Use of a stopped-flow technique for investigation and determination of thiourea and its N-methyl derivatives as inducers of the iodine-azide reaction.
A stopped-flow technique has been used to investigate the behaviour of 2-thiourea, 1-methyl-2-thiourea, 1,3-dimethyl-2-thiourea, and 1,1,3,3-tetramethyl-2-thiourea in the induced iodine-azide reaction. This technique enables the progress of the reaction to be followed by monitoring the decrease in the absorbance of the iodine-starch complex at 595 nm. The effect of the concentration of the reagents on the rate of the reaction was investigated and a kinetic method for determination of the compounds is proposed. 2-Thiourea, 1-methyl-2-thiourea, and 1,3-dimethyl-2-thiourea can be determined in the range 3-75 micromol L(-1) and 1,1,3,3-tetramethyl-2-thiourea in the range 2-200 micromol L(-1).
Institute of Chemistry, Poznań University of Technology, ul. Piotrowo 3, 60-965, Poznań, Poland. jan.kurzawa@put.poznan.pl
Jan
J
Kurzawa
Krystyna
K
Janowicz