title: Using high-performance ¹H NMR (HP-qNMR®) for the certification of organic reference materials under accreditation guidelines--describing the overall process with focus on homogeneity and stability assessment.
abstract: Quantitative NMR spectroscopy (qNMR) is gaining interest across both analytical and industrial research applications and has become an essential tool for the content assignment and quantitative determination of impurities. The key benefits of using qNMR as measurement method for the purity determination of organic molecules are discussed, with emphasis on the ability to establish traceability to "The International System of Units" (SI). The work describes a routine certification procedure from the point of view of a commercial producer of certified reference materials (CRM) under ISO/IEC 17025 and ISO Guide 34 accreditation, that resulted in a set of essential references for (1)H qNMR measurements, and the relevant application data for these substances are given. The overall process includes specific selection criteria, pre-tests, experimental conditions, homogeneity and stability studies. The advantages of an accelerated stability study over the classical stability-test design are shown with respect to shelf-life determination and shipping conditions.
authors.affiliation: Sigma-Aldrich Switzerland, Industriestrasse 25, CH-9471 Buchs, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.affiliation: Sigma-Aldrich Switzerland, Industriestrasse 25, CH-9471 Buchs, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Hellriegel
authors.affiliation: Sigma-Aldrich Switzerland, Industriestrasse 25, CH-9471 Buchs, Switzerland. Electronic address: alexander.rueck@sial.com.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rueck
authors.affiliation: Sigma-Aldrich Switzerland, Industriestrasse 25, CH-9471 Buchs, Switzerland.
authors.forename: Juerg
authors.initials: J
authors.lastname: Wuethrich
authors.affiliation: Sigma-Aldrich Switzerland, Industriestrasse 25, CH-9471 Buchs, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Jenks
mesh_terms: D000068:Accreditation; D002568:Certification / Q000379:methods*; D004355:Drug Stability; D004356:Drug Storage; D017408:Guidelines as Topic; D009930:Organic Chemicals / Q000032:analysis* / Q000592:standards; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D012015:Reference Standards
chemical_list: D009930:Organic Chemicals
keywords: Accreditation; CRM; Stability testing; Traceability; qNMR