Etilo alkoholio denatūranto denatonio benzoato nustatymas kapiliarinės skysčių chromatografijos metodu naudojant ištisinį polimerinį sorbentą
| Date |
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2008 |
Šiame straipsnyje aptariamas kapiliarinės skysčių chromatografijos (KSC) su ištisiniu (monolitiniu) polimeriniu sorbentu metodas bitrekso analizei. Ištirti aštuoni etilo alkoholio bandiniai, kuriuose buvo nustatyta bitrekso koncentracija. Taip pat nustatyta ir palyginta bitrekso koncentracija viršutinėje bei apatinėje indo su alkoholiu dalyje. Po 24 h laikymo viršutiniame sluoksnyje bitrekso koncentracija tampa mažesnė nei bendra jo koncentracija (sumaišytame) bandinyje. Apatiniame sluoksnyje bitrekso koncentracija laikant parą laiko gali padidėti iki dviejų ir daugiau kartų. Įvertinta denatonio benzoato aptikimo riba sudarė 0,17 mg/l, o nustatymo riba – 0,29 mg/l. Nustatytas bitrekso nustatymo linijinis intervalas KSC metodu etilo alkoholyje buvo nuo 0,17 mg/l iki 36,6 mg/l. Ištirti keturių prekių mėginiai, kuriuose vienas iš komponentų yra denatūruotas alkoholis.
Denatonium benzoate was discovered by Macfarlan Smith in 1958. Later it was used as a denaturant in ethyl alcohol. Evaluation of denatonium benzoate (bitrex) concentration in the denatured ethyl alcohol and different products is of high importance. Bitrex concentration in ethyl alcohol, according to Lithuanian list of denaturants, has to be from 3 to 20 mg/L. Generally HPLC is used for the analysis of denatonium benzoate in denatured alcohol, in some cases CE is applied. In one HPLC application, the silica based continuous bed RP-18e (Merck, Germany) was used as a stationary phase of analytical column. Neither capillary chromatography nor acrylamide based continuous bed was used for the analysis of denatonium benzoate. For the first time we applied capillary liquid chromatography and acrylamide based continuous bed for the evaluation of denatonium benzoate in denatured alcohol. Eight samples of denatured alcohol were analyzed. Concentration of bitrex was evaluated at the top and bottom of the storage vessel and compared to average concentration of extensively mixed primary sample. It was found that bitrex concentration in these layers is different. After storage for 24 hours in the top layer bitrex concentration is lower than average bitrex concentration in the mixed sample and at the bottom bitrex concentration can be twice and more times higher than the average concentration. The limits of detection of the method was 0.17 mg/l and limit of quantification 0.29 mg/l. Good linearity was obtained for the concentration range 0.17 mg/l - 36.6 mg/l. Four samples of the products, where one of the components was denatured alcohol, were analyzed.