Skip to main content
SpringerLink
Log in

Microdetermination of organic isothiocyanates alone and in the presence of isocyanates or thioureas

  • Published:
Microchimica Acta Aims and scope Submit manuscript

Summary

A method for the determination of organic isothiocyanates is described. The isothiocyanates on reacting with excess ofn-butylamine in dimethylformamide form N,N′-disubstituted thioureas which are determined by oxidation with iodine trichloride. Each mole of thiourea consumes 8 oxidizing equivalents. Two procedures for determining mixtures of isothiocyanate and isocyanate or thiourea are also presented. In the first procedure, a total of isothiocyanate and isocyanate is determined by reacting the mixture with excessn-butylamine and back titrating the residual amine acidimetrically. The isothiocyanate content is determined on a second aliquot by iodine trichloride oxidation of the thioureas formed from isothiocyanate by its reaction with amine. In the second procedure, the isothiocyanate is determined by reaction with excess amine and following an acidimetric titration. Then, the thiourea originally present plus that formed from isothiocyanate, upon reaction with the second aliquot withn-butylamine, are determined by iodine trichloride oxidation. Acidic or basic substances, carbonyl compounds and anhydrides do not interfer.

Zusammenfassung

Isothiocyanate bilden bei Reaktion mit einem Überschuß vonn-Butylamin in Dimethylformamid N,N′-disubstituierte Thioharnstoffe, die sich durch Oxydation mit Jodtrichlorid bestimmen lassen. Pro Mol Thioharnstoff werden 8 Oxydationsäquivalente verbraucht. Außerdem wurden zwei Verfahren zur Bestimmung von Gemischen aus Isothiocyanat und Isocyanat oder Thioharnstoff angegeben. Bei dem einen Verfahren wird die Summe von Isothiocyanat und Isocyanat durch Umsetzung mit einem Überschuß vonn-Butylamin und Rücktitration mit Säure bestimmt. Das Isothiocyanat wird in einem zweiten Probeanteil durch Oxydation des aus Isothiocyanat mit Amin gebildeten Thioharnstoffs bestimmt. Bei dem zweiten Verfahren wird das Isothiocyanat durch Umsetzung mit überschüssigem Amin und nachfolgender acidimetrischer Titration bestimmt. Dann wird der ursprünglich vorhandene Thioharnstoff und der aus Isothiocyanat bei der Umsetzung mit einem zweiten Aliquotn-Butylamin entstandene Thioharnstoff durch Oxydation mit Jodtrichlorid bestimmt. Saure oder basische Substanzen, Carbonylverbindungen und Anhydride stören nicht.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Literatur

  1. N. D. Cheronis and T. S. Ma, Organic Functional Group Analysis, New York: Wiley. 1964. p. 297.

    Google Scholar 

  2. S. Siggia and J. G. Hanna, Analyt. Chemistry20, 1084 (1948).

    Google Scholar 

  3. B. S. Karten and T. S. Ma, Microchem. J.3, 507 (1959).

    Google Scholar 

  4. J. A. Vinson, Analyt. Chemistry41, 1661 (1969).

    Google Scholar 

  5. P. C. Gupta, Z. analyt. Chem.196, 412 (1963).

    Google Scholar 

  6. P. Raizman and Q. E. Thompson in J. H. Karchmer (ed.), The Analytical Chemistry of Sulfur and Its Compounds, Part II, New York: Wiley. 1972. p. 672.

    Google Scholar 

  7. P. C. Gupta, Analyst88, 896 (1963).

    Google Scholar 

  8. R. D. Tiwari and U. C. Pande, Analyst94, 813 (1969).

    Google Scholar 

  9. L. Suchomelova and J. Zyka, J. Electroanalyt. Chemistry5, 57 (1963).

    Google Scholar 

  10. B. Singh and B. C. Verma, J. Scient. Ind. Research24, 536 (1965).

    Google Scholar 

  11. K. K. Verma, M. P. Sahasrabuddhey and S. Bose, Talanta24, 515 (1977).

    Google Scholar 

  12. B. C. Verma and S. Kumar, Analyst98, 900 (1973).

    Google Scholar 

  13. B. C. Verma and S. Kumar, Talanta22, 921 (1975).

    Google Scholar 

  14. B. C. Verma and S. Kumar, Talanta20, 916 (1973).

    Google Scholar 

  15. K. K. Verma and S. Bose, J. Indian Chem. Soc.50, 499 (1973).

    Google Scholar 

  16. P. D. Sharma and Y. K. Gupta, Talanta21, 168 (1974).

    Google Scholar 

  17. Y. A. Fialkov and F. E. Kagan, Ukrain. Khim. Zhur.18, 55 (1952).

    Google Scholar 

  18. F. E. Kagan, Ukrain. Khim. Zhur.22, 94 (1956).

    Google Scholar 

  19. A. I. Vogel, A Text-Book of Quantitative Inorganic Analysis, London: Longman. 1968. p. 349.

    Google Scholar 

  20. N. L. Drake, Organic Syntheses21, 81, 83 (1941).

    Google Scholar 

  21. A. I. Vogel, A Text-Book of Practical Organic Chemistry, London: Longman. 1968. p. 644.

    Google Scholar 

  22. F. B. Dains, R. Q. Brewster, and C. P. Olander, Organic Syntheses3, 447 (1955).

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Chemistry, Government Science College, 482001, Jabalpur, India

    Krishna K. Verma

Authors
  1. Krishna K. Verma
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Verma, K.K. Microdetermination of organic isothiocyanates alone and in the presence of isocyanates or thioureas. Mikrochim Acta 70, 385–394 (1978). https://doi.org/10.1007/BF01197090

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01197090

Keywords

Search

Navigation