What is the regulatory status of PQQ disodium salt?

It differs by market and is the importer's responsibility. PQQ disodium salt holds a GRAS notice in the United States for specified beverage categories, and was approved in China as a new food raw material in 2023. We supply the ingredient and its documentation; we do not advise on market access.

Why is PQQ disodium salt red-brown?

PQQ is a quinone; the conjugated ring system absorbs in the visible range, so the colour is inherent to the molecule. Consistency batch to batch is what matters, which is why the specification carries a reference colour description.

What is the minimum order quantity and lead time?

Evaluation samples start at 1 g. Lead time for commercial quantities is confirmed in writing once specification, quantity and destination are agreed.

Can you supply a PQQ grade for beverages?

The disodium salt is the beverage-compatible form; a milled grade with a tighter particle-size distribution can be quoted where a blending line requires it. Two formulation constraints should be tested before scale-up: the red-brown colour carries into the finished drink, and stability in aqueous solution is limited by light and oxygen.

Fermented actives · Coenzyme

PQQ (Pyrroloquinoline Quinone Disodium Salt)

Q: What does 98% refer to — the salt or the free acid?

On our COA the basis is stated explicitly. This matters more than the number: 98.0% disodium salt is about 86.5% PQQ on a free-acid basis, using the molecular weights 374.17 and 330.21. A percentage quoted without a basis cannot be compared across suppliers.

Q: How should PQQ disodium salt be stored?

Sealed at 2–8 °C, protected from light and moisture. The material is hygroscopic, so let the container reach room temperature before opening; condensation onto the powder is the most common cause of a good lot degrading.

A fermentation-derived redox cofactor, supplied as a red-brown crystalline powder at ≥98% assay — in two forms, because the salt you choose decides which formats you can actually make.

Also known as PQQ · pyrroloquinoline quinone disodium salt · methoxatin disodium salt · 4,5-dihydro-4,5-dioxo-1H-pyrrolo[2,3-f]quinoline-2,7,9-tricarboxylic acid disodium salt

CAS

122628-50-6

Assay

98% HPLC

Code

EA004

MOQ

from 1 g

374.17 g/molMolecular weight

C₁₄H₄N₂Na₂O₈Formula

98% HPLCPurity

Identity data as printed on the batch certificate of analysis.

On this page Identity Manufacture Applications Specification Reading the COA Documents FAQ

What PQQ is.

Pyrroloquinoline quinone is a tricyclic quinone that bacteria use as a redox cofactor. Commercially it is not synthesised from scratch: it is produced by fermentation, most commonly with Methylovorus glucosotrophus or Hyphomicrobium denitrificans, then isolated from the broth and crystallised.

The commercial question is rarely “is it PQQ” — it is which PQQ. Two things separate one lot from another, and neither shows up on the label.

First, the salt form. PQQ is sold as the disodium salt and as the free acid. The disodium salt is water-soluble, deep red-brown, and is what capsules, tablets and beverage powders are built on. The free acid is oil-soluble, which is what suspension softgels and oil-based cosmetics need. They are not interchangeable, and a quotation that just says “PQQ” has not answered the question yet.

Second, what the percentage refers to. “98% PQQ” can mean 98% PQQ disodium salt by HPLC, or 98% PQQ content expressed on the anhydrous free-acid basis. Between those two readings sits a factor of about 0.88 — a gap big enough to change your formula and your label. Our certificate states the basis it is calculated on, rather than leaving it to be inferred.

Disodium salt, ≥98% by HPLC, with chromatogram and impurity profile per batch
Assay basis stated on the COA — salt or free-acid equivalent, never averaged into one number
Water content by Karl Fischer: the figure that matters most for a hygroscopic quinone
From 1 g evaluation samples through to multi-kilogram lots

Key facts

CAS number: 122628-50-6 (disodium salt) · 72909-34-3 (free acid)
Catalogue code: EA004
Assay: ≥ 98.0% by HPLC, calculated as the disodium salt
Grade: Food / supplement
Appearance: Red-brown to deep red-brown crystalline powder
MOQ: From 1 g for evaluation; commercial quantities quoted per order
Lead time: Confirmed in writing with the quotation, against quantity and destination
Packaging: 1–100 g amber vial · 500 g foil bag · 1 kg foil bag in fibre drum · 25 kg drum

Request a quotation

COA, analytical data and SDS supplied with every batch.

The record.

The identifiers your specification sheet, customs paperwork and product label all have to agree on. Where a number depends on the salt form, both are given.

