANHYDROUS IN AN ACIDIC CLEANING SCREEN
Components:
Anhydrous racemic tartaric acid: 2.00%
Compatible nonionic wetting agent, 100% active assumption: 0.20%
Demineralized water: 97.80%
Total: 100.00%
This is a small-scale screening liquid for a selected deposit and compatible test coupon. The concentration is an exploratory choice, not a universal cleaning dose. Identify the wetting agent and confirm that it remains compatible in the acidic solution.
Evaluation criteria:
Dissolution and clarity after preparation
pH and titratable acidity
Removal of a defined deposit under fixed contact conditions
Surface appearance and any measured material loss
Precipitation or color change after contact with the deposit
Do not use on acid-sensitive stone or untested metals. No commercial preservation or shelf-life claim is made.
EXAMPLE 2: DL-TARTARIC ACID ANHYDROUS IN A PARTIALLY NEUTRALIZED LIGAND SCREEN
Components:
Anhydrous racemic tartaric acid: 1.50%
Sodium hydroxide solution, 10.00% w/w: 4.00%
Demineralized water: 94.50%
Total: 100.00%
Per 100 g, the blend contains approximately 0.010 mol of acid and 0.010 mol of sodium hydroxide. That is approximately one hydroxide equivalent per acid molecule, not the two required for full neutralization. The solution is an acid-base distribution rather than a guaranteed pure hydrogen tartrate species.
Evaluation criteria:
Measured pH after mixing and cooling
Solution clarity and short-term stability
Comparison with the unneutralized acid at the same acid-equivalent basis
Compatibility in a separately designed metal-binding test
Precipitation after the intended change in water or temperature
Add the dilute base slowly to the acid solution with controlled mixing and cooling as required. A subsequent metal-salt addition needs its own mass balance and safety review.
ALTERNATIVES TO DL-TARTARIC ACID ANHYDROUS
L-(+)-tartaric acid retains the same formula and functional groups but has a different stereochemical identity. It is the relevant comparison where an enantiopure reagent or the EU E334 identity is required. Conversion of a recipe still needs a grade and performance review.
Citric acid offers another polycarboxylic acid framework with different acid equivalents and metal-binding behavior. Malic acid has two carboxyl groups and one hydroxyl group, so its structure is also different. Neither should replace racemic tartaric acid solely by matching weight or final pH.
Preformed sodium or potassium tartrate salts can reduce the need for in-process neutralization. Their counterion, hydration form and solution speciation differ from the free acid. Select alternatives by the required chemical function and verify them in the actual system.
QUALITY CONTROL AND PURCHASING CRITERIA FOR DL-TARTARIC ACID ANHYDROUS
Before comparing prices, define whether the use requires acidity, complexation, a derivative synthesis or stereochemical control. Specify the DL form, anhydrous basis and acceptable impurity profile. Appearance alone is insufficient to distinguish the acid from a related isomer or salt.
Information to review includes identity testing, assay method, residual water, optical rotation with test conditions and relevant isomer controls. Depending on the application, request inorganic residue, metals or other process-impurity limits. A titration value and a polarimetry result answer different questions.
The COA gives batch results, the TDS describes typical technical properties and the SDS communicates hazards and handling. Request documents for the exact offered grade. For unavailable values, intended-use confirmation, packaging and current supply terms, contact Ataman Kimya.
STORAGE AND HANDLING OF DL-TARTARIC ACID ANHYDROUS
Keep the solid in tightly closed, compatible packaging in a cool, dry, ventilated area. Prevent moisture ingress and avoid dust generation during transfer. Use clean equipment so that bases, metal residues or other contaminants are not introduced into the container.
Store away from incompatible reactive chemicals and strong oxidants. Keep bases segregated to prevent accidental neutralization. Obtain the offered grade's confirmed temperature range and shelf life from Ataman Kimya rather than assigning one supplier's conditions to all material.
Collect spills carefully without raising dust, prevent entry into drains and place the collected material in suitable waste containers. After long storage, check identity, moisture, caking and other relevant acceptance criteria before quantitative use. Caking alone neither proves chemical decomposition nor establishes that the material still passes specification.
SAFETY INFORMATION OF DL-TARTARIC ACID ANHYDROUS
Reviewed supplier grades include classification H318, causes serious eye damage. Some supplier classifications differ, so the current regional classification must be confirmed for the offered material through Ataman Kimya. The crystalline acid should not be handled as harmless simply because related tartaric acid forms occur in food.
