Chloral hydrate as an accelerant for the Weissler reaction

• Published in: Journal of the Chinese Chemical Society (Taipei) Vol. 68; no. 7; pp. 1243 - 1249
• Main Authors: Pan, Hsin‐Yu, Chen, Nelson G.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley‐VCH Verlag GmbH & Co. KGaA 01.07.2021; Wiley Subscription Services, Inc
• Subjects: Absorptivity; Acceleration; Aqueous solutions; Carbon; Carbon tetrachloride; Cavitation; Chloral; chloral hydrate; dosimetry; Potassium iodides; Spectrophotometry; Ultrasonic imaging; Weissler reaction
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.202000294

The Weissler reaction, in which a potassium iodide aqueous solution is oxidized to produce triiodide ion, is a conventional means of quantifying ultrasound‐induced inertial cavitation. The reaction is commonly accelerated by saturating the solution with carbon tetrachloride, thereby increasing triiodide ion yields for any given ultrasound exposure. Chloral hydrate, being less toxic and easier to handle, is an alternative accelerant that was characterized. Observed triiodide ion levels were around 11–15% of that produced with carbon tetrachloride. Chloral hydrate was shown to be less susceptible to accelerant exhaustion for prolonged measurements. Spectrophotometric measurement of triiodide ion is typically performed through absorbance measurements at 350 nm; however, there is a separate absorption peak at 288 nm. Measurements at 288 nm were strongly correlated with 350 nm measurements. Due to the greater molar absorptivity at 288 nm, Weissler reaction measurements in the future may be preferably conducted at this alternative wavelength regardless of the means of acceleration. The Weissler reaction is commonly used to measure ultrasonically induced inertial cavitation. Produced triiodide ion is usually quantified through spectrophotometry at 350 nm. Carbon tetrachloride is the typical reaction accelerant. Chloral hydrate is an alternative. Yields using each were compared. Triiodide ion has a higher absorptivity peak at 288 nm; therefore, future measurements may be preferentially conducted there.