ELECTROCHEMICAL TECHNIQUE FOR 1, 3-DICHLORO-2-PROPANOL ANALYSIS

Abstract

Soy sauce is widely used as a seasoning for many kinds of food. 1,3 Dichloro-2-propanol (1,3-
DCP) is a toxic, semi-volatile organic liquid that is soluble in water and organic solvent. It is used in a large
quantity as an intermediate in epichlorohydrin production. 1,3-DCP is a major raw material in the chemical
paper industry, but it is a problem in the production of foods, such as soy sauces and other acid-hydrolyzed
vegetable proteins. The normal method to analyze 1,3-DCP is an expensive and time-consuming GC-MS
technique using a highly purified sample. Our purpose was to reduce the expense and time of the analysis.
Therefore, this research focused on improvement of 1,3-DCP analysis methodology by using an
electrochemical technique. We produced a carbon paste electrode, which was used as the working electrode.
We studied the suitable conditions for analysis by using a voltammetry technique; electric potential and
NaOH in oxidation reaction of 1,3-DCP and an amperometry technique; interval time of reaction at electrode
surface (5 and 10 minutes), stirring rate (100, 300 and 500 rpm). It was found that the electric potential and
the interval time of oxidation reaction for 1,3-DCP analysis were 1.3 V. and 5 minute intervals, respectively.
Moreover, we found that 4.0 M NaOH and 100 rpm stirring rate were suitable for this analysis. The result of
our research were 0.02 mg/dm3 detection limit, 81.27 % recovery, 13.339 ppm sensitivity, 0.67-4.67 ppm
linear range, 6.95 % RSD of solution preparation, 3.95 % RSD of injection and 5.15 % RSD of the carbon
paste working electrode.