Use chemical splash goggles, suitable gloves and protective clothing, with ventilation or dust control appropriate to the task. Avoid inhaling dust and prevent eye contact. Organic acid solids can burn under fire conditions, so control ignition sources and follow the workplace fire procedure.
For eye exposure, rinse immediately with plenty of clean water, remove contact lenses if easy and seek urgent medical attention. Wash contaminated skin, remove soiled clothing and seek help for persistent symptoms. After inhalation, move to fresh air and obtain medical assistance if unwell.
Prevent uncontrolled environmental release and dispose of material according to the applicable local requirements. No unverified transport classification or UN number is assigned here. Contact Ataman Kimya for the current shipment information and regional safety documentation.
SUPPLY OF DL-TARTARIC ACID ANHYDROUS FROM ATAMAN KIMYA
ATAMAN KİMYA can be contacted for DL-Tartaric acid anhydrous supply inquiries. Confirm the available grade, specification, package size and supporting documentation for the intended application.
Include the required quantity, delivery destination, assay and water limits, relevant impurity requirements and whether stereochemical composition needs specific verification. State the intended use clearly so that a generic tartaric acid offer is not confused with the required racemic anhydrous product.
FREQUENTLY ASKED QUESTIONS ABOUT DL-TARTARIC ACID ANHYDROUS
What is this product?
The anhydrous racemic form of 2,3-dihydroxybutanedioic acid.
What is its CAS number?
133-37-9.
What is its EC number?
205-105-7.
What are the formula and molar mass?
C4H6O6 and 150.09 g/mol on the anhydrous basis.
What does DL mean?
Equal amounts of the L-(+) and D-(-) enantiomers.
Is the racemate the same as meso-tartaric acid?
No, the racemate is an enantiomeric mixture, while the meso form is a distinct internally symmetric stereoisomer.
Why is the racemate optically inactive?
The rotations of the two enantiomers cancel in the mixture.
Does anhydrous guarantee zero moisture?
No, residual water still depends on the batch specification and storage.
Can the L-form melting range be used for the DL acid?
No, the forms have different thermal behavior.
Is it soluble in water?
Yes, but a quantitative solubility needs defined conditions and the correct form.
Is titration alone enough to prove stereochemical identity?
No, titration measures acid equivalents rather than a full isomer distribution.
Does near-zero rotation exclude meso material?
No, meso-tartaric acid is also optically inactive.
Is E334 assigned to this DL product?
No, the EU E334 identity is L-(+)-tartaric acid.
Can it replace an enantiopure resolving acid?
Not automatically, the racemate does not provide the same single-enantiomer reagent.
What is its role in a metal-containing solution?
It can provide acidity and a tartrate complexing environment, depending on pH and the metal.
Does one equivalent of base fully neutralize it?
No, full neutralization of the diprotic acid requires two base equivalents.
Is the material hazardous to the eyes?
Yes, reviewed grades include a serious-eye-damage classification and require protective handling.
What should be requested before buying?
The exact DL anhydrous specification, batch COA, current SDS and documents relevant to the intended application.
DL-TARTARIC ACID ANHYDROUS - TECHNICAL SUMMARY
DL-Tartaric acid anhydrous is racemic 2,3-dihydroxybutanedioic acid, identified by CAS 133-37-9 and EC 205-105-7. Its anhydrous formula is C4H6O6 and its molar mass is 150.09 g/mol.
The 1:1 mixture of L-(+) and D-(-) molecules is optically inactive through cancellation between enantiomers. It remains distinct from meso-tartaric acid and from either enantiopure form.
Acidity, tartrate formation and oxygen-donor coordination support chemical synthesis and selected metal or materials applications. Performance depends on pH, concentration, counterions and the complete process.
Anhydrous form, residual water and assay basis matter for weighing and neutralization. Neither acid titration nor optical rotation alone provides complete proof of purity and stereochemical composition.
The EU E334 identity must not be transferred from L-(+)-tartaric acid to the DL product. Grade selection also requires attention to eye hazards, storage and the offered material's current documentation.
DL-Tartaric acid anhydrous can be sourced from ATAMAN KİMYA. For further information and supply inquiries about DL-Tartaric acid anhydrous, please contact ATAMAN KİMYA.
