Characterization of the purity of phytotherapics from secondary vegetal metabolism with small-scale coulometry applied to perillic acid
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The use of pure materials in chemical analysis is currently in high demand due to the need to provide reliable measurement results. Phytotherapics are natural products that contain substances of secondary vegetal metabolism. Perillic acid, a monoterpenic acid with anti-inflammatory and anticancer properties, was the phytotherapic chosen to be analyzed in this work for purity by coulometry. Due to the low availability of perillic acid on the market and its high cost, the miniaturization of the coulometric technique was fundamental for characterizing such a substance. The volume of the supporting electrolyte and the mass of the analyte were the main parameters scaled. The coulometric measurement results were obtained by small-scale coulometry by using 3.0 mg of perillic acid (scale reduction of ×100). A mean purity of (94.2 ± 0.8)% (k = 2.13, for an approximately 95% confidence level) was obtained from five replicates. These studies aim in the future to develop the production of certified reference materials from natural products.
KeywordsCharacterization Small-scale coulometry Phytotherapic Perillic acid
The author L. C. Norte acknowledges the Inmetro and the Fiocruz, where the studies are being developed.
- 3.De Briève P, Dybkaer R, Fajgelj A, Hibbert DB (2011) Pure Appl Chem 83 10:1873-1935Google Scholar
- 5.ISO Guide 35 (2017) Reference materials—guidance for characterization and assessment of homogeneity and stabilityGoogle Scholar
- 8.Szebellédy L, Somogyi D (1938) Die coulometrische Analyse als Präzisionsmethode. Fresenius Z Anal Chem 112:313–323Google Scholar
- 9.Bishop E (1975) Coulometric analysis. In: Wilson CL, Wilson DW (eds) Comprehensive analytical chemistry, vol IID. Elsevier, AmsterdamGoogle Scholar
- 11.Curran DJ (1996) Controlled-current coulometry. In: Kissinger PT, Heineman WR (eds) Laboratory techniques in electroanalytical chemistry, 2nd edn. Dekker, New York, pp 739–768Google Scholar
- 13.RDC 26/2014 (2014) Diário Oficial da União (DOU) 14.05.14 BrasilGoogle Scholar
- 16.CODATA. https://physics.nist.gov/cgi-bin/cuu/Value?f|search_for=abbr_in! Accessed in 15.07.17
- 17.JCGM 100 (2008) Evaluation of measurement data—guide to the expression of uncertainty in measurement. http://www.bipm.org/utils/common/documents/jcgm/JCGM_100_2008_E.pdf. Accessed in 15.07.17
- 18.Ellison, SLR, Williams A (Eds) (2012) Eurachem/CITAC guide quantifying uncertainty in analytical measurement, Third edition, ISBN 978–0–948926-30-3 Available from https://www.eurachem.org/index.php/publications/guides/quam
- 20.Thompson M, Ellison SLR, Wood R (2002) Harmonized guidelines for single-laboratory validation of methods of analysis. Pure Appl Chem 74(5):835–855Google Scholar