A sodium lignosulfonate Certificate of Analysis (COA) is the batch-specific quality release record supplied with a shipment. It reports the measured results for one manufactured lot and should be read together with the agreed product specification and purchase contract. Sodium lignosulfonate is sold in many powder and liquid grades, so a COA is meaningful only when its product code and specification match the grade that was ordered.
What a Shipment COA Should Identify
- Product name, grade and internal product code, CAS reference and physical form.
- Batch or lot number, production date and expiry or retest date.
- Applicable specification limits, measured results, units and test methods.
- Quality-control conclusion, issue date and authorized signature or stamp.
- Shipment references where the contract requires them.
How to Check a COA Before Accepting a Shipment
- Match the product name, grade code, CAS reference and physical form to the contract.
- Match the batch number and net weight to the packing list and container labels.
- Confirm the production and expiry dates.
- Compare every measured result with its stated specification, including units, basis and method.
- Confirm the QC conclusion and the authorized signature or stamp.
Powder and Liquid COAs Differ
Powder-grade certificates commonly report dry matter, moisture, pH, water-insoluble matter, sulfate, reducing sugar and lignosulfonate content. Liquid-grade certificates focus on solid content, density, pH, insoluble matter and other agreed composition controls. Do not compare a liquid result directly with a powder specification. For liquid grades, see the liquid sodium lignosulfonate COA guide.
Example: Grade One Powder Reference Specification
The table shows the typical values in the current technical data sheet for Sodium Lignosulfonate Grade One (GAC-NaLS-1, Revision 2.0). It illustrates the fields a powder COA reports; actual results change by batch and appear only on the official shipment COA.
| Parameter | Reference value (GAC-NaLS-1 TDS) |
|---|---|
| Appearance | Yellow-brown powder |
| pH (10% solution) | 7.0–9.5 |
| Dry matter | 95% min |
| Water-insoluble matter | 1.5% max |
| Water-reducing capacity | 8% min |
| Sulphate (SO42−) | 2–5% |
| Calcium and magnesium | 0.5% max |
| Lignosulphonate content | 55% min |
| Reducing sugar | 7% max |
| Moisture | 7% max |
Other grades, such as Grade Two or construction, dispersant and feed grades, have different specifications. Do not apply these values to them.
COA, TDS and SDS Are Different Documents
| Document | Purpose |
|---|---|
| COA | Reports quality-control results for a specific batch. |
| TDS | Describes the product grade, typical properties, applications and handling guidance. |
| SDS | Provides safety, hazard, storage, first-aid and transport information in the applicable format. |
Packaging and Storage (GAC-NaLS-1)
Packed in 20 kg or 25 kg woven bags with a polyethylene liner, or 500 kg or 600 kg jumbo bags. Store in a cool, dry, well-ventilated area and reseal opened bags. The TDS states a shelf life of 24 months from production in original unopened packaging.
How to Request the Correct Documents
Before ordering, provide the application, required grade, target specification, any prescribed test method, quantity, packing and destination. Pre-shipment or third-party inspection can be discussed where commercially required. The final document set is issued against the confirmed product and shipment. See the sodium lignosulfonate product page, and email info@greenagrochem.com to request the current TDS, SDS, specification or a signed batch COA.
