Jun 08

Who is the purest of them all? The need for high quality certified reference standards

Thousands of decisions based on chemical measurements are made globally each day. This could be a clinician making a medical diagnosis, regulators identifying the presence of counterfeit drugs and removing them from sale, or a water treatment company testing their processes to ensure the water you drink is safe.

To underpin these measurements and ensure we all have confidence in them, they are calibrated through a series of reference materials – from those run on a day-to-day basis up to the highest (primary) level. The cornerstone of this reference material system is the provision of high purity reference standards as the primary calibrators, such as those produced by LGC in our role as the National Measurement Laboratory and Designated Institute for chemical and bio-measurement.

Industry increasingly requires a greater number, range and complexity of high purity reference standards to support the challenging measurements of real-world samples. This means primary calibrators must have values assigned more quickly and at significantly lower cost than traditional methods currently allow.

To address this need, scientists at LGC have been implementing the technique of quantitative nuclear magnetic resonance (qNMR). Purity determination by qNMR is much faster than traditional methods and allows for direct assay of the compound of interest rather than inferring the purity through quantitation of the myriad of minor impurities potentially present.

The use of qNMR for purity determination has been rigorously assessed and validated at LGC and its use as a primary method (with direct traceability to the international system of units, SI) has been standardised through comparison studies between National Measurement Institutes.

Earlier this year (2017) LGC became one of the few laboratories worldwide to gain ISO17025 accreditation for purity of organic materials by qNMR. The extent of the ISO17025 scope includes the determination of the purity of organic analytes of high purity (>90%) with a molecular weight of <1000 g/mol.

This accreditation provides demonstrable evidence of LGC’s expertise and supports our new qNMR facility in providing reference material characterisation and quantitative measurement research for customers across the AgBio, biopharmaceutical, chemicals, consumer products and forensic industries.


If you would like to find out how we could use our NMR expertise to address your measurement challenges, please contact LGC’s Measurement Services.

LGC is accredited to ISO Guide 34 for the production of reference materials.


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