Interlaboratory study of the method for direct determination of volatile compounds in alcoholic products using ethanol as internal standard
Keywords:
internal standard, reference method, volatile compounds, spirit products, interlaboratory studyAbstract
A collaborative interlaboratory study of the method of direct determination of volatile compounds in spirit drinks and alcoholic products was performed. The proposed method employs ethanol, the major volatile component of an alcoholic product, as an internal standard. For the experiment realization, 9 laboratories from 4 countries – Belarus, Czech Republic, Turkey, Russia – were supplied with standard solutions for gas chromatographic measurements. Five aqueous ethanol 40 % (v/v) standard solutions containing target compounds in concentrations ranging from 10 to 400 mg/L of absolute alcohol were gravimetrically prepared and delivered to the participants. The interlaboratory study was evaluated according to the ISO 5725 standards and the «EuroChem» guide. The repeatability limits (within-laboratory precision) varied between 0.4 and 7.5 % for all samples and compounds, showing a sufficiently high repeatability of the method. The reproducibility limits (between-laboratory precision) were found to vary within a satisfactory range of 0.5–10.0 %. Precision of the method was well within the range predicted by the Horwitz equation for all analytes. In the study experimental estimation of trueness was performed for the first time. Analysis of the obtained results showed that the bias of the method is insignificant at the significance level 5 %. The experimentally determined concentrations of the analytes compared well to the gravimetrical values, thus showing very satisfactory accuracy of the method. The results of the interlaboratory study confirmed that the method «ethanol as internal standard» is robust and reliable and can be used as a standard method for the determination of volatile compounds in water-ethanol samples. Moreover, this method can be validated in any one laboratory without performing additional experimental studies based on the results obtained by validation of the traditional method.
References
- Determination of the principal volatile substances of spirit drinks of viti-vinicultural origin. Method: OIV-MA-BS-14: R2009. In: Compendium of international methods of spirituous beverages of vitivinicultural origin. Paris: International Organisation of Vine and Wine; 2019.
- Community reference methods for the analysis of spirits drinks: EC 2870/2000. Brussels: The Commission of the European Communities; 2002. 47 p.
- GOST 30536-2013. Interstate Standard 30536-2013. Vodka and ethyl alcohol from food raw materials. Gas chromatographic express method for determining the content of toxic microimpurities. Moscow: Interstate Council for Standardization, Metrology and Certification; 2013. 21 p. Russian.
- GOST 31684-2012. State Standard 31684-2012. Raw ethyl alcohol from food raw materials. Gas chromatographic method for determining the content of volatile organic impurities. Moscow: Interstate Council for Standardization, Metrology and Certification; 2012. 16 p. Russian.
- GOST 33834-2016. Interstate Standard 33834-2016. Wine production and raw materials for its production. Gas chromatographic method for determining the mass concentration of volatile components. Minsk: Eurasian Council for Standardization, Metrology and Certification; 2016. 15 p. Russian.
- GOST 33408-2015. State Standard 33408-2015. Cognac, cognac distillates, brandy. Determination of aldehydes, esters and alcohols by gas chromatography. Minsk: Eurasian Council for Standardization, Metrology and Certification; 2015. 18 p. Russian.
- Charapitsa SV, Sytova SN, Korban AL, Sobolenko LN. Single-Laboratory Validation of a Gas Chromatographic Method of Direct Determination of Volatile Compounds in Spirit Drinks: Need for an Improved Interlaboratory Study. Journal of AOAC International. 2019;102(2):669–672. DOI: 10.5740/jaoacint.18-0258.
- Charapitsa S, Sytova S, Korban A, Boyarin N, Shestakovich I, Čabal R. The Establishment of Metrological Characteristics of the Method «Ethanol as Internal Standard» for the Direct Determination of Volatile Compounds in Alcoholic Products. Journal of Chemical Metrology. 2018;12(1):59–69. DOI: 10.25135/jcm.14.18.02.063.
- Charapitsa SV, Kavalenka AN, Kulevich NV, Makoed NM, Mazanik AL, Sytova SN, et al. Direct Determination of Volatile Compounds in Spirit Drinks by Gas Chromatography. Journal of Agricultural and Food Chemistry. 2013;61(12):2950–2956. DOI: 10.1021/jf3044956.
- Kelly J, Chapman S, Brereton P, Bertrand A, Guillou C, Wittkowski R. Gas Chromatographic Determination of Volatile Congeners in Spirit Drinks: Interlaboratory Study. Journal of AOAC International. 1999;82(6):1375–1388.
- ASTM D4307-99. Standard practice for preparation of liquid blends for use as analytical standards. Philadelphia: American Society for Testing and Materials; 1999.
- ISO 5725-1994. Accuracy (trueness and precision) of measurement methods and results. Parts 1–6. Minsk: The State Committee for Standardization of the Republic of Belarus; 2002. Russian.
- EUROLAB Technical Report 1/2007. Measurement uncertainty revisited: alternative approaches to uncertainty evaluation. Paris: EUROLAB; 2007.
- AOAC Appendix D: Guidelines for Collaborative Study Procedures to Validate Characteristics of a Method of Analysis. Geneva: AOAC; 2002.
- Yilmaztekin M, Cabaroglu T. Confirmatory Method for the Determination of Volatile Congenersand Methanol in Turkish Raki According to European Union Regulation (EEC) No. 2000R2870: Single-Laboratory Validation. Journal of AOAC International. 2011;94(2):611–617.
- Method «Ethanol as Internal Standard» [Internet]. 2019 [cited 2019 September 13]. Available from: http://www.inp.bsu.by/ethanol/en/index.html.
Downloads
Additional Files
Published
Issue
Section
License
The authors who are published in this journal agree to the following:
- The authors retain copyright on the work and provide the journal with the right of first publication of the work on condition of license Creative Commons Attribution-NonCommercial. 4.0 International (CC BY-NC 4.0).
- The authors retain the right to enter into certain contractual agreements relating to the non-exclusive distribution of the published version of the work (e.g. post it on the institutional repository, publication in the book), with the reference to its original publication in this journal.
- The authors have the right to post their work on the Internet (e.g. on the institutional store or personal website) prior to and during the review process, conducted by the journal, as this may lead to a productive discussion and a large number of references to this work. (See The Effect of Open Access.)














