How to Account for MDEA Assay in a Dilution Calculation

A batch plan calls for 1,000 kg of 40 wt% N-methyldiethanolamine (MDEA, CAS 105-59-9) solution. The incoming material is confirmed as 99.0 wt% MDEA. Including that assay in the mass balance gives the amount of supplied product required for the target concentration.

Start with the contained MDEA requirement

Mass fraction is the mass of a component divided by the total mass of the mixture. A target of 40 wt% MDEA therefore means a mass fraction of 0.40. mass fraction (M03722)

Required MDEA mass = final batch mass × target MDEA mass fraction

For this hypothetical batch:

1,000 × 0.40 = 400 kg of MDEA

Calculate the incoming product quantity

Divide the contained MDEA requirement by the incoming product’s confirmed mass fraction.

Incoming product mass = required MDEA mass ÷ incoming MDEA mass fraction

400 ÷ 0.99 = 404.04 kg of incoming product

If the batch contains only this supplied product and added water, with no material losses, the calculated water addition is:

1,000 − 404.04 = 595.96 kg

The incoming product contributes both MDEA and its remaining constituents to the final batch.

Confirm that the assay is suitable for the calculation

Use an assay expressed as MDEA weight percent in the product as delivered. If the certificate reports GC area percent or a dry-basis value, ask the supplier or laboratory to confirm the mass-based concentration needed for the calculation.

For a formulated solvent, account separately for any specified promoters or other components. Have the process team approve the batch calculation and preparation requirements before production.

Keep the calculation with the batch records

Record the raw-material lot, assay basis, target concentration and actual weighed quantities. Apply the agreed final-product testing and release criteria so the production record connects the calculation with the finished batch.

Send China Amines Co., Limited your required grade, mass-based assay requirements, order quantity, preferred packaging and destination port. Include any batch documentation needed for your formulation calculations.

Inquiries
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Technical references

• IUPAC Gold Book — Mass Fraction
• Amines & Plasticizers Limited — Methyl Diethanolamine Technical Data Sheet