Identity

Chemical name: Pyrroloquinoline quinone disodium salt
Common name: PQQ; methoxatin disodium salt
CAS number: 122628-50-6 (disodium salt) · 72909-34-3 (free acid)
Molecular formula: C₁₄H₄N₂Na₂O₈
Molecular weight: 374.17 g/mol (disodium salt) · 330.21 g/mol (free acid)
Appearance: Red-brown to deep red-brown crystalline powder
Solubility: Disodium salt: soluble in water. Free acid: the oil-soluble form
Grade: Food / supplement
HS code: 2933.99 — indicative, confirmed per shipment
Storage: Sealed, 2–8 °C, protected from light and moisture

Molecular weight and formula as published in the FDA GRAS Notice Inventory (GRN 000641) and in supplier reference data. HS codes are indicative only; final classification is confirmed per shipment with your customs broker.

How it is made.

Four stages separate the fermentation broth from the lot you receive. Each one leaves a test result on the batch record.

Fermentation

A methylotrophic strain is grown in a two-stage fermentation, and PQQ accumulates in the broth. This is the step that decides whether the material is fermentation-derived at all — a point some suppliers leave unstated, and one your non-GMO or origin declaration may depend on.
Isolation

Filtration, then resin adsorption and elution. This step removes the bulk of the biomass and the coloured co-metabolites that would otherwise sit in the impurity profile.
Crystallisation and drying

pH adjustment and a two-stage crystallisation give the disodium salt; the product is then dried under vacuum and milled. This is where the water content is set, and PQQ holds more of it than most actives.
Release testing

Assay, identity, water, residual solvent, elemental impurities and microbiological limits are tested against the written specification before the lot is released.

Where it is used.

PQQ is a formulation ingredient, not a finished product. These are the three formats we are asked about most — and the form of PQQ each one needs.

Capsules & tablets

The disodium salt, usually in the low-milligram range per unit. Deep colour and low bulk density mean small-dose blends need a carrier; send the target fill weight and we will quote a milled grade if flow matters more than particle size.

Powder sticks & functional beverages

The disodium salt, chosen for solubility. Two constraints are worth testing early: the red-brown colour carries into the finished drink, and PQQ is light- and oxygen-sensitive in solution. Check regulatory ceilings for your market before fixing the dose.

Softgels & oil-based formats

The free acid, not the disodium salt. It disperses in the oil phase; the salt does not. If your formula is a suspension softgel or an anhydrous cosmetic base, specify the acid form at the enquiry stage.

Release criteria.

The written limits we release against, with the method used to test each one. Batch results for the lot you receive are stated on its certificate of analysis.

Typical specification, not a fixed offer. The limits below are typical for food-grade PQQ disodium salt and reflect the ranges published in FDA GRAS Notice GRN 000641 and supplier specifications. Material is released against the written specification agreed with you at order; the assay, water and residual-solvent limits in particular are set per contract, because they differ between production lines and between customers.

Parameter	Limit	Method
Appearance	Red-brown to deep red-brown crystalline powder	Visual
Assay (PQQ disodium salt)	≥ 98.0%	HPLC-UV
Assay basis	Stated on COA: as-is salt, or free-acid equivalent	Calculation
Identity	Consistent with reference	LC–MS, ¹H NMR
Water content	≤ 12.0%	Karl Fischer
Residual ethanol	≤ 0.5%	GC
Lead	≤ 1 ppm	ICP-MS
Arsenic	≤ 1.5 ppm	ICP-MS
Cadmium	≤ 0.3 ppm	ICP-MS
Mercury	≤ 0.2 ppm	ICP-MS
Total plate count	≤ 1,000 cfu/g	Plate count
Yeast & mould	≤ 100 cfu/g	Plate count
E. coli / Salmonella	Absent	Enrichment
Shelf life	24 months from date of manufacture, unopened	Stability programme

Tighter limits — a lower water ceiling, or a specified residual-solvent panel for your market — can be quoted against your own specification wording.

Reading the certificate.

Three numbers on this material are routinely misread. If a supplier cannot state them, the “98%” on the label is doing very little work.

01 · Which PQQ is being measured

A figure on the disodium salt is not a figure on the free acid. Convert with the molecular weights: 374.17 → 330.21, a factor of 0.8825. A lot at 98.0% disodium salt carries roughly 86.5% PQQ on a free-acid basis. Both numbers are correct; only one belongs on your label, and the COA should say which it is reporting.

02 · Water here is a large number, not a trace

PQQ disodium salt is hygroscopic, and food-grade specifications commonly allow water up to 12%. That is not a defect — it is the nature of the salt. But it means assay must be read on a stated basis, and it means a lot that has been opened and repacked will drift downward in assay while the chromatogram looks unchanged.

