Start with the decision the report must support: identity, chromatographic purity, quantitative content, water, process residues or another defined attribute. Share the product identity, batch or sample reference, sample form and expected quantity with the laboratory.
Before sending material, confirm the method, sample amount, handling instructions, fees, timing, report format and the laboratory’s relevant scope. Record how the sample was identified, sealed and transferred. The independent laboratory should issue its own report for the submitted sample.
See the ISO/IEC 17025 overview for information about laboratory competence and impartiality.