Mass fraction assignment of folic acid in a high purity material

Abstract

The comparison required the assignment of the mass fraction of folic acid present as the main component in the comparison sample. Performance in the comparison is representative of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molecular weight range 300–500] and high polarity (pKOW < −2). Methods used by the eighteen participating NMIs or DIs were based on a mass balance (summation of impurities) or qNMR approach, or the combination of data obtained using both methods. The qNMR results tended to give slightly lower values for the content of folic acid, albeit with larger associated uncertainties, compared with the results obtained by mass balance procedures. Possible reasons for this divergence are discussed in the report, without reaching a definitive conclusion as to their origin. The comparison demonstrates that for a structurally complex polar organic compound containing a high water content and presenting a number of additional analytical challenges, the assignment of the mass fraction content property value of the main component can reasonably be achieved with an associated relative standard uncertainty in the assigned value of 0.5% Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Development of nuclear magnetic resonance as a tool of quantitative analysis for organic materials

“…The analysts also must consider sample stability issues. The life time of a sample may be short compared to the intended experiment time [38]. It is important to check the stability of the sample during the planned experimental time.…”

“…One participant submitted the result solely on a qNMR result using same peak, the result was significantly biased by the decomposition for the quantification. [38]. Because many NMIs reported small uncertainties compared to the dispersion of the results among participating NMIs, evaluation of uncertainty associated with the result needs improvement.…”

News from the BIPM laboratories—2018

“…Within the BIPM's small organic primary calibrator programme, the final report of the CCQM-K55.d comparison on folic acid purity was published [31]. The final report for the CCQM-K78.a comparison on multi-component amino acid calibration solutions was completed and circulated to the CCQM for approval in November 2018.…”

Analytical Methods Based on the Mass Balance Approach for Purity Evaluation of Tetracycline Hydrochloride

“…Because, as mentioned earlier, salt aids in compound solubility, accurate detection of the free base in the salt compound is critical for drug residue analysis. Hence, the Bureau International des Poids et Mesures (BIPM) conducted the Capacity Building and Knowledge Transfer program for tetracycline purity evaluation, and our laboratory participated as a national metrology institute with established capabilities in pure organic material characterization [22]. This study demonstrates a detailed characterization method for assigning the mass fractions of salt and free forms in high-purity TCH materials.…”