03 · The colour is the chemistry

Deep red-brown is inherent to the quinone, so a dark powder is not a bad lot. Two things are worth watching: a shift toward near-black, which usually tracks moisture and oxidation, and a batch noticeably lighter than the previous one, which can indicate a different purity or a different salt. Ask for the reference colour description, not a photograph.

What ships with it.

The paperwork travels with the goods. If your QA team needs an additional declaration, ask before the order is released — some are issued per production lot and cannot be retrofitted.

Certificate of analysis

Batch number, assay and its basis, identity, water, residual ethanol, elemental impurities and microbiological results — one page, one lot.

Analytical data

HPLC chromatogram with the integration method stated, plus the mass spectrum used for identity confirmation.

SDS & specification

Safety data sheet for handling and transport, and the written specification the batch was released against.

Declarations on request

Non-GMO, allergen, TSE/BSE, origin and fermentation-strain statements, issued against the actual production lot — tell us which your market requires.

Pack size	Presentation	Typical use
1–100 g	Amber glass vial, sealed	Evaluation and lab scale
500 g	Nitrogen-flushed foil bag	Pilot batches
1 kg	Foil bag in fibre drum	Commercial
25 kg	Fibre drum, food-grade liner	Bulk — quoted per order

Pack sizes are confirmed against stock at the time of order. Nitrogen flushing and desiccant can be specified for hygroscopic lots.

Before you order.

The questions buyers actually ask about PQQ. Anything not covered here, ask directly — you will get an answer from someone technical, not a template.

Disodium salt or free acid — which do I need?

It follows from your format, not from the assay. Water-based systems — capsules with aqueous fill, tablets, powder sticks, RTD beverages — need the disodium salt. Anhydrous oil systems, including suspension softgels and oil-phase cosmetics, need the free acid, because the salt will not disperse in oil. If you are developing both, they are two specifications, not one order with two pack sizes.

Is your PQQ fermentation-derived or chemically synthesised?

Fermentation-derived. PQQ is produced by a methylotrophic strain and isolated from the broth; the strain and the route are stated on the specification sheet. If your market requires a non-GMO or a specific-origin statement, ask for it before the first order — these are issued against the production lot and cannot be added afterwards.

What does “98%” refer to — the salt or the free acid?

On our COA, the basis is stated explicitly, and we will send the specification before you order so your QA team can compare it line by line. This matters more than the number itself: 98.0% disodium salt is about 86.5% PQQ on a free-acid basis. If a supplier quotes a percentage with no basis, the figure cannot be compared with anyone else’s.

What is the regulatory status in my market?

It differs, and it is the importer’s responsibility. PQQ disodium salt has a GRAS notice on file in the United States for use in specified beverage categories, and in China it was approved as a new food raw material, with conditions, in 2023. The European Union treats it differently again. We supply the ingredient and the documentation — we do not advise on market access, and we will not describe the material as approved anywhere that it is not.

Why is the powder red-brown?

That is the molecule. PQQ is a quinone, and the conjugated ring system absorbs in the visible range. A pale PQQ would be the thing to question. What matters is consistency batch to batch, so ask for the reference colour description on the specification rather than judging from a photograph.

Can you supply a grade for beverages?

The disodium salt is the beverage-compatible form, and we can quote a milled grade with a tighter particle-size distribution if your blending line needs it. Two formulation constraints are worth testing before you scale: the colour carries through into the finished drink, and stability in aqueous solution is limited by light and oxygen. Treat shelf life as a formulation project with your own data, not as a property of the raw material.

What is the minimum order and lead time?

Evaluation samples start at 1 g. Commercial quantities are quoted with a lead time confirmed in writing once the specification, quantity and destination are agreed. Stock lots ship faster — mention your deadline when you enquire.

How is it shipped and how should it be stored?

Ambient or cold-chain depending on destination and transit time, with desiccant in every pack. Store sealed at 2–8 °C, protected from light and moisture. Let the container reach room temperature before opening — condensation onto a hygroscopic powder is the most common way a good lot is lost.

Often quoted together.

EA001

NMN

β-Nicotinamide mononucleotide

EP003

Glutathione

Reduced L-glutathione

EA012

L-Ergothioneine

Fermentation-derived thione

EA013

Spermidine

Spermidine trihydrochloride

Ask for PQQ, by the gram.

Send the quantity, the form you need — disodium salt or free acid — and the destination. You will get a written quotation with lead time, packaging options and the documentation set for this material.