Problems of Forensic Sciences 2005 Vol. 63 (LXIII) 275-287
DETERMINATION OF DENATONIUM BENZOATE (BITREX) IN DENATURED SPIRIT PREPARATIONS
Dariusz ZUBA, Czesława ŚWIEGODA, Bogumiła BYRSKA, Wojciech LECHOWICZ
Institute of Forensic Research, Krakow
Streszczenie
The aim of the study was to elaborate a chromatographic method for determination of denatonium benzoate (Bitrex) in spirits intended for industrial purposes as well as in products prepared on the basis of denatured spirit, such as windscreen washers, disinfectants, alcoholic solvents, or barbecue lighting fluid. High-performance liquid chromatography (HPLC) was applied to detection and quantitative analysis of denatonium benzoate in spirit products. Separation was performed on a Chromolith Performance RP-18e (100 x 4.6 mm) column, in gradient conditions, with the use of 0.01% aqueous solution of phosphoric acid and acetonitrile as the eluents. Identification of components was carried out using a spectrophotometric detector with a diode-array matrix (DAD). The presence of denatonium benzoate in spirits was confirmed by mass spectrometry (MS). Liquid samples were introduced directly into the ionisation chamber of the spectrometer. Both positive (ES+) and negative (ES–) ionisation mode were applied. The capillary voltage was 3.0 kV and the CID zone voltage was 15 V. The worked-out procedure of spirits examination for the denatonium benzoate content is straightforward and fast. It enables examination of colourless liquids without preliminary sample preparation, or, possibly, just with centrifugation of the sample. The determined limit of quantitation was 0.3 mg/l, i.e. ten times lower than the minimal amount of denatonium benzoate, which the denatured spirits should contain according to the decree of the Ministry of Agriculture and Rural Development (0.3 g/100 l of 100% alcohol). The above method is used in routine examinations performed at the Institute of Forensic Research.
Słowa kluczowe
Denatured spirit; Denatonium benzoate; Purification.