Application of direct and indirect methods for determining the mass fraction of the main component in flotation potassium chloride

The article is devoted to the comparison of two approaches to determining the purity of metal salts on the example of a complex in composition object - flotation potassium chloride. The results of determining the mass fraction of the main component (potassium chloride) in flotation potassium chloride obtained by direct (using the coulometric titration method with correction for anions titrated with the determined chloride ion and an excess of cations) and indirect (according to the scheme 100% minus the amount of impurities with regard to their species) methods. It is shown that direct and indirect methods give well consistent results: (96.08 ± 0.17) % and (96.11 ± 0.12) %, respectively. Also, the measurement results obtained using the standard installations considering the uncertainty are well consistent with the certified value of the mass fraction of potassium chloride (96.11 ± 0.11) %, obtained based on an interlaboratory experiment in laboratories that perform measurements in accordance with GOST 20851.3. The feature of the direct and indirect methods implemented in this work is the construction of a model of the chemical composition of the analysed object based on a priori and experimental data using two basic principles when summing up the content of impurities: the conditions of material balance and the principle of electroneutrality.

1. Deviatykh G. G., Kovalev I. D., Malyshev K. K. Osipova L. I., Stepanov V. M., lankov S. V. Analysis of data on impurity composition of samples of simple solids. Vysokochistye veshchestva. 1992;(5-6):7-11. (In Russ.).

2. Deviatykh G. G., Stepanov V. M., Iankov S. V. Probabilistic description of purification processes and impurity composition of high-purity substances. Vysokochistye veshchestva. 1988;(2):5-19. (In Russ.).

3. Deviatykh G. G. et al. Assessment of the reliability and completeness of data on the impurity composition of high-purity volatile compounds. Neorganicheskie materialy. 2001;37:371-375. (In Russ.).

4. Kovalev I. D. et al. Impurity composition of the samples of the exhibition-collection of high-purity substances of simple solids, permanent gases, volatile chlorides, hydrides and organometallic compounds. Neorganicheskie materialy. 1994;(4):5-10. (In Russ.).

5. Deviatykh G. G. et al. Standard sample of the composition of high-purity copper. Vysokochistye veshchestva. 1987;(5):153-161. (In Russ.).

6. Deviatykh G. G. et al. Distribution function of impurity content for samples of simple high-purity substances. Vysokochistye veshchestva. 1992;(5-6):48-53. (In Russ.).

7. Deviatykh G. G., Karpov Iu. A., Osipova L. I. Exhibition-collection of substances of special purity. Moscow: Nauka; 2003. 236 p. (In Russ.).

8. Malyshev K. K., Stepanov V. M. Statistical estimation of the total concentration of impurities from incomplete analysis data on the example of Te, Mn, Al. Vysokochistye veshchestva. 1990;(2):229-235. (In Russ.).

9. Certification of the mass fraction of copper in Primary Reference Material BAM Y001: Kipphardt H. (ed.). Certification Report.2004. 46 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y001repe.pdf?__blob=publicationFile (accessed 08.11.2021).

10. Certification of the mass fraction of iron in Primary Reference Material BAM Y002: Kipphardt H. (ed.). Certification Report. 2004. 36 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y002repe.pdf?__blob=publicationFile (accessed 08.11.2021).

11. Certification of the mass fraction of silicon in Primary Reference Material BAM: Kipphardt H. (ed.). Certification Report. 2004. 25 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y003repe.pdf?__blob=publicationFile (accessed 08.11.2021).

12. Certification of the mass fraction of lead in Primary Reference Material BAM Y004: Kipphardt H. (ed.). Certification Report. 2004. 25 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y004repe.pdf?__blob=publicationFile (accessed 08.11.2021).

13. Certification of the mass fraction of tin in Primary Reference Material BAM Y005: Kipphardt H. (ed.). Certification Report. 2004. 26 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y005repe.pdf?__blob=publicationFile (accessed 08.11.2021).

14. Certification of the mass fraction of tungsten in Primary Reference Material BAM: Kipphardt H. (ed.). Certification Report. 2004. 24 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y006repe.pdf?__blob=publicationFile (accessed 08.11.2021).

15. Certification of the mass fraction of bismuth in Primary Reference Material: Kipphardt H. (ed.). Certification Report. 2004. 25 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y007repe.pdf?__blob=publicationFile (accessed 08.11.2021)

16. Certification of the mass fraction of gallium in Primary Reference Material BAM Y008: Kipphardt H. (ed.). Report. 2004. 26 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y008repe.pdf?__blob=publicationFile (accessed 08.11.2021).

17. Certification of the mass fraction of sodium chloride in Primary Reference Material BAM Y009: Kipphardt H. (ed.). Certification Report. 2004. 26 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y009repe.pdf?__blob=publicationFile (accessed 08.11.2021).

18. Certification of the mass fraction of potassium chloride in Primary Reference Material BAM Y010: Kipphardt H. (ed.). Certification Report. 2004. 26 p. Available at: https://rrr.bam.de/RRR/Content/EN/Downloads/RM-Certificates/RM-cert-primary-pure-substances/bam_y010repe.pdf?__blob=publicationFile (accessed 08.11.2021).

19. Kipphardt H., Matschat R., Vogl J. et al. Purity determination as needed for the realisation of primary standards for elemental determination: status of international comparability. Accreditation and Quality Assurance. 2010;15:29-37. https://doi.org/10.1007/s00769-009-0557-0

20. SRM 3144 Rhodium (Rh) Standard Solution: Certificate of Analysis: NIST. Available at: https://www-s.nist.gov/srmors/certificates/3144.pdf (accessed 08.11.2021).

