title: Purity assessment of organic calibration standards using a combination of quantitative NMR and mass balance.
abstract: Quantitative NMR spectroscopy (qNMR) has been examined for purity assessment using a range of organic calibration standards of varying structural complexities, certified using the traditional mass balance approach. Demonstrated equivalence between the two independent purity values confirmed the accuracy of qNMR and highlighted the benefit of using both methods in tandem to minimise the potential for hidden bias, thereby conferring greater confidence in the overall purity assessment. A comprehensive approach to purity assessment is detailed, utilising, where appropriate, multiple peaks in the qNMR spectrum, chosen on the basis of scientific reason and statistical analysis. Two examples are presented in which differences between the purity assignment by qNMR and mass balance are addressed in different ways depending on the requirement of the end user, affording fit-for-purpose calibration standards in a cost-effective manner.
authors.affiliation: Chemical Reference Materials, National Measurement Institute, P.O. Box 138, North Ryde, NSW, 1670, Australia.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Davies
authors.forename: Kai
authors.initials: K
authors.lastname: Jones
authors.forename: Anna
authors.initials: A
authors.lastname: Goldys
authors.forename: Mahuiddin
authors.initials: M
authors.lastname: Alamgir
authors.forename: Benjamin K H
authors.initials: BK
authors.lastname: Chan
authors.forename: Cecile
authors.initials: C
authors.lastname: Elgindy
authors.forename: Peter S R
authors.initials: PS
authors.lastname: Mitchell
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Tarrant
authors.forename: Maya R
authors.initials: MR
authors.lastname: Krishnaswami
authors.forename: Yawen
authors.initials: Y
authors.lastname: Luo
authors.forename: Michael
authors.initials: M
authors.lastname: Moawad
authors.forename: Douglas
authors.initials: D
authors.lastname: Lawes
authors.forename: James M
authors.initials: JM
authors.lastname: Hook
mesh_terms: D002138:Calibration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards*; D008962:Models, Theoretical; D012015:Reference Standards