21. Salit M. L., Turk G. C. Traceability of Single-Element Calibration Solutions. Analytical chemistry. 2005;77(7):136 A-141 A. https://doi.org/10.1021/ac053354n

22. Salit M. L., Turk G. C., Lindstrom A. P., Butler T. A., Beck C. M., Norman B. Single-Element Solution Comparisons with a High-Performance Inductively Coupled Plasma Optical Emission Spectrometric Method. Analytical chemistry. 2001 ;73(20):4821-4829. https://doi.org/10.1021/ac0155097

23. Rukhin A. L. Compatibility Verification of Certified Reference Materials and User Measurements. Metrologia. 2014;51(1):11-17. https://doi.org/10.1088/0026-1394/51/1711

24. Rukhin A. L. Maximum Likelihood and Restricted Likelihood Solutions in Multiple-Method Studies. Journal of research of the National Institute of Standards and Technology. 2011;116(1):539-556. https://doi.org/10.6028/jres.116.004

25. Levenson M. S., Banks D. L., Eberhardt K. R., Gill, Guthrie W. F., Liu H. K. et al. An Approach to Combining Results L. M. From Multiple Methods Motivated by the ISO GUM. Journal of research of the National Institute of Standards and Technology. 2000;105(4):571 -579. https://doi.org/10.6028/jres.105.047

26. Parris R. M., Beck C. M., Fassett J. D., Greenberg, R. R., Guenther F. R., Kramer G. W. et al. Definitions of Terms and Modes Used at NIST for Value-Assignment of Reference Materials for Chemical Measurements: NIST. 2000. Available at: https://www.semanticscholar.org/paper/Definitions-of-Terms-and-Modes-Used-at-NIST-for-of-May-Parris/5f8058db9dbedc27e8d957866c47b55604c5d1b9#paper-header (accessed 08.11.2021).

27. Medvedevskikh S. V., Sobina E. P., Migal P. V., Goryaeva L. I., Gorbunova E. M., Tabatchikova T. N. et al. On the use of pure inorganic substances in metrology of analytical measurements. Measurement Standards. Reference Materials. 2014;(3):58-67. (In Russ.).

28. Vogl J., Kipphardt H., Richter S., Bremser W. et al. Establishing comparability and compatibility in the purity assessment of high purity zinc as demonstrated by the CCQM-P149 intercomparison. Metrologia. 2018;55:211-221. https://doi.org/10.1088/1681-7575/aaa677

29. RMG 29-2013 State system for ensuring the uniformity of measurements. Metrology. Basic terms and definitions. Standartinform Publ.; Moscow: 2014. 56 p. (In Russ.).

30. GOST 4568-95 Potassium chloride. Specifications. PPC Izdatel’stvo Standartov; Moscow: 1996. 16 p. (In Russ.).

31. GOST 20851.3-93 Mineral fertilizers. Methods for determination of pottassium content. PPC Izdatel’stvo Standartov; Moscow: 1995. 44 p. (In Russ.).

32. Skutina A. V., Terentiev G. I. State primary standard of units of mass (mole) fraction and mass (molar) concentration of a component in liquid and solid substances and synthetic materials on the basis of coulometric titration. Measurement Techniques. 2011;54(9): 964-970. https://doi.org/10.1007/s11018-011-9835-4

33. Gorbunova E. M., Goryaeva L. I., Medvedevskikh S. V., Migal P. V., Paneva V. I., Sobina E. P., Stepanov A. S. et al. National secondary standard for the units of mass fraction and mass (molar) concentration of metals in liquids and solid substances and materials. Measurement techniques. 2013;56(7):743-746. https://doi.org/10.1007/s11018-013-0275-1

34. Gorshkov V. V., Koryakov V. I., Medvedevskikh M. Yu., Medvedevskikh S. V. State primary standard of unit of mass fraction and unit of mass concentration of moisture in solid substances and solid fabricated materials. Measurement Techniques. 2010;53(4):386-390. https://doi.org/10.1007/s11018-010-9515-9

35. Liandi1 M. A., Bing W. U., Mariassy M., Pratt K. W., Hwang E. et al. CCQM-K48.2014: assay of potassium chloride. Metrologia. 2016;53:08012. https://doi.org/10.1088/0026-1394/53/1A/08012

36. Mariassy M., Hankova Z., Hwang E., Lim Y., Pratt K. W., Hioki A. et al. Final report on key comparison CCQM-K96: Determination of amount content of dichromate. Metrologia. 2013;50:08012. https://doi.org/10.1088/0026-1394/50/1A/08012

37. Molloy J. L, Winchester M. R., Butler T. A., Possolo A. M., Rienitz O., Roethke A. et al. CCQM-K143 comparison of copper calibration solutions prepared by NMIs/Dis. Metrologia. 2020;58:08006. https://doi.org/10.1088/0026-1394/58/1A/08006

38. Sobina E. P. СООМЕТ 672 / RU / 15 Pilot comparisons in the field of measuring the mass fraction of iron in pure iron. Available at: http://www.coomet.org/DB/isapi/cmt_docs/2018/10/G6AU0R.pdf (accessed 08.11.2021).

39. Yang Lu, Nadeau K., Pihillagawa I. G., Meija J., Grinberg P., Mester Z. et al. Final report of the SIM.QM-S7 supplementary comparison, trace metals in drinking water. Metrologia. 2018;55:08002. https://doi.org/10.1088/0026-1394/55/1A/08002

40. GOST R34100.3-2017 Measurement uncertainty. Part 3. Guidance on the expression of measurement uncertainty. Standardinform; Moscow: 2018. 105 p. (In Russ.).